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Samacheer Kalvi 10th Science Model Question Paper 3 English Medium

Leave a Comment / Class 10 / By Prasanna

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Tamil Nadu Samacheer Kalvi 10th Science Model Question Paper 3 English Medium

General Instructions:

The question paper comprises of four parts
You are to attempt all the questions in each part. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III and IV are to be attempted separately.
Question numbers 1 to 12 in Part I are Multiple Choice Questions of one mark each.
These are to be answered by writing the correct answer along with the corresponding option code.
Question numbers 13 to 22 in Part II are of two marks each. Any one question should be answered compulsorily.
Question numbers 23 to 32 in Part III are of four marks each. Any one question should be answered compulsorily.
Question numbers 33 to 35 in Part IV are of seven marks each. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 75

Part – I

(i) Answer all the questions. [12 × 1 = 12]
(ii) Choose the most suitable answer and write the code with the corresponding answer.

Question 1.
One kilogram force equal to _______.
(a) 9.8 dyne
(b) 9.8 × 10⁴N
(c) 98 × 10⁴ dyne
(d) 980 dyne
Answer:
(c) 98 × 10⁴ dyne

Question 2.
Temperature is the average ______ of the molecules of a substance.
(a) difference in K.E and P.E
(b) sum of P.E and K.E
(c) difference in T.E and P.E
(d) difference in K.E and T.E
Answer:
(c) difference in T.E and P.E

Question 3.
In nuclear reactor _____ is used as a control rod.
(a) barium
(b) carbon
(c) cadmium
(d) Na
Answer:
(c) cadmium

Question 4.
Mass of 1 mole of Nitrogen atom is ______.
(a)28 amu
(b) 14 amu
(c) 28 g
(d) 14 g
Answer:
(b) 14 amu

Question 5.
Which of the following law inert gases 2 electrons in the outermost shell?
(a) He
(b) Ne
(c) Ar
(d) Kr
Answer:
(a) He

Question 6.
The number of components in a binary solution is ________.
(a) 2
(b) 3
(c) 4
(d) 5
Answer:
(a) 2

Question 7.
In an healthy adult during normal resting condition the blood pressure is ______.
(a) 160 mm/80 mm Hg
(b) 140 mm/80 mm Hg
(c) 120 mm/80 mm Hg
(d) 140 mm/60 mm Hg
Answer:
(c) 120 mm/80 mm Hg

Question 8.
Coronary heart disease is due to ______.
(a) Streptococci bacteria
(b) Inflammation of pericardium
(c) Weakening of heart valves
(d) Insufficient blood supply to heart muscles
Answer:
(d) Insufficient blood supply to heart muscles

Question 9.
Glycolysis takes place in _______.
(a) Cytoplasm
(b) Mitochondria
(c) Inner mitochondrial membrane
(d) Nucleus
Answer:
(a) Cytoplasm

Question 10.
________ is the ATP factory of the cell.
(a) Mitochondria
(b) Chloroplast
(c) Ribosomes
(d) Nucleus
Answer:
(a) Mitochondria

Question 11.
The “use and disuse theory” was proposed by ________.
(a) Charles Darwin
(b) Ernst Hacc Kel
(c) Jean Baptiste Lamark
(d) Gregor Mendel
Answer:
(c) Jean Baptiste Lamark

Question 12.
Which is used to edit programs?
(a) Inkscape
(b) Script editor
(c) Stage
(d) Sprite
Answer:
(b) Script editor

Part – II

Answer any seven questions. (Q.No: 22 is compulsory) [7 × 2 = 14]

Question 13.
Define moment of a couple.
Answer:
When two equal and unlike parallel forces applied simultaneously at two distinct points constitute couple. A couple results in causes the rotation of the body. This rotating effect of a couple is known as moment of a couple.

Question 14.
What is power of accommodation of eye?
Answer:

The ability of the eye lens to focus nearby as well as the distant objects is called power of accommodation of the eye.
This is achieved by changing the focal length of the eye lens with the help of ciliary muscles.

Question 15.
What are the advantages of LED TV over the normal TV?
Answer:

It has bright picture quality
It is thinner in size
It uses less power and consumes very less energy.
Its life span is more
It is more reliable

Question 16.
State Ohm’s law.
Answer:
According to Ohm’s law, at a constant temperature, the steady current ‘I’ flowing through a conductor is directly proportional to the potential difference ‘V’ between the two ends of the conductor. V = IR

Question 17.
Distinguish between the saturated and unsaturated solution.
Answer:

Saturated solution	Unsaturated solution
1. A solution in which no more solute can be dissolved in a definite amount of the solvent at a given temperature is called a saturated solution.	1. Unsaturated solution is one that contains less solute than that of the saturated solution at a given temperature.
2. e.g. 36 g of NaCl in 100 g of water at 25°C	2. e.g. 16 g of NaCl in 100 g of water at 25°C

Question 18.
Why is the teeth of rabbit called heterodont?
Answer:
In Rabbit, the teeth are of different types, i.e., Incisors, (I) Canines (C), Premolar (PM) and molar (M). Hence the dentition is called heterodont.

Question 19.
What is the function of Oxytocin?
Answer:
Oxytocin helps in the contraction of the smooth muscles of uterus at the time of child birth and milk ejection from the mammary gland after child birth.

Question 20.
What will happen if you cut planaria into small fragments?
Answer:
If you cut planaria into small fragments, each fragment will develop into new individual by a specialised mass of cell. It is called regeneration.

Question 21.
Match the following:

Answer:
(a) ii
(b) iii
(c) iv
(d) i

Question 22.
How much current will an electric heater coil draw from 220 V source, if the resistance of heater coil is 110Ω.
Answer:
Given,V = 220 V, R = 110 Ω; I = ?
I = $\frac{V}{R}=\frac{220}{110}$ = 2A

Part – III

Answer any seven questions (Q.No: 32 is compulsory) [7 × 4 = 28]

Question 23.
What are the types of inertia? Give an example for each type.
Answer:

Inertia of rest: The resistance of a body to change its state of rest is called inertia of rest. E.g: When you vigorously shake the branches of a tree, some of the leaves and fruits are detached and they fall down.
Inertia of motion: The resistance of a body to change its state of motion is called inertia of motion. E.g: An athlete runs some distance before jumping. Because, this will help him jump longer and higher.
Inertia of direction: The resistance of a body to change its state of direction is called inertia of direction.
E.g: When you make a sharp turn while driving a car, you tend to lean sideways.

Question 24.
Explain the rules for obtaining images formed by a convex lens with the help of ray diagram.
Answer:
Rule-1: When a ray of light strikes the convex lens obliquely at its optical centre, it continues to follow its path without any deviation

Rule-2: When a ray of light passes parallel to the principal axis of convex lens, the refracted rays is converged to the principal focus

Rule-3: When a ray passing through the principal focus the refracted ray will be parallel to the principal axis

Question 25.
A piece of wire of resistance 10 ohm is drawn out so that its length is increased to three times its original length. Calculate the new resistance.
Answer:
Specific resistance (ρ) = $\frac{\mathrm{RA}}{l}$
R = $\frac{\rho l}{\mathrm{A}}$
When the length is increased by three and then the area of cross section is reduced by threeResistance of wire R = 10 Ω
New resistance R’ = $\frac{\rho(3 l)}{(A / 3)}$
= ρ (3l) x $\frac{3}{\mathrm{A}}$
R’ = $\frac{9 \rho l}{\mathrm{A}}$
R’ = 9 × R = 9 × 10
R’ = 90 Ω

Question 26.
Write briefly about the characteristics of hydrocarbons.
Answer:

Lower hydrocarbons are gases at room temperature E.g. methane, ethane.
They are colourless and odourless.
The boiling point of hydrocarbons increases with an increase in the number of carbon atoms.
They undergo combustion reaction with oxygen to form CO₂ and water.
Alkanes are least reactive when compared to other classes of hydrocarbons.
Alkynes are the most reactive due to the presence of the triple bond.
Alkanes are saturated whereas alkenes and alkynes are unsaturated.
They are insoluble in water.

Question 27.
(i) What is Hydrated salt?
Answer:

When ionic substances are dissolved in water to make their saturated aqueous solution, their ions attract water molecules and attached chemically in certain ratio. This process is called hydration.
These ionic substances crystallize out from their saturated aqueous solution with a definite number of molecules of water.
The number of water molecules found in the crystalline substance is called water of crystallization.
Such salts are called hydrated salts
Eg. Blue vitriol – CuSO₄.5H₂O

(ii) How is ethanoic acid prepared from ethanol? Give the chemical equation?
Answer:
Ethanoic acid is prepared by the oxidation of ethanol in the presence of alkaline potassium permanganate or acidified potassium dichromate.

Question 28.
Differentiate voluntary and involuntary action.
Answer:
Voluntary Action:

Voluntary Action	Involuntary Action
1. Controlled by Cerebrum	1. Controlled by the spinal cord.
2. The actions are under the control of our will	2. The actions, are not under our control
3. Eg. Writing, speaking	3. Eg. Heart beat, Breathing

Question 29.
(a) Lable the parts of DNA in the diagram below. Explain the structure briefly.
Answer:

DNA is a Polynucleotide. Each nucleotide contains
(i) A sugar molecule – Deoxyribose sugar

(ii) A nitrogenous base. They are two types of nitrogeneouS bases. They are

Purines (Adenine and Guanine)
Pyrimidines (Cytosine and Thymine)

(iii) A phosphate group
Nucleoside = Nitrogen base + sugar
Nucleotide – Nucleoside + Phosphate
Purines and pyrimidines are linked by hydrogen bonds.
Adenine (A) links thymine (T) with two hydrogen bonds (A = T)
Cytosine (C) links Guanine (G) with three hydrogen bonds (C ≡ G)

(b) Enumerate any 4 functions of blood.
Answer:
Functions of blood:

Transport of respiratory gases (Oxygen and CO₂).
Transport of hormones.
It maintains proper water balance in the body.
It acts as buffer and also helps in regulation of pH and body temperature

Question 30.
(a) What is photosynthesis? Where does it occur?
Answer:
Photosynthesis is a process by which autotrophic organism like green plants algae and chlorophyll containing bacteria utilize the energy from sunlight to synthesize their own food. Photosynthesis occur in green parts of the plant such as leaves, stems and floral buds.

(b) Write the reaction for photosynthesis?
Answer:

Question 31.
(a) What are the contributing factors for obesity?
Answer:
The contributing factors for obesity.

Genetic factors
physical inactivity
Eating habits(Over eating)
endocrine factors

(b) What is genetic engineering?
Answer:
Genetic engineering is the manipulation and transfer of genes from one organisms to another organisms to create a new DNA is called as recombinant DNA (rDNA). The Genetic engineering is also called as recombinant DNA technology.

Question 32.
(a) Explain linear expansion with equation.
Answer:
When a body is heated or cooled, the length of the body changes due to the change in its temperature. Then the expansion is said to be linear or longitudinal expansion. The ratio of increase in length of the body per degree rise in temperature to its unit length is called as the coefficient of linear expansion.

The value of coefficient of linear expansion is different for different materials. The equation relating the change in length and the change in temperature of a body is

$\frac{\Delta L}{L_{0}}$ = α_LΔT
Δ L-Change in length a
L₀ – Original length
ΔT – Change in temperature
α_L – Coefficient of linear expansion.

(b) State Avogadro’s law.
Answer:
Equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules.

Part – IV

(1) Answer all the questions. [3 × 7 = 21]
(2) Each question carries seven marks.
(3) Draw diagram wherever necessary.

Question 33.
(a) With the help of a circuit diagram derive the formula for the resultant resistance of three resistances connected in series.
Answer:

Let, three resistances R₁, R₂ and R₃ be connected in series. Let the current flowing through them be I. According to Ohm’s Law, the potential differences V₁, V₂ and V₃ across R₁, R₂ and R₃ respectively, are given by:
V₁ = IR₁ …….. (1)
V₂ = IR₂ …….. (2)
V₃ = IR₃ ……. (3)
The sum of the potential differences across the ends of each resistor is given by
V = V₁ + V₂ + V₃
Using equations (1), (2) and (3), we get
V = IR₁ + IR₂ + IR₃ …… (4)
The effective resistor is a single resistor, which can replace the resistors effectively, so as to allow the same current through the electric circuit. Let, the effective resistance of the series-combination of the resistors, be R_s.
Then,
V = IR_s …….. (5)
Combining equations (4) and (5) we get,
IR_s = IR₁ +IR₂ + IR₃
R_s = R₁ + R₂ + R₃ …… (6)
Thus, When a number of resistors are connected in series, their effective resistance is equal to the sum of the individual resistances.
When ‘n’ resistors of equal resistance R are connected in series, the equivalent resistance is ‘n R’ i.e., R_s = n R
The equivalent resistance in a series combination is greater than the highest of the individual resistances.

[OR]

(b) (i) An object of height 3 cm is placed at 10 cm from a concave lens of focal length 15 cm. Find the size of the image.
Answer:

Given, $\frac{1}{f}=\frac{1}{v}-\frac{1}{u}$
f = -15 cm [left side of lens]
u =-10 cm [left side of lens]

(ii) The thunder of cloud is heard 9.8 seconds later than the flash of lightning. If the speed of sound in air is 330 ms-1. What will be the height of the cloud?
Answer:
Given, Time, t = 9.8 s
Speed of sound,v = 330 ms^-1
Height of cloud, d = ?
v = d/t,
d = vt
= 330 × 9.8
d = 3234 m

Question 34.
(i) What is the mass of 1 mole of nitrogen atom?
(ii) How many moles of SO₂ have same mass as 3 moles of oxygen?
(iii) How many molecules are present in 1 ml of water?
Answer:
(i) 1 × gram atomic mass of nitrogen atom
1 × 14 = 14 g

(ii) Mass of 3 moles of oxygen = 3 × 16 = 48 g
Now, mas of SO₂ = 32 + [2 × 16]
= 32 + 32 = 64 g
∴ 64 g of SO₂ = 1 mole
48 g SO₂ = ($\frac{1}{64}$) × 48 = 0.75 mole

(iii) We know that density of water is 1 g /ml
Hence, 1 g water = 1 ml water
Now, We have molecular mass of water
H₂O = (1 × 2) + 16 = 18 g
18 g of water contains 6.022 × 10²³ molecules
1 g of water will contains = $\frac{6.023 \times 10^{23}}{18}$ = 0.33 × 10²³ molecules
So the number of molecules of water in 1 ml = 3.3 × 10²²

[OR]

(b) Explain the factors influencing the rate of a reaction.
Answer:
The factors influencing the rate of a reaction are,
(i) Nature of the reactants: The reaction of sodium with hydrochloric acid is faster than that with acetic acid. Do you know why? Hydrochloric acid is a stronger acid than acetic acid and thus more reactive. So, the nature of the reactants influence the reaction rate.
2Na_(s) + 2HCl_(aq) → 2NaCl_(aq) + H_2(g) (fast)
2Na_(s) + 2CH₃COOH_(aq) → 2CH₃COONa_(aq) + H_2(g) (slow)

(ii) Concentration of the reactants: Changing the amount of the reactants also increases the reaction rate. The amount of the substance present in a certain volume of the solution is called ‘concentration’. More particles per volume exist in it and hence faster the reaction. Granulated zinc reacts faster with 2M hydrochloric acid than 1M hydrochloric acid.

(iii) Temperature: Most of the reactions go faster at higher temperature. Because adding heat to the reactants provides energy to break more bonds and thus speed up the reaction. Calcium carbonate reacts slowly with hydrochloric acid at room temperature. When the reaction mixture is heated the reaction rate increases.

(iv) Pressure: If the reactants are gases, increasing their pressure increases the reaction rate. This is because, on increasing the pressure the reacting particles come closer and collide frequently.

(v) Catalyst: A catalyst is a substance which increases the reaction rate without being consumed in the reaction. In certain reactions, adding a substance as catalyst speeds up the reaction. For example, on heating potassium chlorate, it decomposes into potassium chloride and oxygen gas, but at a slower rate. If manganese dioxide is added, it increases the reaction rate.

(vi) Surface area of the reactants: When solid reactants are involve in a reaction, their powdered form reacts more readily. For example, powdered calcium carbonate reacts more readily with hydrochloric acid than marble chips. Because, powdering of the reactants increases the surface area and more energy is available on collision of the reactant particles. Thus, the reaction rate is increased.

Question 35.
(a) (i) Write any 4 physiological effects of gibberellins.
(ii) Name the enzyme present in acrosome of sperm? What is its function.
(iii) What are the consequences of deforestation.
Answer:
(i) Physiological effects of gibberellins

Gibberellins promote the production of male flowers in monoecious plants (Cucurbits).
Gibberellins break dormancy of potato tubers.
Gibberellins are efficient in inducing the formation of seedless fruit (Parthenocarpic fruits).
Gibberellins stimulate extraordinary elongation of internode Eg.Corn and pea.

(ii) An enzyme, Hyaluronidase present in the acrosome help the sperm to enter the ovum during fertilization.

(iii) Deforestation is the destruction of large area of forests. It gives rise to ecological problems like floods, drought, soil erosion, loss of wild life, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification. Therefore it is a threat to the economy, quality of life and future of the environment.

[OR]

(b) (i) List out any 3 parasitic adaptation of leech.
(ii) Explain the importance of Fossils.
Answer:
(i) Parasitic adaptation of Leech:

Blood is sucked by pharynx
The salivary glands produce hirudin which does not allow the blood to coagulate.
Anterior and posterior ends of the body are provided with suckers by which the animal attaches itself to the body of the host.

(ii) Importance of Fossils:

Fossils are useful in classification of plants.
Fossils throw light on phytogeny and evolution of plants
Fossil plants give a historical approach to plant kingdom
Fossil plants can be used in the field of descriptive and comparative anatomy

Samacheer Kalvi 12th Computer Applications Solutions Chapter 4 Introduction to Hypertext Pre-Processor

Leave a Comment / Class 12 / By Prasanna

Students can Download Computer Applications Chapter 4 Introduction to Hypertext Pre-Processor Questions and Answers, Notes Pdf, Samacheer Kalvi 12th Computer Applications Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 12th Computer Applications Solutions Chapter 4 Introduction to Hypertext Pre-Processor

Samacheer Kalvi 12th Computer Applications Introduction to Hypertext Pre-Processor Text Book Back Questions and Answers

PART – I
I. Choose The Correct Answer

Question 1.
What does PHP stand for?
(a) Personal Home Page
(b) Hypertext Preprocessor
(c) Pretext Hypertext Processor
(d) Pre-processor Home Page
Answer:
(b) Hypertext Preprocessor

Question 2.
What does PHP files have a default file extension?
(a) html
(b) xml
(c) .php
(d) ph
Answer:
(c) .php

Question 3.
A PHP script should start with ……………………. and end with …………………….
(a) <php>
(b) < ? php ?>
(c) < ? ? >
(d) < ?php ? >
Answer:
(d) < ?php ? >

Question 4.
Which of the following must be installed on your computer so as to mn PHP script?
(a) Adobe
(b) windows
(c) Apache
(d) IIS
Answer:
(c) Apache

Question 5.
We can use ………………….. to comment a single line?
(i) /?
(ii) 11
(iii) #
(iv) /* */
(a) Only (ii)
(b) (i), (iii) and (iv)
(c) (ii), (iii) and (iv)
(d) Both (ii) and (iv)
Answer:
(c) (ii), (iii) and (iv)

Question 6.
What will be the output of the following PHP code?
Ans
< ?php
$num =1;
$num1 =2;
print $num . $num1 ;
?>
(a) 3
(b) 1+2
(c) 1.+.2
(d) Error
Answer:
(a) 3

Question 7.
Which of the following PHP statements Will output Hello World on the screen?
(a) echo (“Hello World”)
(b) print (“Hello World”)
(c) printf (“Hello World”)
(d) sprintf (“Hello World”)
Answer:
(a) echo (“Hello World”)

Question 8.
Which statement will output $x on the screen?
(a) echo “\$x”
(b) echo “$$x”
(c) echo “/$x”
(d) echo “$x
Answer:
(a) echo “\$x”

Question 9.
Which of the below symbols is a newline character?
(a) \r
(b) \n
(c) /n
(d) /r
Answer:
(b) \n

PART – II
II. Short Answers

Question 1.
What are the common usages of PHP?
Answer:

It is very simple and lightweight open source server side scripting language.
It can easily embed with HTML and other client side scripting languages like CSS (Cascading Style Sheets) and Java script.
It also creates dynamic and interaction Webpages in the red time Web development projects.

Question 2.
What is Webserver?
Answer:
Web server software is available as open source or licensed version in the market. A Web server is a Software that uses HTTP (Hypertext Transfer Protocol) to serve the files that form Web pages to users.

Question 3.
What are the types scripting language?
Answer:
Web scripting languages are classified into two types, client side and server side scripting language. PHP is completely different from Client side scripting language like Java script. The PHP code entirely executes on Webserver which is installed in the remote machine.

Question 4.
Difference between Client and Server?
Answer:
The server is a high performance hardware machine it could run more than one application concurrently. The client is a separate hardware machine which is connected with server in the network (Intemet/intranet). It could send the request and receive the response from the server hardware. The Server and client are also called as service provider and service requester respectively.

Question 5.
Give few examples of Web Browser?
Answer:
Internet Explorer
UC Browser
Opera
Google Chrome and
Mozilla Firefox.

Question 6.
What is URL?
Answer:
URL: Uniform Resource Locator, the address of a specific Web page or file on the Internet. Eg. http://example.com

Question 7.
Is PHP a case sensitive language?
Answer:
Yes, smaller case & uppercase letters are different in PHP.

Question 8.
How to declare variables in PHP?
Answer:
The variable in PHP begins with a dollar ($) symbol and the assignment activity implemented using “=” operator, finally the statement ends with semi colon The semicolon indicates the end of statement.
$a=5; $b=T0;

Question 9.
Define Client Server Architecture?
Answer:
The client server architecture introduces application sharing mechanism between two different hardware systems over the network (Intemet/intranet).

Question 10.
Define Webserver?
Answer:
Web server software is available as open source or licensed version in the market.
A Web server is a Software that uses HTTP (Hypertext Transfer Protocol) to serve the files that form Web pages to users.

PART – III
III. Explain in Brief Answer

Question 1.
Write the features of server side scripting language?
Answer:

The server is a high performance hardware machine it could run more than one application concurrently.
Most of the server side scripting languages are working on any one the client server architecture model.
Webserver is software which is running in server hardware.
It takes the responsibilities for compilation and execution of server side scripting languages.

Question 2.
Write is the purpose of Web servers?
Answer:

Webserver is software which is running in server hardware.
It takes the responsibilities for compilation and execution of server side scripting languages.
After receiving the request from client machine the Web server tries to compile and interpret the PHP code which is available in remote machine.
Next a response will be generated and sent back to the client machine over the network from Webserver.

Question 3.
Differentiate Server side and Client Side Scripting language?
Answer:
Server Side Scripting Language:

Server is a high performance hardware machine. It could run more than one application concurrently.
The server is the service provider.
Ex. Php. Asp.net, Python, Cold Fusion
It is relatively secure

Client Side Scripting Language:

The client is a separate hardware machine which is connected with server in the network.
The client is the service requester
html, css, Javascript
Insecure

Question 4.
In how many ways you can embed PHP code in an HTML page?
Answer:

PHP script can be written in side of HTML code and save the file with extension of .php. The embedded PHP file get executed in the Webserver, the browser receives only the HTML and other client side files.
Php files can also be embedded with css and js files.
Using template engines like Smarty, DWOO, Mustache, Blade we can embed php files.

Question 5.
Write short notes on PHP operator?
Answer:
Operator is a symbol which is used to perform mathematical and logical operations in the programing languages. Different types of operator in PHP are:

Arithmetic operators
Assignment operators
Comparison operators
Increment/Decrement operators,
Logical operators, and
String operators.

PART – IV
IV. Explain in detail

Question 1.
Explain client side and server side scripting language?
Answer:

PHP (Hypertext Pre-processor) is a one of the important server side Web and general purpose scripting language invented by Rasmus Lerdorf in 1994.
It is very simple and lightweight open source server side scripting language.
It can easily embed with HTML and other client side scripting languages like CSS (Cascading Style Sheets) and Java script.
It also creates dynamic and interactive Webpages in the real time Web development projects
Web scripting languages are classified into two types, client side and server side scripting language.
PHP is completely different from Client side scripting language like Java script.
The PHP code entirely executes on Webserver which is installed in the remote machine and it is generating HTML code which is sent to the user.
The user receives the HTML code and sees the Website contents via Internet browser in their computer or laptop.
PHP also supports OOPs (Object Oriented Programing) concepts. It is applicable to implement all OOPs features such as class, object and inheritance etc. The action is shown in Figure.

Question 2.
Discuss in detail about Website development activities?
Answer:
The process of development also includes Web content generation, Web page designing, Website security and so on.
PHP Script:
1. Website or Web page is developed by the programmer using PHP script. Finally the entire Website codes are moved to Web server path in a remote server machine.

2. From client side, the end user opens a browser, types the URL of the Website or Webpage and initiates the request to remote server machine over the network.

3. After receiving the request from client machine the Web server tries to compile and interpret the PHP code which is available in remote machine.

4. Next a response will be generated and sent back to the client machine over the network from Webserver.

5. Finally the browser which is installed in the client machine receives the response and displays the output to user.

Question 3.
Explain the process of Webserver installation?
Answer:
Web server software that runs on server hardware, governs the server side scripting compilation into an intermediate byte-code that is then interpreted by the runtime engine.

Web server software is available as open source or licensed version in the market. Recent statistics of Web server usage depict that more than 130% Websites are running under the open source Web servers such as Tomcat Apache, Nginx etc. The following are the steps to install and configure Apache Httpd Webserver and PHP module in windows server machine.

Step 1:
Go to Apache foundation Website and download the Httpd Webserver Software.
https://httpd.apache.org/download.cgi

Step 2:
After downloading .MSI file from Apache foundation Website, user launches the. MSI file and clicks next and next button to finish the installation on server machine. The software takes default port number 130 or 130130. Once the user finished, the Web server software is installed and configured on server hardware machine as a service.

Step 3:
To test the installation of Apache Httpd Webserver, enter the following URL from your Web browser which is installed in your client machine.
https://localhost:130/ or https://localhost: 130130 The output page that says “Its works”

Step 4:
Administrator user can start, stop and restart the Web server service at any time via windows Control panel. Once the services stops, the client machine will not receive the response message from server machine.

Step 5:
Webserver’s configuration setting “httpd.conf” file is located in the conf directory under the apache installation directory. Edit this file and enable the PHP module to run PHP scripting language.

Question 4.
Discuss in detail about PHP data types?
Answer:
PHP Data type:
PHP scripting language supports 13 primitive data types. Data Types plays important role in all programing languages to classify the data according to the logics. PHP supports the following data types.

String
Integer
Float
Boolean
Array
Object
NULL
Resource

1. String:
String is a collection of characters within the double or single quotes like
“Computer Application” or ‘Computer Application’. Space is also considered as a character.
Example:
$x = “Computer Application!”;

2. Integer:
Integer is a data type which contains non decimal numbers.
Example:
$x = 59135;
*
The var_dump( ) system define function, returns structured information (type and value) about variables in PHP.

3. Float:
Float is a data type which contains decimal numbers.
Example:
$x = 19.15;

4. Boolean:
Boolean is a data type which denotes the possible two states, TRUE or FALSE
Example:
$x = true;
$y = false;

5. Array:
Array is a data type which has multiple values in single variable.
Example:
Scars = array(“Computer”,“Laptop”,“Mobile”);

OUTPUT:
array(3) {[0]=> string(5) “Computer” [1]=>
string(3) “Laptop “ [2]=> string(6)” Mobile”}
Var_dump:
The var_dump( ) function is used to dump information about a variable. This function displays structured information such as type and value of the given variable. Arrays and objects are explored recursively with values indented to show structure.

6. Object:
PHP object is a data type which contains information about data and function inside-the class.
<?php
class School {
function marks( ) {
$this->sec = “A”;
}
}
// create an object
$schoolobj = new School ( );
?>
OUTPUT
NULL

7. NULL:
Null is a special data type which contains a single,value: NULL
<?php $x = null;
?>
OUTPUT:
NULL

8. Resources:
Resource is a specific variable, it has a reference to an external resource. These variables hold specific handlers to handle files and database connections in respective PHP program.
<?php
// Open a file for reading
Shandle = fopen(“note.txt”, “r”);
var_dump($handle);
echo “<br>”;
// Connect to MySQL database server with
default setting
Slink = mysql_connect(“localhost”, “root”, “”);
var_dump($link);
?>

Question 5.
Explain operators in PHP with example?
Answer:
Operators in PHP:
Operator is a symbol which is used to perform mathematical and logical operations in the programing languages. Different types of operator in PHP are:

Arithmetic operators
Assignment operators
Comparison operators
Increment/Decrement operators
Logical operators, and
String operators.

1. Arithmetic operators:
The arithmetic operators in PHP perform general arithmetical operations, such as addition, subtraction, multiplication and division etc.

2. Assignment Operators:
Assignment operators are performed with numeric values to store a value to a variable. The default assignment operator is “=”. This operator sets the left side operant value of expression to right side variable.

3. Comparison Operators:
Comparison operators perform an action to compare two values. These values may contain integer or string data types (Number or Strings).

4. Increment and Decrement Operators:
Increment and decrement operators are used to perform the task of increasing or decreasing variable’s value. This operator is mostly used during iterations in the program logics.

5. Logical Operators:
Logical Operators are used to combine conditional statements.

6. String Operators:
Two operators are used to perform string related operations such as Concatenation and Concatenation assignment (Appends).

Samacheer Kalvi 12th Computer Applications Solutions Introduction to Hypertext Pre-Processor Additional Questions and Answers

I. Choose The Best Answer

Question 1.
Tim Benner’s Lee developed
(i) Internet
(ii) www
(iii) Javascript
(iv) css
(a) only (i)
(b) (i) and (ii)
(c) (i), (ii), (iii)
(d) (ii), (iii), (iv)
Answer:
(b) (i) and (ii)

Question 2.
……………………… Scripting languages was introduced to support Internet online business.
(a) Server
(b) Client
(c) Web
(d) Online
Answer:
(c) Web

Question 3.
Which one of the following is a fundamental part of any dynamic web page?
(a) HTML
(b) PHP
(c) CSS
(d) JS
Answer:
(b) PHP

Question 4.
PHP was invented by
(a) Rasmus Lerdoof
(b) Tim Berner’s Lee
(c) Bob Frankston
(d) Don Bricklin
Answer:
(a) Rasmus Lerdoof

Question 5.
CSS means
(a) combined script style
(b) cascading style sheets
(c) calculated spreadsheet
(d) consecutive script sheets
Answer:
(b) cascading style sheets

Question 6.
Pick the odd one out.
php, css, ASP, JSP
Answer:
CSS

Question 7.
ASP stands for
(a) All server pages
(b) All script pages
(c) Active server pages
(d) Active script pages
Answer:
(c) Active server pages

Question 8.
JSP means
(a) Joint Server photographs
(b) Java Server pages
(c) Java Script program
(d) Active script pages
Answer:
(b) Java Server pages

Question 9.
ASP is developed by
(a) Apache
(b) Apple
(c) Microsoft
(d) Macromedia
Answer:
(c) Microsoft

Question 10.
In which year php was developed?
(a) 1991
(b) 1992
(c) 1993
(d) 1994
Answer:
(d) 1994

Question 11.
Find the Incorrect statement:
(I) 78.9% of websites are developed by PHP Scripting Language.
(II) 2.2% of websites developed with Python.
Answer:
(II) 2.2% of websites developed with Python.

Question 12.
CGI stands for
(a) Common Gateway Interface
(b) Call Gateway Interrupt
(c) Cold Gateway Interface
(d) Client Gateway Interface
Answer:
(a) Common Gateway Interface

Question 13.
IIS is
(a) Interrupt Interface Service
(b) Intra Interface Service
(c) Intra Interface Service
(d) Internet Intranet Service
Answer:
(b) Intra Interface Service

Question 14.
PHP, 7.3 is released on
(a) Dec 30 2017
(b) Nov 30 2017
(c) Oct 30 2017
(d) Jan 30 2018
Answer:
(b) Nov 30’ 2017

Question 15.
Find the Correct one
(i) PHP is an open source
(ii) Apache tom cat supports PHP
(iii) MS-ITS Supports PHP
(a) Only (i) is true
(b) (ii), (iii) – True
(c) (i), (ii) – True
(d) (i), (ii), (iii) – True
Answer:
(d) (i), (ii), (iii) – True

Question 16.
The ……………………… is a high performance hardware machine it could run more than one application concurrently.
Answer:
Server

Question 17.
The ……………………… is a separate hardware machine which is connected with server in the networks.
Answer:
Client

Question 18.
Match the following
1. Webservers – (a) ASP
2. Server Scripting Language – (b) Server
3. Service provider – (c) Microsoft IIS
4. Service requester – (d) Client
(a) 1 -(c) 2-(a) 3-(b) 4-(d)
(b) 1-(a)2 (b) 3-(c) 4-(d)
(c) 1-(d)2-(c)3-(b)4-(a)
(d) 1-(d) 2-(a) 2-(b) 4-(c)
Answer:
(a) 1 -(c) 2-(a) 3-(b) 4-(d)

Question 19.
How many client server architecture models there?
(a) 2
(b) 3
(c) 4
(d) 5
Answer:
(b) 3

Question 20.
The ……………………… architecture is used for the server, accessed by client as two layer interactions.
Answer:
two tier

Question 21.
Statement I: Multi/Three tier Architecture is used for the server, accessed by client through more than one layer Interaction.
Statement 2: The programmer could decide the count of business logic layers according to the software requirement.
(a) I – True, II – False
(b) I – False, II – True
(c) I, II – Both True
(d) I, II – Both False
Answer:
(c) I, II – Both True

Question 22.
……………………… is a software which is running in server hardware.
Answer:
webserver

Question 23.
Which takes the responsibilities for compilation and execution of server side scripting languages?
(a) Client
(b) HTML
(c) JS
(d) Web Server
Answer:
(d) Web Server

Question 24.
How many clarifications of web scripting languages are there?
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Question 25.
OOP’S stands for ……………………………
Answer:
object oriented programming

Question 26.
How many percentage of websites are running under the open source web servers?
(a) 100%
(b) 70%
(c) 120%
(d) 130%
Answer:
(d) 130%

Question 27.
What is the default port number taken by the software after installation?
(a) 100
(b) 110
(c) 120
(d) 130
Answer:
(d) 130

Question 28.
Name the configuration setting file which is used to run PHP scripting language?
(a) httpk.conf
(b) httpd.conf
(c) httpp.conf
(d) httpdd.conf
Answer:
(b) httpd.conf

Question 29.
Under which directory httpd.conf file is located?
(a) configure
(b) config
(c) configuration
(d) conf
Answer:
(d) conf

Question 30.
How many types of PHP syntax are available?
(a) 1
(b) 2
(c) 3
(d) A
Answer:
(c) 3

Question 31.
Pick the odd one out
Default syntax, Shortcut Tags, Short Open Tags, HTML Script embed Tags
Answer:
Shortcut Tags

Question 32.
For short open tags, the admin has to enable settings in ………………………… file?
(a) init
(b) php
(c) initialise
(d) php.ini
Answer:
(d) php.ini

Question 33.
The short open tags begins with ………………………….. and closes with ……………………………
Answer:
<? and ?>

Question 34.
Find the correct statement.
1) The embedded PHP file gets executed by the web client.
2) The embedded PHP file get executed in the web server.
Answer:
2) The embedded PHP file get executed in the web server.

Question 35.
………………………….. are the storage locations which can store the values for the later manipulations in the program.
(a) typecast
(b) variables
(c) operand
(d) include
Answer:
(b) variables

Question 36.
The variable in PHP begins with a …………………….. symbol.
(a) $
(b) #
(c) II
(d) =
Answer:
(a) $

Question 37.
The statements in PHP ends with
(a) $
(b) =
(c) ;
(d) :
Answer:
(c) ;

Question 38.
Which one of the following statement is correct related to variable?
(a) data type is required
(b) data type is not required
Answer:
(b) data type is not required

Question 39.
Which is false?
(a) variable name can start with number
(b) variable name can never start with a number
Answer:
(a) variable name can start with number

Question 40.
How many primitive data types are there in PHP scripting language?
(a) 10
(b) 11
(c) 12
(d) 13
Answer:

Question 41.
Identify the Incorrect statements
Case (I) variables are used to classify the data according to the logics Case
(II) Data types are used to classify the data according to the logics
Answer:
Case (I) variables are used to classify the data according to the logics Case

Question 42.
Pick the odd one.
UNIQUE NULL OBJECT ARRAY
Answer:
UNIQUE

Question 43.
………………………. is a collection of characters within the double quotes or single quotes.
Answer:
String

Question 44.
Space is considered as a character.
(a) True
(b) False
Answer:
(a) True

Question 45.
How many possible values does Boolean data type has?
(a) 2
(b) 3
(c) 4
(d) 5
Answer:
(a) 2

Question 46.
Which datatype contains non-decimal numbers?
(a) Integer
(b) Float
(c) Boolean
(d) Octal
Answer:
(a) Integer

Question 47.
Which function gives information about the given variable?
Ans
(a) var( )
(b) variable( )
(c) var-dump( )
(d) vardump( )
Answer:
(c) var-dump( )

Question 48.
………………………… is a data type which contains information about data and function inside the class.
Answer:
object

Question 49.
What is the keyword used to create a class?
(a) class
(b) classes
(c) class name
(d) class tag
Answer:
(a) class

Question 50.
………………………… variables holds specific handlers to handle files and database connections
Answer:
Resource

Question 51.
………………………. is a symbol which is used to perform mathematical and logical operations.
Answer:
Operator

Question 52.
How many types of operators are there in PHP?
(a) 3
(b) 4
(c) 5
(d) 6
Answer:
(d) 6

Question 53.
Pick the odd one out.
(a) && || ! !=
(b) == == !=
Answer:
(a) != (b)=

Question 54.
Which one of the following is the modulus operator?
(a) +
(b) %
(c) ||
(d) !
Answer:
(b) %

Question 55.
Which is the default assignment operator?
(a) =
(b) ==
(c) ===
(d) ====
Answer:
(a) =

Question 56.
Pick the odd one out.
(a) +=
(b) *=
(c) >=
(d) %=
Answer:
(c) >=

Question 57.
Assignment operator set the …………………….. side operant value of expression to ……………………… side variable.
Answer:
left and right

Question 58.
Which operators compares two values?
(a) Arithmetic
(b) Increment
(c) Comparision
(d) Logical
Answer:
(c) Comparision

Question 59.
Match the following
1. And – (i) &&
2. Or – (ii) ||
3. Not – (iii) !
4. Not equal – (iv) image
(a) 1-(i) 2-(ii) 3-(iii) 4-(iv)
(b) 1-(iv) 2-(iii) 3 -(ii) 4-(iii)
Answer:
(a) 1-(i) 2-(ii) 3-(iii) 4-(iv)

Question 60.
Identify the wrongly matched pair.
(a) Equal – ==
(b) Not Equal – ! =
(c) Not Identical – <>
(d) Identical – ===
Answer:
(c) Not Identical – <>

Question 61.
Which operator is mostly used during iteration in the program logics.
(a) Increment
(b) Decrement
(c) both a & b
(d) none of these
Answer:
(c) both a & b

Question 62.
!$x is an example of …………………………… operator.
(a) And
(b) Or
(c) Not
(d) Xor
Answer:
(c) Not

Question 63.
Which operator combines conditional statements.
(a) Comparision
(b) Relational
(c) Resource
(d) Logical
Answer:
(d) Logical

Question 64.
The string concatenation operator is ………………………….
(a) +
(b) .
(c) -=
(d) – =
Answer:
(b) .

Question 65.
…………………………. Concatenation assignment operator.
Answer:
.. =

Question 66.
Concatenation assignment operator comes under
(a) Assignment
(b) String
(c) Character
(d) Logical
Answer:
(b) String

Question 67.
Which operator appends are text to the another?
(а) Character
(b) Assignment
(c) Strings
(d) Logical
Answer:
(c) Strings

Question 68.
Find the statement which is wrong?
(a) PHP is a security program language
(b) PHP is a Flexibility program language
(c) PHP is a platform dependent program language
(d) PHP is a Real-Time Access Monitoring programming language
Answer:
(c) PHP is a platform dependent program language

Question 69.
URL Stands for ………………………….
Answer:
Uniform Resource Locator

Question 70.
HTTP means ……………………….
Answer:
Hyper Text Transfer Protocol

II. Short Answers

Question 1.
Define Web browser?
Answer:
(i) Web Browser:
A Web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web.

(ii) Each individual Web page, image, and video is identified by a distinct URL, enabling browsers to retrieve and display them on the user’s device.

Question 2.
Name the three types of syntax available in PHP?
Ans
Three types of PHP Syntax are available. They are as follows:

Default Syntax
Short open Tags
HTML Script embed Tags.

III. Explain in Brief Answer

Question 1.
Write note on HTTP?
Answer:
HTTP:

HTTP HyperText Transfer Protocol.
HTTP is the underlying protocol used by the World Wide Web.
This protocol defines how messages are formatted and transmitted.
The actions taken by web servers and browsers in response to various commands.

Question 2.
Draw a diagram for client server Architecture model?
Answer:

Question 3.
Explain short open tags?
Answer:
Short open Tags:
The Short open Tags begins with “<?” and closes with But admin user has to enable Short style tags settings in php.ini file on the server.

Question 4.
Write note on var-dump function?
Answer:
Var_dump:

The var_dump( ) function is used to dump information about a variable.
This function displays structured information such as type and value of the given variable.
Arrays and objects are explored recursively with values indented to show structure.

Question 5.
Explain resources with examples?
Answer:
Resources
Resource is a specific variable, it has a reference to an external resource. These variables hold specific handlers to handle files and database connections in respective PHP program.
<?php
// Open a file for reading
Shandle = fopen(“note.txt”, “r”);
var_dump($handle);
echo “<br>”;
// Connect to MySQL database server with
default setting
Slink = mysql_connect(“localhost”, “root”, “”);
var_dump(Slink);
?>

Question 6.
Write note on different types of Increment and decrement operators with example?
Increment and Decrement Operators:
Answer:
Increment and decrement operators are used to perform the task of increasing or decreasing variable’s value. This operator is mostly used during iterations in the program logics.

IV. Explain in detail.

Question 1.
Explain different client server Architecture model?
Answer:
Client Server Architecture:
Model Client server architecture is classified into three types, as follows

Single Tier Architecture
Two Tier Architecture
N/Multi/Three tire architecture

1. Single Tier Architecture:
This architecture is used for the server, accessed by client. The client application runs inside the server machine itself. This acts as a single layer interaction as shown in Figure.

2. Two Tier Architecture:
This architecture is used for the server, accessed by client as two layer interactions. Such as Client layer in tire one and server layer in tire Two.

3. Multi/Three Tier Architecture:
This architecture is used for the server, accessed by client through more than one layer interaction. The programmer could decide the count of business logic layers according to the software requirement that is the reason this model is also known as Multi Three Tire Architecture.

Most of the server side scripting languages are working on any one the client server architecture model. Webserver is software which is running in server hardware. It takes the responsibilities for compilation and execution of server side scripting languages.

Question 2.
Explain different types of PHP syntax?
Answer:
Three types of PHP Syntax are available. They are as follows

Default Syntax
Short open Tags
HTML Script embed Tags

1. Default Syntax:
The default Syntax begins with “<?php” and closes with “?>”.

2. Short open Tags:
The Short open Tags begins with “<?” and closes with “?>”. But admin user has to enable Short style tags settings in php.ini file on the server.

3. HTML Script embed Tags:
HTML Script embed Tags looks just like HTML scripts tags. The syntax is shown in Figure.

The above syntax is created and saved in a file with extension of .php. This .php file is ready to execute from Webserver and generate response to client machine.

Question 3.
Explain important features of PHP?
Answer:

PHP is an Open Source
PHP is a Case Sensitive
PHP is a Simplicity Program language
PHP is a Efficiency Program language
PHP is a Platform Independent Program language
PHP is a Security Program language
PHP is a Flexibility Program language
PHP is a Real-Time Access Monitoring Program language

Samacheer Kalvi 10th Social Science Model Question Paper 4 English Medium

Leave a Comment / Class 10 / By Prasanna

Students can Download Samacheer Kalvi 10th Social Science Model Question Paper 4 English Medium Pdf, Samacheer Kalvi 10th Social Science Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamil Nadu Samacheer Kalvi 10th Social Science Model Question Paper 4 English Medium

General Instructions:

The question paper comprises of four parts
You are to attempt all the questions in each part. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III, and IV are to be attempted separately.
Question numbers 1 to 14 in Part I are Multiple Choice Questions of one mark each.
These are to be answered by writing the correct answer along with the corresponding option code and the corresponding answer
Question numbers 15 to 28 in Part II are of two marks each. Any one question should be answered compulsorily.
Question numbers 29 to 42 in Part III are of five marks each. Any one question should be answered compulsorily.
Question numbers 43 to 44 in Part IV are of Eight marks each. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 100

Part – I

Answer all the questions. Choose the correct answer [14 × 1 = 14]

Question 1.
Which country was expelled from the League of Nations for attacking Finland?
(a) Germany
(b) Russia
(c) Italy
(d) France
Answer:
(b) Russia

Question 2.
Which part of the world disliked dollar imperialism?
(a) Europe
(b) Latin America
(c) India
(d) China
Answer:
(b) Latin America

Question 3.
Whose voice was Rast Goftar?
(a) Parsi Movement
(b) Aligarh Movement
(c) Ramakrishna Mission
(d) Dravida Mahajana Sabha
Answer:
(a) Parsi Movement

Question 4.
Where was Sivasubramanianar executed?
(a) Kayathar
(b) Nagalapuram
(c) Virupachi
(d) Panchalamkurichi
Answer:
(b) Nagalapuram

Question 5.
…………………….founded Adi Dravida Mahajana Sabha in 1893.
(a) Rettaimalai Srinivasan
(b) B. R. Ambedkar
(c) Rajaji
(d) M. C. Rajah
Answer:
(a) Rettaimalai Srinivasan

Question 6.
……………………. River is known as “Sorrow of Bihar”.
(a) Narmada
(b) Godavari
(c) Kosi
(d) Damodar
Answer:
(c) Kosi

Question 7.
The longest dam in the world is …………………….
(a) Mettur dam
(b) Kosi dam
(c) Hirakud dam
(d) Bhakra-Nangal dam
Answer:
(c) Hirakud dam

Question 8.
The famous Sindri Fertilizer Plant is located in …………………….
(a) Jharkhand
(b) Bihar
(c) Rajasthan
(d) Visakhapatnam
Answer:
(a) Jharkhand

Question 9.
The district with largest mangrove forest cover in Tamil Nadu is …………………….
(a) Ramanathapuram
(b) Nagapattinam
(c) Cuddalore
(d) Theni
Answer:
(c) Cuddalore

Question 10.
A major hydro-electric power project of Tamil Nadu is …………………….
(a) Mettur
(b) Papanasam
(c) Sathanur
(d) Thungabhadra
Answer:
(a) Mettur

Question 11.
Find the odd one out.
(a) Right to Equality
(b) Right against Exploitation
(c) Right to Property
(d) Cultural and Educational Rights
Answer:
(c) Right to Property

Question 12.
Which article of Indian constitution directs to adopt foreign policy?
(a) Article 50
(b) Article 51
(c) Article 52
(d) Article 53
Answer:
(b) Article 51

Question 13.
Primary sector consist of …………………….
(a) Agriculture
(b) Automobiles
(c) Trade
(d) Banking
Answer:
(a) Agriculture

Question 14.
Pump sets and motors are produced mostly in…………………….
(a) Salem
(b) Coimbatore
(c) Chennai
(d) Dharmapuri
Answer:
(b) Coimbatore

Part – II

Answer any 10 questions. Question No. 28 is compulsory. [10 x 2 = 20]

Question 15.
Discuss the importance of Ottawa Economic Summit.
Answer:

Bilateral trade treaties between Britain and the member states of the British Empire were signed at an economic summit in Ottawa in 1932.
In this summit the participants (including India) agreed to give preference to imperial (British) over non-imperial goods.

Question 16.
What do you know of Baghdad Pact?
Answer:

In 1955, Turkey, Iraq, Great Britain, Pakistan and Iran signed a pact known as Baghdad Pact.
In 1958, the United States joined the organisation and therefore it came to be known as the Central Treaty Organisation. The treaty was open to any Arab nation desiring peace and security in the region.

Question 17.
Write about the Kanpur Massacre of 1857.
Answer:

The Siege of Cawnpur was a key episode in the Indian rebellion of 1857.
The besieged Company forces and civilians in Cawnpur (now Kanpur) were unprepared for an extended siege and surrendered to rebel forces under Nana Sahib, in return for a safe passage to Allahabad.
However under ambiguous circumstances, their evacuation from Cawnpur turned into a massacre, and most of the men were killed.

Question 18.
Highlight the contribution of Caldwell for the cause of South Indian languages.
Answer:

In 1816, F.W. Ellis formulated the theory that the South Indian languages belonged to a separate family which was unrelated to the Indo-Aryan family of languages.
Robert Caldwell expanded this argument in a book titled, A comparative Grammar of the Dravidian or South Indian Family of languages, in 1856.
He established a close affinity between the Dravidian languages in contrast with Sanskrit and also established the antiquity of Tamil.

Question 19.
Give the importance of IST.
Answer:

To avoid the confusion of time in different states of India. One meridian is taken to have a uniform time for a whole country.
Therefore 80° 30’ E has been chosen as the Standard Meridian of India which is almost passing from the centre of India.

Question 20.
What is Migration? State its types.
Answer:
It is the movement of people across regions and territories.

Internal migration and
international migration.

Question 21.
List out the districts of Tamil Nadu which are partly/fully located on Eastern and
Western Ghats separately.
Answer:
Eastern Ghats:
Parangimalai, Chennai, Javadhu hills, Vellore, Salem, Sirumalai, Dindigul, Thiruvannamalai,
Bhubaneswar, Namakkal, Perambalur.
Western Ghats:
Kanyakumari, Tirunelveli, Theni, Coimbatore, Nilgiri.

Question 22.
Why is Coimbatore called the Manchester of Tamil Nadu?
Answer:

Maximum units are concentrated in and around Coimbatore region. For this region it is known as the “Manchester of South India”.
It is known as such because of presence of more than 25,000 small, medium, large scale industries and textile mills.

Question 23.
What is meant by Citizenship?
Answer:
Citizenship is the status of a person recognized under the custom or law as being a legal member of a sovereign state or belonging to a nation.

Question 24.
Explain India’s nuclear policy.
Answer:
Indian nuclear programme in 1974 and 1998 is only done for strategic purposes. The two themes of India’s nuclear doctrine are

No first use
Credible minimum deterrence

It has decided not to use nuclear power for ‘offensive purposes’ and would never use against any non-nuclear state.

Question 25.
What is per capita income.
Answer:

Per capita income or PCI is an indicator to show the living standard of people in a country.
It is obtained by dividing the National Income by the population of a country.

Question 26.
Short note: The Dutch in South India.
Answer:

The Dutch undertook several voyages from 1596 and formed the Dutch East India Company in 1602.
In 1605, Admiral Van der Hagen established Dutch factory at Masulipatnam and Pettapoli, Devanampatinam.
In 1610, upon negotiating with the king of Chandragiri, found another factory at Pulicut. Pulicut was the headquarters of the Dutch in India.

Question 27.
What are the types of tax? Give example.
Answer:
(i) J.S. Mili defines a direct tax as “one which is demanded from the very persons who it is intended or desired should pay it.” Some direct taxes are income tax, wealth tax and corporation tax.

(ii) If the burden of the tax can be shifted to others, it is an indirect tax. The impact is on one person while the incidence is on the another person. Therefore, in the case of indirect taxes, the tax payer is not the tax bearer. Some indirect taxes are stamp duty, entertainment tax, excise duty and goods and service tax (GST).

Question 28.
State the uses of Magnesium.
Answer:

It is an important minerals used for making iron and steel and serves as basic raw material
for alloying.
It is also used in manufacturing bleaching powder, insecticides, paints and batteries.

Part – III

Answer any 10 questions. Question No. 42 is compulsory. [10 x 5 = 50]

Question 29.
Fill in the blanks:
(i) The first woman legislator in India was …………………….
(ii) is the Tamil Nadu state animal which is found in …………………….
(iii) India conducted its first nuclear test at…………………….
(iv) …………………….is fondly called as “Little Japan”.
(v) Sathya Gnana Sabai was established by …………………….
Answers
(i) Mutthu Lakshmi Reddy
(ii) Nilgiri Tahr, Nilgiri hills
(iii) Pokhrah
(iv) Sivakasi
(v) Vallalar

Question 30.
Match the following:

Answers:

Question 31.
Match the following:

Answers:

Question 32.
(a) Distinguish between
(i) Himadri and Himachal.
(ii) Alluvial Soil and Black Soil.
Answer:
(a) (i) Himadri and Himachal :

The Northern most range is known as the Great or Inner Himalayas or the Himadri.
It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres.
It contains all the prominent Himalayan peaks Mt. Everest (8,848 m) and Kanchenjunga (8,586 m).
The core of this part of Himalayas is composed of granite.
It is perennially snow bound and a number of glaciers descend from this range.

Himadri Himachal :

Below Himadri is the most rugged mountain system and is known as Himachal or Lesser Himalayas.
The ranges are mainly composed of highly compressed and altered rocks.
Pir Panjal range forms the longest and the most important range. The Dhaula Dhar and the Mahabharat ranges are also prominent ones.
This range consists of the famous valley of Kashmir, the Kangra and Kullu valley in Himachal Pradesh.
This region is well Known for its hill stations.

(ii) Alluvial Soil and Black Soil.
Alluvial Soil :

It is formed from sediments deposited by rivers.
It is rich in potash.
It has moisture retention capacity.
It is formed along the river course, food, plains, delta and coastal plains.
It is suitable for the cultivation of paddy, wheat and sugarcane.
It is found in punjab, Haryana, UP, Bihar and west bengal. Mahanadi, Godavari, Krishna, Kaveri rivers deposit alluvial soil along their courses.

Black Soil :

It is formed from the weathering of igneous rocks.
It is rich in lime, iron, potash, alumina calcium and magnesium carbonates.
It has high moisture retention capacity.
It is found in the valleys of the Godavari, Krishna, Narmada and Tapti.
It is suitable for the cultivation of cotton, jowar and millets.
It is largely found in the Deccan trap

(b) Give reason: North Indian Rivers are Perennial.
Answer:
Most of the North Indian Rivers are perennial. It means that they have water throughout the year. These rivers receive water from rain as well as from melted snow from the lofty mountains.

Question 33.
Explain the course of the Russian Revolution under the leadership of Lenin.
Answer:

Lenin was in Switzerland when the revolution broke out in Russia. He wanted to continue revolution.
His slogan of “All power to the Soviets” soon won over the workers’ leaders. Devastated by war time shortages, the people were attracted by the slogan of‘Bread, Peace and Land’.
In October Lenin persuaded the Bolshevik Central Committee to decide on immediate revolution. Trotsky prepared a detailed plan.
On 7 November the key government buildings, including the Winter Palace, the Prime Minister’s headquarters, were seized by armed factory workers and revolutionary troops
On 8 November 1917a new Communist government was in office in Russia. Its head this time was Lenin. The Bolshevik Party was renamed the Russian Communist Party.

Question 34.
Write an account on the role played by the 19th century reformers towards the course of women.
Answer:
Several social reformers emerged during the 19th century India who played a big role towards the cause of women:
(i) Raja Rammohun Roy was deeply concerned with the preventing customs of sati, child marriage and polygamy. He advocated the rights of widows to remarry. He wanted polygamy to end. He raised voice against Sati system and forced the Governor-General William Bentinck to abolish this social evil in 1829. He condemned the subjugation of women and opposed the prevailing ideas that women were inferior to men. He strongly advocated education for women.

(ii) Ishwar Chandra Vidyasagar was lead against the burning of widows. He supported the idea of widow remarriage. He played a leading role in promoting education of girls and helped them in setting up a number of schools. He dedicated his entire life for the betterment of the child widows of the Hindu society. He led a movement that resulted in the widows’ Remarriage Reform Act of 1856.

(iii) Jyotiba Phule worked for the cause of women. He opposed child marriage and supported widow remarriage, which was prohibited particularly for the uplift of the depressed classes and women. Jyotiba opened orphanages and homes for widows.

(iv) Swami Dayanand Saraswati said that the prohibition of widow remarriage had no scriptural sanction.

(v) Reformers like R.C. Bhandarkar and Justice Mahadev Govind Ranade devoted themselves to activities such as widow remarriage and improvement of women and depressed classes. M.G. Ranade founded the widow Remarriage Association in 1861.

Question 35.
Write an account on the major iron and steel industries of India.
Answer:
1. Mineral based industries:

The major minerals based industry of our country is the iron and steel industry.
It is a key or basic industry and lays the foundation for other industries.
These industries form the economic backbone of a country.

2. Location of Iron and Steel Industries:
Most of our country’s major iron and steel industries are located in the Chotanagpur plateau region.

3. Distribution of Iron and Steel Industries:
India has 11 integrated steel plant and 150 mini steel plants and a large number of rolling and re-rolling mills.

(i) Tata Iron and Steel Company [TISCO]: In 1911, Tata Iron and Steel Company was set up at Jamshedpur. Its major products are Pig Iron and Crude steel.

(ii) Indian Iron and Steel Company [IISCO]: The Steel plant at Kulti, Bumpur and Hirapur were integrated and the Indian iron and steel company was set up at Bumpur in 1972.

(iii) Visweshwaraya Iron Steel Ltd(VISL): Visweshwaraya Iron Steel Limited was set up in 1923 at Bhadravati in Karnataka. Its major products are alloy and sponge steel.

(iv) (a) Hindustan Steel Limited (HSL) – Bhilai: It is located in Durg district of Chattisgarh. It started its production in 1957. Its major products are Railway Equipment and shipbuilding.
(b) Hindustan Steel Limited (HSL) – Rourkela: It was established in 1965 in Odisha. Its major products include hot and cold rolled sheets, Galvanized sheets and electrical plates.
(c) Hindustan Steel Limited (HSL) – Durgapur: It was established in 1959 in Durgapur of West Bengal. Its major products are alloy,steel, constmction materials and railway equipments.
(d) Hindustan Steel Limited (HSL) – Bokaro: It is situated in the Hazaribagh district of Jharkhand. It started its operation in 1972. Its major products are sludge and slog.

(v) Salem Steel Ltd: It is located at salem in Tamil Nadu. It started its production in 1982. The major products are stainless steel.

(vi) Vijayanagar Steel Plant: The Vijayanagar Steel Plant has been set up at Tomagal in Karnataka. It started its production in 1994. The major products are flat steel and long steel.

(vii) The Visakhapatnam Steel Plant(VSP): It started its operation in 1981 at Visakhapatnam in Andhra pradesh. Its major products are Hot metal.

4. Mini Steel Plants:

Mini steel plants are decentralized secondary units with capacity ranging from 10,000 tonnes to 5 lakh tonnes per year.
They produce mild steel, alloy steel and stainless steel.
Most of the mini steel plants are located in areas far away from the major steel plants so that they can meet the local demands.

Question 36.
Explain the different modes of transport available in Tamil Nadu.
Answer:
Roadways:
The State has a total road length of 167,000 km, In which 60,628km are maintained by state Highways Department. It ranks second in India with a share of over 20% in total road projects under operation in the Public-Private Partnership (PPP) model.

Railways:

Tamil Nadu has a well-developed rail network as part of Southern Railway, headquartered at Chennai.
The present Southern Railway network extends over a large area of India’s southern peninsula, covering Tamil Nadu, Kerala, Puducherry, minor portions of Karnataka and Andhra Pradesh.
Tamil Nadu has a total railway track length of 6,693 km with 690 railway stations in the state.
The system connects it with most of the major cities in India.
Main rail junctions in the state include Chennai, Coimbatore, Erode, Madurai, Salem, Tiruchirappalli and Tirunelveli.
Chennai has a well-established suburban railway network, a Mass Rapid Transport System (MRTS) and is currently developing a Metro system, with its first underground stretch in operation since May 2017.

Airways:
Tamil Nadu has four major international airports. Chennai International Airport is currently the third largest airport in India after Mumbai and Delhi.

Water ways:
Tamil Nadu has 3 major ports. They are Chennai, Ennore and Tuticorin. It has an intermediate port at Nagapattinam and 15 minor ports. Ennore intermediate port was recently converted as a major port and handles the major coal and ore traffics in Tamil Nadu.

Question 37.
Explain the salient features of the constitution of India.
Answer:
Here are the salient features of the Indian Constitution.

It is the lengthiest of all the written Constitutions of the world.
It is partly rigid and partly flexible.
It establishes a federal system of Government.
It establishes the Parliamentary systems not only at the Centre but also in the States.
It provides an independent judiciary.
It makes India as a secular state.
It introduces Universal Adult Franchise and accords the right to vote to all citizens above 18 years of age without any discrimination.
It provides single citizenship.
It makes special provisions for minorities, SCs, STs, etc.

Question 38.
Trace the reason for the formation of BRICS and write its objectives.
Answer:
Reason for the formation of BRICS To be an alternative to World Bank and IMF to challenge U.S. supremacy.
To provide self-owned and self-managed organisations to carry out developmental and economical plans in its member nations.

Objectives of BRICS :

To achieve regional development
It acts as a bridge between developed and developing countries .
To contribute extensively to development of humanity
To establish a more equitable and fair world
Boost intra BRICS trade in their local currencies to increase trade cooperation and cope with the current international financial crisis.
To promote the technological information exchange among the member states
To enhance inclusive economic growth that will lead to an increase in the creation of jobs, fight against poverty and accelerate the economic transformation of members.

Question 39.
Explain the trade and traders in South India.
Answer:

Southern Indian trade guilds were formed by merchants in order to organise and expand their trading activities. Trade guilds became channels through which Indian culture was exported to other lands.
South Indian trade was dominated by the Cholas and it replaced the Pallavas.
In the year 1053 AD (CE) the Kalinga Traders brought red coloured stone for trade and also cotton textile to Southeast Asia.
Several trade guilds operated in medieval Southern India such as the Gatrigas, Nakaras, Ayyavole, Gavaras etc. The Nakaras and Gavaras met only in the temple premises.
Several European traders also arrived in South India such as the Portuguese, Dutch, Danes, French and the British. These traders established their companies / factories and strengthened their root in the Indian soil.

Question 40.
Write are the important characteristics of successful industrial clusters?
Answer:
The following are the chief characteristics of a successful cluster.

geographical proximity of small and medium enterprises (SMEs)
sectoral specialisation
close inter-firm collaboration
inter-firm competition based on innovation
a socio-cultural identity, which facilitates trust .
multi-skilled workforce
active self-help organisations, and
supportive regional and municipal governments.

Question 41.
Draw a time line for the following:
Write any five important events between 1855-1905
Answer:

Question 42.
Mark the following places on the world map.
(i) San Francisco
(ii) Hawai Island
(iii) Moscow
(iv) Hiroshima
(v) Nagasaki
Answer:

Part – IV

Answer both questions. [2 x 8 = 16]

Question 43.
(a) Cold War
(i) Name the two military blocs that emerged in the Post-World War II.
(ii) Who coined the term “Cold War” and who used it first?
(iii) What was the response of Soviet Russia to the formation of NATO?
(iv) What was the context in which Warsaw Pact was dissolved?
Answer:
(a) Cold War:
(i) (1) The United States (2) The Soviet Union
(ii) The term ‘Cold War’was first coined by the English Writer George Orwell in 1945. Bernard Baruch, the US presidental adviser, was the first to use it in a speech.
(iii) The Soviet Russia did not welcome the formation of the NATO. To counter it, Soviet Union organised the Soviet-bloc countries for a united military actions under the Warsaw Pact in 1955.
(iv) The Warsaw Pact was dissolved in 1991 following the fall of the Berlin Wall and the reunification of Germany.

(b) Periyar E. V. R
(i) When did Periyar found Dravidar Kazhagam?
(ii) What were the newspapers and Journals run by Periyar?
(iii) Why was Periyar known as Vaikom hero?
(iv) Which was the most important work of Periyar?
Answer:
(b) Periyar E. V. R:
(i) Periyar found Dravidar Kazhagam in 1944.

(ii) The newspapers and journals started by Periyar were – Kudi Arasu, Revolt, Puratchi,
Paguththarivu and Viduthalai.

(iii) In Vaikom, people protested against the practice of no access to the temples by the lower caste people. After the local leaders were arrest’d Periyar led the Temple Entry Movement and was imprisoned. So, people hailed him as Vaikom Virar or hero of Vaikom.

(iv) Right from 1929, when the Self-respect Conferences began to voice its concern over the plight of women, Periyar had been emphasising women’s right to divorce and property. Periyar’s most important work on this subject is Why the Woman is Enslaved?

[OR]

Question 43.
(c) Causes of the Second World War.
(i) Name the treaty signed by Japan, Italy and Germany.
(ii) Mention some of the ideologies that emerged after the First World War.
(iii) What was the policy followed by the statesmen of the major world powers?
(iv) What did Hitler violate?
Answer:
(c) Causes of the Second World War:
(i) Italy – Germany – Japan signed the Rome – Berlin – Tokyo Axis treaty.
(ii) Democracy, Communism, Fascism and Nazism.
(iii) The statesmen of the major world powers followed the policy of appeasement.
(,iv) He violated the Munich Pact.

(d) Language agitation before Indian Independence
(i) Name the movements that helped to galvanise the Tamil language.
(ii) Highlight the contribution of Abraham Pandithar for the cause of Tamil music.
(iii) What was seen as a threat to Tamil language and music?
(iv) Who introduced Hindi as a compulsory subject in schools?
Answer:
(d) Language agitation before Indian Independence:
(i) Maraimalai Adigal’s Pure Tamil Movement, the language reforms of Periyar and Tamil Isai Movement.
(ii) Abraham Pandithar systematically studied the history of Tamil music and attempted to reconstruct ancient Tamil musical system. He founded the Tanjore Sangitha Vidya Mahajana Sangam in 1912 which became the kernel of the Tamil Isai Movement or Tamil Music Movement.
(iii) The implementation of Hindi as a compulsory language in Tamil Nadu, at various points of time, was seen as a threat to Tamil language and culture.
(iv) C. Rajagopalachari introduced Hindi as a compulsory subject in schools.

Question 44.
Mark the following places on the given outline map of India.
(i) Deccan Plateau
(ii) Western Ghats
(iii) South west monsoon
(iv) Agasthiyamalai biosphere reserve
(v) Jute growing area
(vi) Damodar dam
(vii) Anyone iron ore producing region .
(viii) Tuticorin
Answer:

[OR]

Mark the following places on the given outline map of Tamil Nadu:
(i) River Vaigai
(ii) Laterite soil region
(iii) Tropical Evergreen forest region
(iv) Chennai
(v) Cotton growing area
(vi) Vellore
(vii) Karaikal seaport
(viii) Amaravathi dam
Answer:

Map for Q. 44
(i) Deccan Plateau
(ii) Western Ghats
(iii) South west monsoon
(iv) Agasthiyamalai biosphere reserve
(v) Jute growing area
(vi) Damodar dam
(vii) Anyone iron ore producing region
(viii) Tuticorin
Answer:

Map for Q. 44
(i) River Vaigai
(ii) Laterite soil region
(iii) Tropical Evergreen forest region
(v) Chennai
(v) Cotton growing area
(vi) Vellore
(vii) Karaikal seaport
(viii) Amaravathi dam
Answer:

Samacheer Kalvi 10th Science Model Question Paper 5 English Medium

Leave a Comment / Class 10 / By Prasanna

Students can Download Samacheer Kalvi 10th Science Model Question Paper 5 English Medium Pdf, Samacheer Kalvi 10th Science Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamil Nadu Samacheer Kalvi 10th Science Model Question Paper 5 English Medium

General Instructions:

The question paper comprises of four parts
You are to attempt all the questions in each part. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III and IV are to be attempted separately.
Question numbers 1 to 12 in Part I are Multiple Choice Questions of one mark each.
These are to be answered by writing the correct answer along with the corresponding option code.
Question numbers 13 to 22 in Part II are of two marks each. Any one question should be answered compulsorily.
Question numbers 23 to 32 in Part III are of four marks each. Any one question should be answered compulsorily.
Question numbers 33 to 35 in Part IV are of seven marks each. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 75

Part – I

(i) Answer all the questions. [12 × 1 = 12]
(ii) Choose the most suitable answer and write the code with the corresponding answer.

Question 1.
To project the rockets which of the following principle(s) is /(are) required?
(a) Newton’s third law of motion
(b) Newton’s law of gravitation
(c) Law of conservation of linear momentum
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)

Question 2.
Kilowatt hour is the unit of _______.
(a) resistivity
(b) conductivity
(c) electrical energy
(d) electrical power
Answer:
(c) electrical energy

Question 3.
_______ element emits its radiation spontaneously.
(a) Ni
(b) Pb
(c)Pt
(d) u
Answer:
(d) u

Question 4.
Which of the following is a triatomic molecule?
(a) Glucose
(b) Helium
(c) Carbon-di-oxide
(d) Hydrogen
Answer:
(c) Carbon-di-oxide

Question 5.
________ is an important metal to form amalgam.
(a) Ag
(b) Hg
(c) Mg
(d) Al
Answer:
(b) Hg

Question 6.
The component present in lesser amount, in a solution is called _______.
(a) solute
(b) solvent
(c) solution
(d) colloid
Answer:
(a) solute

Question 7.
A patient with blood group ‘O’ was injured in an accident and has blood loss. Which blood group the doctor should effectively use _______ for transfusion.
(a) O group
(b) AB group
(c) A or B group
(d) All blood group
Answer:
(a) O group

Question 8.
Excessive consumption of alcohol leads to _______.
(a) Loss of memory
(b) Cirrhosis of liver
(c) State of hallucination
(d) Suppression of brain function
Answer:
(b) Cirrhosis of liver

Question 9.
_______ is formed during anaerobic respiration.
(a) Carbohydrate
(b) Ethyl alcohol
(c) Acetyl CoA
(d) Pyruvate
Answer:
(b) Ethyl alcohol

Question 10.
Casparian strips are present in the _____ of the root.
(a) Cortex
(b) Pith
(c) Pericycle
(d) Endodermis
Answer:
(d) Endodermis

Question 11.
The soft finely stratified sedimentary rock refer to _______.
(a) Shale
(b) Petroleum
(c) Methane
(d) Coal
Answer:
(a) Shale

Question 12.
All files are stored in the _______.
(a) Folder
(b) Box
(c) Paint
(d) Scanner
Answer:
(a) Folder

Part – II

Answer any seven questions. (Q.No: 22 is compulsory) [7 × 2 = 14]

Question 13.
State Newton’s second law.
Answer:
“The force acting on a body is directly proportional to the rate of change of linear momentum of the body and the change in momentum takes place in the direction of the force”.

Question 14.
What are the caused of “Myopia”?
Answer:
Myopia, also known as short sightedness, occurs due to the lengthening of eye ball. With this defect, nearby objects can be seen clearly but distance objects cannot be seen clearly.

Question 15.
What is the minimum distance needed for an echo?
Answer:

The minimum distance required to hear an echo is 1/20^th part of the magnitude of the velocity of sound in air.
If you consider the velocity of sound as 344 ms^-1, the minimum distance required to hear an echo is 17.2 m.

Question 16.
Why does the reaction rate of a reaction increase on raising the temperature?
Answer:
On increasing temperature heat is supplied to the reactant. This energy breaks more bonds and thus speed up the chemical reaction. Foods kept at room temperature spoils faster than that kept in the refrigerator.

Question 17.
Differentiate soaps and detergents.
Answer:

Soaps	Detergents
1. It is a sodium salt of long chain fatty acids.	1. It is a sodium salt of sulphonic acids.
2. Its effectiveness is reduced when used in hard water.	2. It is effective even in hard water.
3. Soaps are biodegradable.	3. Most of the detergents are non-biodegradable.

Question 18.
Write the dental formula of rabbit.
Answer:
Dental formula is (I $\frac{2}{1}$, C$\frac{0}{0}$, PM $\frac{2}{1}$, M $\frac{2}{1}$) in Rabbit, which is written as $\frac{2033}{1023}$
I – Incisors, C – Canine, PM – Premolar and M-molar.

Question 19.
What is bolting? How can it be induced artificially?
Answer:
Sudden shoot elongation followed by flowering is known as bolting. Artifically bolting can be induced on rosette plants by the treatment of Gibberellins.

Question 20.
Identify the parts A,B,C & D?

Answer:
A – Exine
B – Intine
C – Generative cell
D – Vegetative nucleus

Question 21.
How can you determine the age of the fossils?
Answer:
The age of fossils is determined by radioactive elements present in it. They may be carbon, uranium, lead or potassium. By radio active carbon (C¹⁴) dating method, carbon consumption of animals and plants stops after death and since then, only the decaying process of C¹⁴ occurs continuously. The time passed since death of a plant or animal can be calculated by measuring the amount of C¹⁴ present in their body.

Question 22.
A charge of 10 coulomb flows through a bulb in 5 second. What is the current through the bulb?
Answer:
Given : Q = 10 C
t = 5 s
I = $\frac{Q}{t}=\frac{10}{5}$
I = 2 A

Part – III

Answer any seven questions (Q.No: 32 is compulsory) [7 × 4 = 28]

Question 23.
State and prove the law of conservation of linear momentum.
Answer:
(i) There is no change in the linear momentum of a system of bodies as long as no net external force acts on them.
(ii) Let us prove the law of conservation of linear momentum with the following illustration:

(iii) Let two bodies A and B having masses m₁ and m₂ move with initial velocity u₁ and u₂ in a straight line.
(iv) Let the velocity of the first body be higher than that of the second body. i.e., u₁ > u₂.
(v) During an interval of time t second, they tend to have a collision. After the impact, both of them move along the same straight line with a velocity v₁ and v₂ respectively.
Force on body B due to A, F_B = $\frac{m_{2}\left[v_{2}-u_{2}\right]}{t}$
Force on body A due to B, F_A = $\frac{m_{1}\left[v_{1}-u_{1}\right]}{t}$

By Newton’s III law of motion,
Action force = Reaction force
F_A = -F_B
$\frac{m_{1}\left[v_{1}-u_{1}\right]}{t}=-\frac{m_{2}\left[v_{2}-u_{2}\right]}{t}$
m₁v₁ – m₁u₁ = -m₂v₂ + m₂u₂
m₁v₁ + m₂v₂ = m₁u₁ + m₂u₂

The above equation confirms in the absence of an external force, the algebraic sum of the momentum after collision is numerically equal to the algebraic sum of the momentum before collision. Hence file law of conservation linear momentum is proved.

Question 24.
(i) Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F.
Answer:
Ray diagram for object placed between F and 2F

(ii) Define one calorie.
Answer:
One calorie is defined as the amount of heat energy required to rise the temperature of 1 gram of water through 1°C.

Question 25.
(i) How many electrons are passing per second in a circuit in which there is a current of 5A?
Answer:
Current I = 5 A
time (t) = 1 second
Charge of electron e = 1.6 × 10^-19 C

(ii) Mention two cases in which there is no Doppler effect in sound?
Answer:

When source (S) and listener (L) both are at rest.
When S and L move in such a way that distance between them remains constant.
When source S and L are moving in mutually perpendicular directions.
If the source is situated at the center of the circle along which the listener is moving.

Question 26.
Derive the relationship between Relative molecular mass and Vapour density.
Answer:
(а) The Relative Molecular Mass of a gas or vapour is the ratio between the mass of one molecule of the gas or vapour to mass of one atom of Hydrogen.

(b) Vapour density is the ratio of the mass of a certain volume of a gas or vapour, to the mass of an equal volume of hydrogen, measured under the same conditions of temperature and pressure.

(c) According to Avogadro’s law, equal volumes of all gases contain equal number of molecules.
Thus, let the number of molecules in one volume = n, then

(f) By comparing the definition of relative molecular mass Mid vapour density we can write as follows.

(g) By substituting the relative molecular mass value in vapour density definition, we get Vapour density (V.D.) = Relative molecular mass / 2
2 × vapour density = Relative molecular mass of a gas

Question 27.
How is metal corrosion prevented?
Answer:
Methods of preventing corrosion:
1. Alloying: The metals can be alloyed to prevent the process of corrosion.
E.g: Stainless Steel

2. Surface Coating: It involves application of a protective coating over the metal. It is of the
following types:
(a) Galvanization: It is the process of coating zinc on iron sheets by using electric current.
(b) Electroplating: It is a method of coating one metal over another metal by passing electric current.
(c) Anodizing: It is an electrochemical process that converts the metal surface into a decorative, durable and corrosion resistant. Aluminium is widely used for anodizing process.
(d) Cathodic Protection: It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called Sacrificial metal to act as anode ensuring cathodic protection.

Question 28.
With a neat labelled diagram explain the structure of a neuron.
Answer:

A typical neuron consists of 3 parts: Cyton, Dendrites and Axon.
(1) Cyton:

It has a central nucleus with the abundant cytoplasm called neuroplasm.
The cytoplasm has large granular body called Nissel’s granules
Other cell organelles like mitochondria, ribosomes, lysosomes, and endoplasmic reticulum are present.
Several neurofibrils in the cytoplasm help in transmission of nerve impulses to and form the cell body.

(2) Dendrites:

These are the numerous branched cytoplasmic processes, that project from the surface of the cell body.
They conduct nerve impulses, towards the cyton.
The branched projections increase the surface area for receiving the signals from other nerve cells.

(3) Axon:

It is a single, elongated, slender projection.
The end of axon terminates as fine branches, which terminate into knob like swellings called synaptic knob.
The plasma membrane of axon is called axolemma,
The cytoplasm of axon is called axoplasm.
Axon carries impulses away from the cyton.
The protective sheath around the axon is myelin sheath
The myelin sheath breaks at intervals by depression called Nodes of Ranvier. It acts as insulator and ensures rapid transmission of nerve impulses.
The junction between two neuron is called synapsis.

Question 29.
(i) Read the following content and answer the questions below:
Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in F₁ generation are then cross-bred to produce F₂ generation of pea plants.
(a) What do the plants of F₁ generation look like?
(b) What is the ratio of tall plants to dwarf plants in F₂ generation?
(c) Which type of plants were missing in F₁ generation but reappeared in F₂ generation?
Answer:
(a) In F₁ generation, all plants are tall (Tt)
(b) In F₂ generation the ratio of tall plants to dwarf plant is 3:1. i.e., 3 tall and 1 dwarf
Three types of plants were obtained
Tall homozygous : TT – 1
Tall heterozygous : Tt – 2
Dwarf homozygous : tt -1

(c) Dwarf plants were missing on F₁ but reappeared in F₂ generation.

(ii) Why is the sino-atrial node Called the pacemaker of heart?
Answer:
Sino-atrial node acts as the ‘pacemaker’ of the heart because it is capable of initiating impulse which can stimulate the heart muscles to contract.

Question 30.
Differentiate the following:
(a) Monocot root and Dicot root
(b) Aerobic and Anaerobic respiration (a) Monocot root and Dicot root
Answer:

Monocot Root	Dicot Root
1. Number of Xylem Polyarch	1. Tetrach
2. Cambium is absent.	2. Cambium is present during secondary growth
3. Secondary growth absent.	3. Secondary growth present.
4. Pith present	4. Pith absent

(b) Aerobic and Anaerobic respiration
Answer:

Aerobic respiration	Anaerobic respiration
1. Occur in the presence of oxygen.	1. Occurs in the absense of oxygen
2. Carbon dioxide, water and ATP are produced.	2. Lactic acid, Ethanol and ATP are produced.
3. It occurs in most plant and animals	3. It occurs in plants and bacteria

Question 31.
(i) What precautions can be taken for preventing heart disease?
(ii) Name two maize hybrids rich in amino acid lysine.
Answer:
(i) Prevention for preventing heart disease

Reduction in the intake of calories, low saturated fat, cholesterol rich food, low carbohydrates and common salt.
Increase in the intake of fibre diet, fruits and vegetables, protein, minerals and vitamins.
Regular exercise, walking and yoga are essential for body weight maintenance.
Avoid alcohol consumption, Psychotrophic drugs and smoking.

(ii) Protina, shakt and Rathna are lysine rich maize hybrids, which are developed in India.

Question 32.
(i) Write the features of nuclear fission and nuclear fusion.
Answer:
Nuclear Fission

The process of breaking up of a heavy nucleus into two smaller nuclei is called ‘nuclear fission’.
Can be performed at room temperature.
Alpha, beta and gamma radiations are emitted.
Fission leads to emission of gamma radiation. This triggers the mutation in the human gene and causes genetic transform diseases.

Nuclear Fusion:

Nuclear fusion is the combination of two lighter nuclei to form a heavier nucleus.
Extremely high temperature and pressure is needed.
Alpha rays, positrons, and neutrinos are emitted.
Only light and heat energy is emitted.

(ii) Calculate the pH of 0.01 M HNO₃?
Answer:
pH = -log[H⁺]
= -log₁₀^-2
= (-2) (- log₁₀¹⁰)
= 2 × 1.00
pH = 2

Part – IV

(1) Answer all the questions. [3 × 7 = 21]
(2) Each question carries seven marks.
(3) Draw diagram wherever necessary.

Question 33.
(i) State Boyle’s law.
Answer:
When the temperature of a gas is kept constant, the volume of a fixed mass of gas is inversely proportional to its pressure.
P ∝ 1/V

(ii) Explain the experiment of measuring the real and apparent expansion of a liquid with a neat diagram.
Answer:
(1) To start with, the liquid whose real and apparent expansion is to be determined is poured in a container up to a level. Mark this level as L₁.
(2) Now, heat the container and the liquid using a burner as shown in the figure Initially, the container receives the thermal energy and it expands.
(3) As a result, the volume of the liquid appears to have reduced. Mark this reduced level of liquid as L₂.

On further heating, the thermal energy supplied to the liquid through the container results in the expansion of the liquid. Hence, the level of liquid rises to L₃. Now, the difference between the levels L₁ and L₃ is called as apparent expansion, and the difference between the levels L₂ and L₃ is called real expansion. The real expansion is always more than that of apparent expansion.
Real expansion = L₃ – L₂
Apparent expansion = L₃ – L₁

[OR]

(b) (i) A source of sound is moving with a velocity of 50 ms^-1 towards a stationary listener. The listener measures the frequency of the source as 1000 Hz. what will be the apparent frequency of the source when it is moving away from the listener after crossing him? (velocity of sound in the medium is 330 ms^-1)
Answer:
When the source is moving towards the stationary listener, the expression for apparent frequency is

The actual frequency of the sound is 848.48 Hz. When the source is moving away from the stationary listener, the expression for apparent frequency is

(ii) Calculate the velocity of a moving body of mass 5 kg whose linear momentum is 2 kg ms^-1.
Answer:
Linear momentum = mass × velocity
Velocity = Linear momentum / mass
v = 2.5 / 5 = 0.5 ms^-1

Question 34.
(a) (i) Calculate the mass of 1.51 x 10^-23 molecule of H₂O.
Answer:

(ii) Calculate the moles of 46 g sodium.
Answer:
46 g of sodium
Atomic mass of sodium = 23
Mass of sodium = 46
No. of moles = $\frac{\text { mass }}{\text { atomic mass }}=\frac{46}{23}$
= 2 mole of sodium

(iii) Calculate the number of molecules present in the 36 g water.
Answer:
H₂O → = (1 × 2) + (1 × 16)
= 2 + 16
H₂O = 18 g

= 12.046 × 10²³ atoms
36 g water contains → 12.046 x 10²³ atoms

[OR]

(b) (i) Write notes on various factors affecting solubility.
Answer:
Factors affecting solubility: There are three main factors which govern die solubility of solute. They are:

Nature of the solute arid solvent
Temperature
Pressure

(1) Nature of the solute and solvent: The nature of the solute and solvent plays an important role in solubility. Although water dissolves an enormous variety of substances, both ionic and covalent, it does not dissolve everything.

The phrase that scientists often use when predicting solubility is “like dissolves like.” This expression means that dissolving occurs when similarities exist between the solvent and the solute. For example: Common salt is a polar compound and dissolves readily in polar solvent like water.

Non-polar compounds are soluble in non-polar solvents. For example, Fat dissolved in ether. But non-polar compounds, do not dissolve in polar solvents; polar compounds do not dissolve in non-polar solvents.

(2) Effect of Temperature:
Solubility of Solids in Liquid: Generally, solubility of a solid solute in a liquid solvent increases with increase in temperature. For example, a greater amount of sugar will dissolve in warm water than in cold water.
In endothermic process, solubility increases with increase in temperature.
In exothermic process, solubility decreases with increase in temperature.

Solubility of Gases in liquid : Solubility of gases in liquid decrease with increase in temperature. Generally, water contains dissolved oxygen. When water is boiled, the solubility of oxygen in water decreases, so oxygen escapes in the form of bubbles.

Aquatic animals live more in cold regions because, more amount of dissolved oxygen is present in the water of cold regions. This shows that the solubility of oxygen in water is more at low temperatures.

(3) Effect of Pressure: Effect of pressure is observed only in the case of solubility of a gas in a liquid. When the pressure is increased, the solubility of a gas in liquid increases.

The common examples for solubility of gases in liquids are carbonated beverages, i.e. soft drinks, household cleaners containing aqueous solution of ammonia, formalinaqueous solution of fonnaldehyde, etc.

Question 35.
(a) (i) Why are thyroid hormones referred as personality hormone?
(ii) Define triple fusion?
(iii) Enumerate the importance of forests?
Answer:
(i) Thyroid hormones is essential for normal physical, mental and personality development. Hence it is called as personality honnone.
(ii) The fusion involving two polar nucleus and a sperm nucleus, that occurs in double fertilization in a seed plant and results in the formation of endosperm, is called the triple fusion.
(iii) Importance of forests.

Forests are the important component of our environment and are dominated by microorganisms, flowering plants, shrubs, climbers and dense trees.
Forests provide a vast habitat for wild animals.
Forests help for the economic development of our country.
Forests are the source for a wide range of renewable natural resource.
Forests provide wood, food, fodder, fibre and medicine.
They act as carbon sink, regulate climatic conditions, increase rainfall and reduce global warming.
Forests protect wild life and also acts as catchment for water conservation.
They prevent natural hazards like floods and landslides
They play a vital role in maintaining the ecological balance.

[OR]

(b) (i) List out any three parasitic adaptations in leech.
(ii) Natural selection is a driving force for evolution-How?
Answer:
(i) Parasitic adaptation of leech:

Anterior and Posterior ends of the body are provided with suckers by which the animal attaches itself to the body of the host.
The three Jaws, inside the mouth, causes a painless Y – shaped wound in the skin of the host.
The salivary glands produce Hirudin, which does not allow the blood to coagulate. So, the continuous supply of blood is maintained.

(ii) Darwin published his observations under the name “origin of species”. It elaborates on the theory of natural selection for evolutionary transformation. The principles of Darwinism tells that natural selection is a driving force for evolution.

1. Overproduction: Living beings have the ability to reproduce and have the capacity to multiply in a geometrical manner.

2. Struggle for existence: Due to overproduction a geometric ratio of increase in population occurs. The space to live and food available for the organisms remain the same. This creates a competition among the organisms, for food and space, leading to struggle.

The competition may be among the individuals of the same species (Intraspecific struggle).
Competition between the organisms of different species living together (Interspecific struggle).
Natural conditions like extreme heat or cold drought and floods can affect the existence of organisms (Environmental struggle).

3. Variations:
Small variations are important for evolution. According to Darwin, favourable variations are useful to the organisms and unfavourable variations are harmful or useless to the organisms.

4. Survival of the fittest or Natural selection:
During the struggle for existence, the organisms which can overcome the challenging situation,survive and adapt to the surrounding environment. Organisms, which are unable to face the challenges, are unfit to survive and disappear. The process of selection of organisms with favourable variation is called as Natural selection.

5. Origin of species:
According to Darwin, new species originates by the gradual accumulation of favourable variations for a number of generations.

Samacheer Kalvi 11th Accountancy Solutions Chapter 9 Rectification of Errors

Tamilnadu Samacheer Kalvi 11th Accountancy Solutions Chapter 9 Rectification of Errors

Samacheer Kalvi 11th Accountancy Rectification of Errors Text Book Back Questions and Answers

I. Multiple Choice Questions
Choose the Correct Answer

Question 1.
Error of principle arises when ………………
(a) There is complete omission of a transaction
(b) There is partial omission of a transaction
(c) Distinction is not made between capital and revenue items
(d) There are wrong postings and wrong castings
Answer:
(c) Distinction is not made between capital and revenue items

Question 2.
Errors not affecting the agreement of trial balance are ………………
(a) Errors of principle
(b) Errors of overcasting
(c) Errors of undercasting
(d) Errors of partial omission
Answer:
(a) Errors of principle

Question 3.
The difference in trial balance is taken to ………………
(a) The capital account
(b) The trading account
(c) The suspense account
(d) The profit and loss account
Answer:
(c) The suspense account

Question 4.
A transaction not recorded at all is known as an error of ………………
(a) Principle
(b) Complete omission
(c) Partial omission
(d) Duplication
Answer:
(b) Complete omission

Question 5.
Wages paid for installation of machinery wrongly debited to wages account is an errs of ………………
(a) Partial omission
(b) Principle
(c) Complete omission
(d) Duplication
Answer:
(b) Principle

Question 6.
Which of the following errors will not affect the trial balance?
(a) Wrong balancing of an account
(b) Posting an amount in the wrong account but on the correct side
(c) Wrong totalling of an account
(d) Carried forward wrong amount in a ledger account
Answer:
(b) Posting an amount in the wrong account but on the correct side

Question 7.
Goods returned by Senguttuvan were taken into stock, but no entry was passed in the books. While rectifying this error, which of the following accounts should be debited?
(a) Senguttuvan account
(b) Sales returns account
(c) Returns outward account
(d) Purchases returns account
Answer:
(b) Sales returns account

Question 8.
A credit purchase of furniture from Athiyaman was debited to purchases account. Which of the following accounts should be debited while rectifying this error?
(a) Purchases account
(b) Athiyaman account
(c) Furniture account
(d) None of these
Answer:
(c) Furniture account

Question 9.
The total of purchases book was overcast. Which of the following accounts should be debited in the rectifying journal entry?
(a) Purchases account
(b) Suspense account
(c) Creditor account
(d) None of the above
Answer:
(b) Suspense account

Question 10.
Which of the following errors will be rectified using suspense account?
(a) Purchases returns book was undercast by ₹ 100
(b) Goods returned by Narendran was not recorded in the books
(c) Goods returned by Akila ₹ 900 was recorded in the sales returns book as ₹ 90
(d) A credit sale of goods to Ravivarman was not entered in the sales book
Answer:
(a) Purchases returns book was undercast by ₹ 100

II. Very Short Answer Questions

Question 1.
What is meant by rectification of errors?
Answer:
Correction of errors in the books of accounts is not done by erasing, rewriting or striking the figures which are incorrect. Correcting the errors that has occured is called Rectification.

Question 2.
What is meant by error of principle?
Answer:
It means the mistake committed in the application of fundamental accounting principles in recording a transaction in the books of accounts.

Question 3.
What is meant by error of partial omission?
Answer:
When the accountant has failed to record a part of the transaction, it is known as error of partial omission. This error usually occurs in posting. This error affects only one account.

Question 4.
What is meant by error of complete omission?
Answer:
It means the failure to record a transaction in the journal or subsidiary book or failure to post both the aspects in ledger. This error affects two or more accounts.

Question 5.
What are compensating errors?
Answer:
The errors that make up for each other or neutralize each other are known as compensating errors. These errors may occur in related or unrelated accounts. Thus, excess debit or credit in one account may be compensated by excess credit or debit in some other account. These are also known as offsetting errors.

III. Short Answer Questions

Question 1.
Write a note on error of principle by giving an example.
Answer:
It means the mistake committed in the application of fundamental accounting principles in recording a transaction in the books of accounts.
Example:
Entering the purchase of an asset in the purchases book. Machinery purchased on credit for ₹ 10,000 by M/s. Anbarasi garments manufacturing company entered in the purchases book.

Question 2.
Write a note on suspense account.
Answer:
When the trial balance does not tally, the amount of difference is placed to the debit (when the total of the credit column is higher than the debit column) or credit (when the total of the debit column is higher than the credit column) to a temporary account is known as ‘suspense account’.

Question 3.
What are the errors not disclosed by a trial balance?
Answer:
Certain errors will not affect the agreement of trial balance. Though such errors occur in the books of accounts, the total of debit and credit balance will be the same. The trial balance will tally. Errors of complete omission, error of principle, compensating error, wrong entry in the subsidiary books are not disclosed by the trial balance.

Question 4.
What are the errors disclosed by a trial balance?
Answer:
Certain errors affect the agreement of trial balance. If such errors have occurred in the books of accounts, the total of debit and credit balances will not be the same. The trial balance will not tally. Error of partial omission and error of commission affect the agreement of trial balance.

Question 5.
Write a note on one – sided errors and two – sided errors.
Answer:

One – sided errors: When preparing the trial’balance, if the total of debit balances and credit balances are not the same, there is disagreement of trial balance.
Two – sided errors: Rectification of two – sided errors at the time of preparing the trial balance is just similar to that of their rectification before preparation of trial balance.

IV. Exercises

Question 1.
State the account/s affected in each of the following errors: (2 marks)
(a) Goods purchased on credit from Saranya for ₹ 150 was posted to the debit side of her account.
(b) The total of purchases book ₹ 4,500 was posted twice.
Answer:
(a) Purchases from Saranya should have been posted to the credit of Saranya’s A/c, but it has been debited. Hence, credit Saranya’s A/c with double the amount i.e., Rs. 300.
(b) Credit the Purchases A/c.

Question 2.
State the account/s affected in each of the following errors: (2 marks)
(a) Goods sold to Vasu on credit for ₹ 1,000 was not recorded in the sales book.
(b) The total of sales book ₹ 2,500 was posted twice.
Answer:
(a)

(b) Debit the Sales A/c

Question 3.
Rectify the following errors discovered before the preparation of the trial balance: (2 marks)
(a) Sales book was undercast by ₹ 100
(b) Purchases returns book was overcast by ₹ 200
Answer:
(a) Sales account should be credited with ₹ 100
(b) Purchases returns account should be debited with ₹ 200

Question 4.
Rectify the following errors before the preparation of trial balance: (3 marks)
(a) Returns outward book was undercast by ₹ 2,000
(b) Returns inward book total was taken as ₹ 15,000 instead of ₹ 14,000
(c) The total of the purchases account was carried forward ₹ 100 less.
Answer:
(a) Returns outward Account should be credited with ₹ 2,000
(b) Sales returns account should be credited with ₹ 1,000
(c) Purchases account should be debited with ₹ 100

Question 5.
Rectify the following errors assuming that the trial balance is yet to be prepared: (5 marks)
(a) Sales book was undercast by ₹ 400
(b) Sales returns book was overcast by ₹ 500
(c) Purchases book was undercast by ₹ 600
(d) Purchases returns book was overcast by ₹ 700
(e) Bills receivable book was undercast by ₹ 800
Answer:
(a) Sales account should be credited with ₹ 400
(b) Sales returns account should be credited with ₹ 500
(c) Purchases account should be debited with ₹ 600
(d) Purchases returns account should be debited with ₹ 700
(e) Bills receivable account should be debited with ₹ 800

Question 6.
Rectify the following errors before preparing trial balance: (5 marks)
(a) The total of purchases book was carried forward ₹ 90 less.
(b) The total of purchases book was carried forward ₹ 180 more
(c) The total of sales book was carried forward ₹ 270 less.
(d) The total of sales returns book was carried forward ₹ 360 more.
(e) The total of purchases returns book was carried forward ₹ 450 less.
Answer:
(a) Purchases account should be debited ₹ 90
(b) Purchases account should be credited ₹ 180
(c) Sales account should be credited ₹ 270
(d) Sales returns account should be credited with ₹ 360
(e) Purchases returns account should be credited with ₹ 450

Question 7.
The following errors were located by the accountant before preparation of trial balance. Rectify them. (5 marks)
(a) The total of the discount column of ₹ 1,100 on the debit side of the cash book was not yet posted.
(b) The total of the discount column on the credit side of the cash book was undercast by ₹ 500.
(c) Purchased goods from Anbuchelvan on credit for ₹ 700 was posted to the debit side of his account.
(d) Sale of goods to Ponmukil on credit for ₹ 78 was posted to her account as ₹ 87.
(e) The total of sales returns book of ₹ 550 was posted twice.
Answer:

Question 8.
The accountant of a firm located the following errors before preparing the trial balance. Rectify them. (5 marks)
(a) Machinery purchased for ₹ 3,000 was debited to purchases account.
(b) Interest received ₹ 200 was credited to commission account.
(c) An amount of ₹ 1,000 paid to Tamilselvan as salary was debited to his personal account.
(d) Old furniture sold for ₹ 300 was credited to sales account.
(e) Goods worth ₹ 800 purchased from Soundarapandian on credit was not recorded in the books of accounts.
Answer:
Rectifying Journal

Question 9.
Rectify the following errors which were located before preparing the trial balance. (5 marks)
(a) Wages paid ₹ 2,000 for the erection of machinery was debited to wages account.
(b) Sales returns book was short totalled by ₹ 1,000.
(c) Goods purchased for ₹ 200 was posted as ₹ 2,000 to purchases account.
(d) The sales book was overcast by ₹ 1,500.
(e) Cash paid to Mukil ₹ 2,800 which was debited to Akhil’s account as ? 2,000.
Answer:
Rectifying Journal

Question 10.
Rectify the following errors which were located at the time of preparing the trial balance: (5 marks)
(a) The total of the discount column on the debit side of the cash book of ₹ 225 was posted twice.
(b) Goods of the value of ₹ 75 returned by Ponnarasan was not posted to his account.
(c) Cash received from Yazhini ₹ 1,000 was not posted.
(d) Interest received ₹ 300 has not been posted.
(e) Rent paid ₹ 100 was posted to rent account as ₹ 10.
Answer:

Question 11.
The following errors were located at the time of preparing trial balance. Rectify them. (5 marks)
(a) A personal expense of the proprietor ₹ 200 was debited to travelling expenses account.
(b) Goods of ₹ 400 purchased from Ramesh on credit was wrongly credited to Ganesh’s account.
(c) An amount of ₹ 500 paid as salaries to Mathi was debited to his personal account.
(d) An amount of ₹ 2,700 paid for extension of the building was debited to repairs account.
(e) A credit sale of goods of ₹ 700 on credit to Mekala was posted to Krishnan’s account.
Answer:

Question 12.
Rectify the following journal entries. (5 marks)

Answer:

Question 13.
Rectify the following errors discovered after the preparation of the trial balance: (5 marks)
(a) Rent paid was carried forward to the next page ₹ 500 short.
(b) Wages paid was carried forward ₹ 250 excess.
Answer:
(a) Rent account is to be debited with ₹ 500.
(b) Wages account is to be credited with ₹ 250.

Question 14.
Rectify the following errors after preparation of trial balance: (5 marks)
(a) Salary paid to Ram ₹ 1,000 was wrongly debited to his personal account.
(b) A credit sale of goods to Balu for ₹ 450 was debited to Balan.
Answer:

Question 15.
Pass necessary journal entries to rectify the following errors located after the preparation of trial balance: (5 marks)
(a) Sales book was undercast by ₹ 1,000.
(b) An amount of ₹ 500 paid for wages was wrongly posted to machinery Account.
Answer:
(a) Sales account should be credited ₹ 1,000.
(b)

Question 16.
Give journal entries to rectify the following errors discovered after the preparation of trial balance: (5 marks)
(a) Purchases book was overcast by ₹ 10,000.
(b) Repairs to furniture of ₹ 500 was debited to furniture account.
(c) A credit sale of goods to Akilnilavan for ₹ 456 was credited to his account as ₹ 654.
Answer:
(a) Purchases account should be credited ₹ 10,000.

Question 17.
Rectify the following errors located after the preparation of trial balance: (5 marks)
(a) Purchases book was undercast by ₹ 900.
(b) Sale of old furniture for ₹ 1,000 was credited to sales account.
(c) Purchase of goods from Arul for ₹ 1,500 on credit was not recorded in the books.
Answer:
(a) Purchases account should be debited with ₹ 900.

Question 18.
The following errors were located after the preparation of trial balance. Pass journal entries to rectify them. Assume that there exists a suspense account. (5 marks)
(a) The total of sales book was undercast by ₹ 350.
(b) The total of the discount column on the debit side of cash book ₹ 420 was not posted.
(c) The total of one page of the purchases book of ₹ 5,353 was carried forward to the next page as ₹ 5,533.
(d) Salaries ₹ 2,400 was posted as ₹ 24,000.
(e) Purchase of goods from Sembiyanmadevi on credit for ₹ 180 was posted to her account as ₹ 1,800.
Answer:
Rectifying Journals

Question 19.
Rectify the following errors assuming that, the trial balance is already prepared and the difference was placed to suspense account: (5 marks)
(a) Sales book was undercast by ₹ 250.
(b) Purchases book was undercast by ₹ 120.
(c) Sales book was overcast by ₹ 130.
(d) Bills receivable book was undercast by ₹ 75.
(e) Purchases book was overcast by ₹ 35.
Answer:
(a) Sales account should be credited ₹ 250.
(b) Purchases account should be debited ₹ 120.
(c) Sales account should be debited ₹ 130.
(d) Bills receivable account should be debited ₹ 75.
(e) Purchases account should be credited ₹ 35.

Question 20.
The following errors were located after the preparation of trial balance. The difference in trial balance has been taken to suspense account. Rectify them. (5 marks)
(a) The total of purchases book was carried forward ₹ 70 less.
(b) The total of sales book was carried forward ₹ 340 more.
(c) The total of purchases book was carried forward ₹ 150 more.
(d) The total of sales book was carried forward ₹ 200 less.
(e) The total of purchases returns book was carried forward ₹ 350 less.
Answer:
Rectifying Journals

Question 21.
The following errors were located by the accountant after the preparation of trial balance. There exists a suspense account. Rectify them. (5 marks)
(a) The total of the discount column of ₹ 1,180 on the debit side of the cash book was not posted.
(b) Purchase of goods from Arivuchelvan on credit for ₹ 600 was posted to the debit side of his account.
(c) The total of the discount column on the credit side of the cash book was undercast by ₹ 400.
(d) The total of sales returns book of ₹ 570 was posted twice.
(e) Sold goods to Mukil on credit for ₹ 87 was posted to her account as ₹ 78.
Answer:

Question 22.
The accountant of a firm located the following errors after preparing the trial balance. Rectify them assuming that there is a suspense account. (5 marks)
(a) Machinery purchased for ₹ 3,500 was debited to purchases account.
(b) ₹ 1,800 paid to Raina as salary was debited to his personal account.
(c) Interest received ₹ 200 was credited to commission account.
(d) Goods worth ₹ 1,800 purchased from Amudhanila on credit was not recorded in the books of accounts.
(e) Used furniture sold for ₹ 350 was credited to sales account.
Answer:

Question 23.
The book – keeper of a firm found that the trial balance was out by ₹ 922 (excess credit). He placed the amount in the suspense account and subsequently found the following errors: (5 marks)
(a) The total of discount column on the credit side of the cash book ₹ 78 was not posted in the ledger.
(b) The total of purchases book was short by ₹ 1,000.
(c) A credit sale of goods to Natarajan for ₹ 375 was entered in the sales book as ₹ 735.
(d) A credit sale of goods to Mekala for ₹ 700 was entered in the purchases book. You are required to give rectification entries and prepare suspense account.
Answer:

Suspense Account

Question 24.
The books of Raman did not agree. The accountant placed the difference of ₹ 1,270 to the debit of suspense account. Rectify the following errors and prepare the suspense account:
(a) Goods taken by the proprietor for his personal use ₹ 75 was not entered in the books.
(b) A credit sale of goods to Shanmugam for ₹ 430 was credited to his account as ₹ 340.
(c) A purchase of goods on credit for ₹ 400 from Vivek was entered in the sales book. However, Vivek’s account was correctly credited.
(d) The total of the purchases returns book ₹ 300 was not posted.
Answer:

Suspense Account

Textbook Case Study Solved

Question 1.
Rameela, a class 11 student, visited one of her relative’s furniture shop. She met the accountant of the shop. He was busy with preparing final accounts. At that time, one of the staff approached the accountant with a list of errors found in ledger postings. Rameela asked the accountant, in a surprised tone, “Is it possible to rectify the errors before preparing the final accounts?” The accountant replied, “Yes, it is!” final accounts?” The accountant replied,
“Yes, it is!”
Rameela was curious to analyse the errors. She found the following:

Furniture sold on credit to Siva and company for ₹ 12,000 was debited to Sam and company;
Rent paid ₹ 2,500, was debited to rent account as ₹ 250.
The total of purchase journal was undercast by ₹ 1,000.
A sales invoice for ₹ 2,000, completely omitted from the books.
Stationery bought for ₹ 250, was posted to purchases account.

Can you help Rameela to identify and rectify the errors?
Answer:

Samacheer Kalvi 11th Accountancy Rectification of Errors Additional Questions and Answers

I. Multiple Choice Questions
Choose the correct answer

Question 1.
The errors can be classified into ……………… types.
(a) One
(b) Two
(c) Three
(d) Four
Answer:
(d) Four

Question 2.
When the accountant has failed to record a part of the transaction is known as ………………
(a) Error of partial omission
(b) Error of commission
(c) Compensating errors
(d) Error of principle
Answer:
(a) Error of partial omission

Question 3.
The errors that make up for each other or neutralise each other are known as ………………
(a) Errors of commission
(b) Errors of principle
(c) Errors of omission
(d) Compensating errors
Answer:
(d) Compensating errors

Question 4.
The total of salary account is carried forward ₹ 1200 excess ……………….
(a) Errors in carry forward
(b) Errors in posting
(c) Errors in casting
(d) Errors of commission
Answer:
(a) Errors in carry forward

Question 5.
Sales book is undercast by ₹ 100, classify the error
(a) Errors of principle
(b) Errors of commission
(c) Errors in casting
(d) Errors of omission
Answer:
(c) Errors in casting

II. Very Short Answer Questions

Question 1.
What is error of omission?
Answer:
The failure of the accountant to record a transaction or an item in the books of accounts is known as an error of omission. It can be complete omission or partial omission.

Question 2.
What is error of commission?
Answer:
When a transaction is incorrectly recorded, it is known as error of commission. It usually occurs due to lack of concentration or carelessness of the accountant.

Question 3.
What do you mean by errors?
Answer:
Errors means recording or classifying or summarising the accounting transactions wrongly or omissions to record them by a clerk or an accountant unintentionally.

III. Short Answer Questions

Question 1.
What are the types of errors at the stage of journalising?
Answer:

Error of omission
Error of commission
Error of principle

Question 2.
What are the types of errors at the stage of posting?
Answer:
(i) Errors of Omission:
(a) Error of complete omission
(b) Error of partial omission

(ii) Errors of Commission:
(a) Posting to wrong account
(b) Posting of wrong account
(c) Posting to the wrong side

Question 3.
What are the types of errors at the stage of preparing trial balance?
Answer:
(i) Error of Omission
(ii) Error of Commission:

(a) Entering to wrong account
(b) Entering wrong amount
(c) Entering to the wrong side of trial balance, etc.

Samacheer Kalvi 12th Chemistry Solutions Chapter 10 Surface Chemistry

Tamilnadu Samacheer Kalvi 12th Chemistry Solutions Chapter 10 Surface Chemistry

Samacheer Kalvi 12th Chemistry Chapter 10 Surface Chemistry Textual Evaluation Solved

Samacheer Kalvi 12th Chemistry Surface Chemistry Multiple Choice Questions

Question 1.
For freudlich isotherm a graph of log $\frac{x}{m}$ is plotted against log P. The slope of the line and its y – axis intercept respectively corresponds to
(a) $1 / n$, k
(b) log $1 / n$, k
(c) $1 / n$, log k
(d) log $1 / n$, log k
Answer:
(c) $1 / n$, log k
$\frac{x}{m}$ = $\mathrm{k} \cdot \mathrm{p}^{1 / \mathrm{n}}$
log$(\frac{x}{m})$ = log k + $\frac { 1 }{ n }$log p
y = c + mx
m = $\frac { 1 }{ n }$ and c = log k

Question 2.
Which of the following is incorrect for physisorption?
(a) reversible
(b) increases with increase in temperature
(c) low heat of adsorption
(d) increases with increase in surface area
Answer:
(b) increases with increase in temperature
Physisorption is an exothermic process. Hence increase in temperature decreases the physisorption.

Question 3.
Which one of the following characteristics are associated with adsorption?
(a) ∆G and ∆H are negative but ∆S is positive
(b) ∆G and ∆S are negative but ∆H is positive
(c) ∆G is negative but ∆H and ∆S are positive
(d) ∆G. AH and ∆S all are negative.
Answer:
(d) ∆G, ∆H and ∆S all are negative.
Adsorption leads to decrease in randomness (entropy).i.e. ∆S < 0 for the adsorption to occur, ∆G should be – ve. We know that ∆G = ∆H – T∆S if ∆S is – ve, T∆S is + ve. It means that ∆G will become negative only when ∆H is – ve and ∆H > T∆S

Question 4.
Fog is colloidal solution of ……………..
(a) solid in gas
(b) gas in gas
(c) liquid in gas
(d) gas in liquid
Answer:
(c) liquid in gas
dispersion medium-gas, dispersed phase-liquid

Question 5.
Assertion: Coagulation power of Al³⁺ is more than Na.
Reason: greater the valency of the flocculating ion added, greater is its power to cause precipitation
(a) if both assertion and reason are true and reason is the correct explanation of assertion.
(b) if both assertion and reason are true but reason is not the correct explanation of assertion.
(c) assertion is true but reason is false
(d) both assertion and reason are false
Answer:
(a) if both assertion and reason are true and reason is the correct explanation of assertion. (Hardy-Sechuize nile)

Question 6.
Statement: To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified?
(a) It is not true, ferric chloride is a poison.
(b) It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol
(c) It is not true; ferric chloride is ionic and gets into the blood stream.
(d) It is true, coagulation takes place because of formation of negatively charged sol with Cl^–.
Answer:
(b) It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol

Question 7.
Hair cream is …………..
(a) gel
(b) emulsion
(c) solid sol
(d) sol.
Answer:
(b) emulsion
Emulsion dispersed phase, Dispersion medium -liquid

Question 8.
Which one of the following is correctly matched?
(a) Emulsion – Smoke
(b) Gel – butter
(c) foam – Mist
(d) whipped cream – sol
Answer:
(b) Gel – butter

Question 9.
The most effective electrolyte for the coagulation of As₂S₃ Soils
(a) NaCI
(b) Ba(NO₃)₂
(c) K₃[Fe(CN)₆]
(d) AI³⁺
Answer:
(d) AI³⁺
As₂S₃ is a – vely charged colloid. It will be most effectively coagulated by the cation with greater valency. i.e., Al³⁺.

Question 10.
Which one of the is not a surfactant?
(a) CH₃ – (CH₂)₁₅ – N – (CH₃)₂CH₂Br
(b) CH₃ – (CH₂)₁₅ – NH₂
(c) CH₃ – (CH₂)₁₆ – CH₂OSO₂ – Na⁺
(d) OHC – (CH₂)₁₄ – CH₂ – COO^–Na⁺
Answer:
(b) CH₃ – (CH₂)₁₅ – NH₂

Question 11.
The phenomenon observed when a beam of light is passed through a colloidal solution is ………….
(a) Cataphoresis
(b) Electrophoresis
(c) Coagulation
(d) Tyndall effect
Answer:
(d) Tyndall effect-scattering of light

Question 12.
In an electrical field, the particles of a colloidal system move towards cathode. The coagulation of the same sol is studied using K₂SO₄
(i). Na₃PO₄
(ii). K₄[Fe(CN)₆]
(iii). and NaCI
(iv). Their coagulating power should be …………..
(a) II > I >IV > III
(b) III > II > I > IV
(c) I > II > III > IV
(d) none of these
Answer:
(b) III > II > I > IV

Question 13.
Collodion is a 4% solution of which one of the following compounds in alcohol – ether mixture?
(a) Nitroglycerine
(b) Cellulose acetate
(c) Glycoldinitrate
(d) Nitrocellulose
Answer:
(a) Nitrocellulose
pyroxylin (nitro cellulose)

Question 14.
Which one of the following is an example for homogeneous catalysis?
(a) manufacture of ammonia by Haber’s process
(b) manufacture of sulphuric acid by contact process
(c) hydrogenation of oil
(a) Hydrolysis of sucrose in presence of all HCI
Answer:
(a) Hydrolysis of sucrose in presence of all HCl
Both reactant and catalyst are in same phase. i.e. (1)

Question 15.
Match the following.

Answer:
(a) (iv) (i) (ii) (iii)

Question 16.
The coagulation values in millimoles per litre of the electrolytes used for the coagulation of AS₂S₃ are given below
(I) (NaCI) = 52
(II) (BaCl) = 0.69
(III) (MgSO₄) = 0.22
The correct order of their coagulating power is ……….
(a) III > II > I
(b) I > II > III
(c) I >III > II
(d) II > III > I
Answer:
(a) III > II > I
coagulating power ± $\frac{1}{\text { coagulation value }}$

Question 17.
Adsorption of a gas on solid metal surface is spontaneous and exothermic, then ……………
(a) ∆H increases
(b) ∆S increases
(c) ∆G increases
(d) ∆S decreases
Answer:
(a) ∆S decreases – ∆S is -ve

Question 18.
If x is the amount of adsorbate and m is the amount of adsorbent, which of the following relations is not related to adsorption process?
(a) x/m = f(P) at constant T
(b) x/m = f(T) at constant P
(c) P = f(T) at constant x/m
(d) x/m = PT
Answer:
(d) x/m = mPT

Question 19.
On which of the following properties does the coagulating power of an ion depend?
(a) Both magnitude and sign of the charge on the ion.
(b) Size of the ion alone
(c) the magnitude of the charge on the ion alone
(d) the sign of charge on the ion alone.
Answer:
(a) Both magnitude and sign of the charge on the ion.

Question 20.
Match the following.

Answer:
(d) (iv) (iii) (ii) (i)

Samacheer Kalvi 12th Chemistry Surface Chemistry Short Answer Questions

Question 1.
Give two important characteristics of physisorption.
Answer:

Important characteristics of physisorption:

It is reversible
It has low heat of adsorption
It has weak van der Waals forces of attraction with adsorbent.
It increases with increase in pressure.
It forms multi molecular layer.

Question 2.
Differentiate physisorption and chemisorption.
Answer:
Chemical adsorption or Chemisorption or Activated adsorption

It is very slow
It is very specific depends on nature of adsorbent and adsorbate.
chemical adsorption is fast with increase pressure, it can not alter the amount.
When temperature is raised chemisorption first increases and then decreases.
Chemisorption involves transfer of electrons between the adsorbent and adsorbate,
Heat of adsorption is high i.e., from 40 – 400kJ/mole.
Monolayer of the adsorbate is formed.
Adsorption occurs at fixed sites called active centres. It depends on surface area.
Chemisorption involves the formation of activated complex with appreciable activation energy.
Physical adsorption or van der Waals adsorption or Physisorptlon
It is irreversible.

Physical adsorption or van der Waals adsorption or physisorption.

It is instantaneous
It is non-specific
In Physisorption. when pressure increases the amount of adsorption increases.
Physisorption decreases with an increase in temperature.
No transfer of electrons
Heat of adsorption is low in the order of 40 kJ/mole.
Multilayer of the adsorbate is formed on the adsorbent.
It occurs on all sides.
Activation energy is insignificant.
It is reversible.

Question 3.
In the case of chemisorption, why adsorption first increases and then decrease with temperature?
Answer:
1. Chemisorption involves high activation energy so it is also referred to as activated adsorption.

2. It is found in chemisorption that it first increases and then decreases with increase in temperature. When adsorption is plotted, the graph first increases and then decreases with temperature.

3. The initial increase illustrates the requirement of activation of the surface for adsorption is due to fact that the formation of activated complex requires certain energy. But later it decreases at high temperature is due to desorption as the kinetic energy of the adsorbate increases (exothermic nature)

Question 4.
Which will be adsorbed more readily on the surface of charcoal and why; NH₃ or CO₂?
Answer:
1. The gases having low critical temperature are adsorbed slowly, while gases with high critical temperature are adsorbed readily.

2. Among CO₂, and NH₃, NH₃will be more readily adsorbed on the surface of the charcoal. This is because the critical temperature of ammonia gas is quite high than the CO₂. Hence, it easily combines with the materials than the CO₂ whether it is solid, liquid or any gases.

Question 5.
Heat of adsorption is greater for chemisorptions than physisorption. Why?
Answer:
Chemisorption has higher heat of adsorption. because in chemisorption the chemical bonds are much stronger. In adsorbed state the adsorbate is hold on the surface of adsorbent by attractive forces (bond). And chemisorption is irreversible one. Therefore, heat of adsorption is greater for chenil sorptions than physisorption. Chemisorption, heat of adsorption range 40 – 400kJ/mole.

Question 6.
In a coagulation experiment 10 mL of a colloid (X) is mixed with distilled water and 0.1M solution of an electrolyte AB so that the volume is 20 mL. It was found that all solutions containing more than 6.6 mL of AB coagulate with in 5 minutes. What is the flocculation values of AB for sol (X)?
Answer:
A minimum of 6.6mL of AB is required to coagulate the sol. The moles of AB in the sol is
$\frac{6.6 \times 0.01}{20}$ = 0.033 moles
This means that a minimum of 0.033 moles or 0.0033 x 1000 = 3.3 milli moles are required for coagulating one litre of sol. Flocculation value of AB for X = 3.3

Question 7.
Peptising agent is added to convert precipitate into colloidal solution. Explain with an example.
Answer:
1. Ions either positive or negative of peptizing agent (electrolyte) are adsorbed on the particles of precipitate. They repel and hit each other and break the particles of the precipitate into colloidal size.

2. For example, when we add a small volume of very dilute hydrochloric acid solution peptising agent to a fresh precipitate of a silver chloride, it leads to formation of silver chloride colloidal solution,

Question 8.
What happens when a colloidal sol of Fe(OH)₃ and As₂S₃ are mixed?
Answer:
On mixing Fe(OH)₃ positive sol and As₂S₃ negative sol, mutual coagulation occurs which causes precipitation. When these sol got mixed with each other, due to Fe³⁺ and S^2- ions neutralisation of charges will happen and precipitate will be formed.
Fe(OH)₃ + As₂S₃ → Fe₂S₃ + As(OH)₃

Question 9.
What is the difference between sol and a gel?
Answer:
Sol

The liquid state of a colloidal solution is called sol.
The sol does not have a definite structure.
The dispersion medium of the sol may be water.
The sol can be converted to gel by cooling The sol can be easily dehydrated.
The viscosity of the sol is very low.
Sol is categorized into lyophobic and lyophilic sols.
Example: Blood

Gel

The solid or semi-solid state of a colloidal solution is called gel.
The gel possesses honey comb-like structure.
The dispersion medium of gel will be hydrated colloid particles.
The gel can be converted sol by heating.
The gel cannot be dehydrated.
The viscosity of the gel is very high.
There is no such classification of gel.
Example: Fruit jelly, cooked gelatin jelly.

Question 10.
Why are lyophillic colloidal sols are more stable than lyophobic colloidal sol?
Answer:
1. A lyophilic colloidal sols are stable due to the charge and the hydration of sol particles.

2. Lyophilic sols are more stable than lyophobilc sols because they are highly hydrated in the solution. And since more is the hydration more will be its stability.

3. Lyophilic sols are stabilized by electrostatic charge and hydration where as lyophobile sols are only stabilized by charge, so they easily gets coagulated and requires a stabilising agent. Hence, lyophilic sols are more stable than lyophobilc sols.

Question 11.
Addition of Alum purifies water. Why?
Answer:
Purification of drinking water is activated by coagulation of suspended impurities in water using alums containing Al³⁺. That is why we are adding to purify water.

Question 12.
What are the factors which influence the adsorption of a gas on a solid?
Answer:
Factors which influence the adsorption of a gas on a solid is as follows:
1. Nature of the gas:
Easily liquefiable gases such as NH₃, HCl etc are adsorbed to a great extent in comparison to gases such as H₂, O_2, etc. This is because van der Waal’s forces are stronger is easily liquifiable gases.

2. Surface area of the solid:
The greater the surface area of the adsorbent, the greater is the adsorption of gas on the solid surface.

3. Effect of pressure:
Adsorption is a reversible process and is accompanied by a decrease in pressure. Therefore, adsorption increases with an increase in pressure.

4. Effect of temperature:
Adsorption is an exothermic process. Thus in accordance with Le – Chatelier’s principle, the magnitude of adsorption decreases with an increase in temperature.

Question 13.
What are enzymes? Write a brief note on the mechanism of enzyme catalysis.
Answer:
Enzymes are complex protein molecules with three-dimensional structures. They catalyse the chemical reaction in a living organism. They are often present in colloidal state and extremely specific in catalytic action.

Each enzyme produced in a particular living cell can catalyse a particular reaction in the cell. Mechanism of enzyme catalysis: Mechanism of enzyme catalysed reaction is known as lock and key mechanism.
1. Enzymes arc highly specific in their action.

2. This specificity is due to the pressure of active sites. The shape of active site of any given enzyme is like cavity such that only a specific substrate can fit into it.

In the same way a key fits into lock. The specific binding needs the formation of an enzyme-substrate complex which accounts for high specificity of enzyme-catalyzed reactions.

3. Once the proper orientation is attained the substrate molecules react to form the product in two steps.

4. Since the product molecule does not have an affinity for the enzyme they leave the enzyme surface making room for the fresh substrate.

step 1: Formation of the enzyme-substrate complex

Step 2: Dissociation of the enzyme-substrate complex to form product

The rate of the formation of the product depends upon the concentration of ES.

Question 14.
What do you mean by activity and selectivity of catalyst?
Answer:
1. Activity of Catalyst:
The activity of a catalyst is its ability to increase the rate of a particular reaction, Chemisorption is the main factor in deciding the activity of a catalyst. The adsorption of reactants in the catalyst surface should be neither too strong nor too weak. It should just be strong enough to make the catalyst active.

2. Selectivity of the catalyst:
The ability of the catalyst to direct a reaction to yield a particular product is referred to as the selectivity of the catalyst. For example, by using different catalysts, we can get different products for the reaction between H₂ and CO.

Question 15.
Describe some features of catalysis b Zeolites.
Answer:

Zeolites are microporous, crystalline, hydrated aluminosilicates, made of silicon and aluminium tetrahedra.
There are about 50 natural zeolites and 1 50 synthetic zeolites. As silicon is tetravalent and aluminium is trivalent, the zeolite matrix carries an extra negative charge. To balance the negative charge, there are extra framework cations, for example, H⁺ or Na⁺ ions.
Zeolites earring protons are used as solid acids, catalysis and they are extensively used in the petrochemical industry for cracking heavy hydrocarbon fractions into gasoline, diesel, etc.
Zeolites earring Na ions are used as basic catalysis.
One of the most important applications of zeolites is their shape selectivity. In zeolites, the active sites namely protons are lying inside their pores. So, reactions occur only inside the pores of zeolites.

Question 16.
Give three uses of emulsions.
Answer:

The cleansing action of soap is due to emulsions.
It is used in the preparation of vanishing cream.
It is used in the preparation of cold liver oil.

Question 17.
Why does the bleeding stop by rubbing moist alum?
Answer:
Blood is a colloidal sol. When we nib the injured part with moist alum then coagulation of blood takes place. Hence main reason is coagulation, which stops the bleeding. Therefore bleeding stop by rubbing moist alum.

Question 18.
Why is desorption important for a substance to act as good catalyst?
Answer:
Desorption is important for a substance to act as a good catalyst, so that after the reaction, the products found on the surface separate out (desorbed) to create free surface again for other reactant molecules to approach the surface and react. If desorption does not occur then other reactants are left with no space on the surface of the catalyst for adsorption and the reaction will stop.

Question 19.
Comment on the statement: Colloid is not a substance but it is a state of substance.
Answer:
The statement is true. Because the same substance may exist as a colloid under certain conditions and as a crystalloid under certain other conditions. For example. NaCl in water behaves as a crystalloid while in benzene, it behaves as a colloid. Similarly, dilute soap solution behaves

like a crystalloid while concentrated solutions behaves as a colloid. It is the size of the particles which matters. That is the state in which the substance exists. If the size of the particles lies in the range 1 nm to 1oo nm, it is in the colloidal state.

Question 20.
Explain any one method for coagulation
Answer:
The flocculation and setting down of the sol particles is called coagulation. Various method of coagulation are given below:

Addition of electrolytes
Electrophoresis
Mining oppositely charged sols
Boiling.

Addition of electrolytes
A negative ion causes the precipitation of positively charged sol and vice versa. When the valency of ion is high, the precipitation power is increased. For example, the precipitation power of some cations and anions varies in the following order
Al³⁺ > Ba²⁺ > Na⁺, Similarly [Fe(CN)₆]^-3 > SO₄^-2 > Cl^–
The precipitation power of electrolyte is determined by finding the minimum concentration (millimoles/lit) required to cause precipitation of a sol in 2hours. This value is called the flocculation value. The smaller the flocculation value greater will be precipitation.

Question 21.
Write a note on electroosmosis.
Answer:
Electro osmosis:
A sol is electrically neutral. Hence the medium carries an equal but opposite charge to that of dispersed particles. When sol particles are prevented from moving, under the influence of electric field the medium moves in a direction opposite to that of the soil particles. This movement of dispersion medium under the influence of electric potential is called electro-osmosis.

Question 22.
Write a note on catalytic poison
Answer:
Catalytic poison:
Certain substances when added to a catalysed reaction, decreases or completely destroys the activity of catalyst and they are often known as catalytic poisons. For example, In the reaction,
2SO₂ + O₂ → 2SO₃ with a Pt catalyst, the poison is AS₂O₃.
i.e., AS₂O₃ destroys the activity of pt. AS₂O₃ blocks the activity of the catalyst. So, the activity is lost.

Question 23.
Explain the intermediate compound formation theory of catalysis with an example.
Answer:
The intermediate compound formation theory:
A catalyst acts by providing a new path with low energy of activation. in homogeneously catalysed reactions a catalyst may combine with one or more reactant to form an intermediate which reacts with other reactant or decompose to give products and the catalyst is regenerated.

Consider the reactions:
A + B → AB ……………(1)
A + C → AC (intermediate) ………….(2)
C is the catalyst
AC + B → AB + C …………(3)
Activation energies for the reactions (2) and (3) are lowered compared to that of (1). Hence the formation and decomposition of the intermediate accelerate the rate of the reaction.
Example:
The mechanIsm of Fridel crafts reaction is given below

The action of catalyst is explained as follows .

This theory describes,

The specificity of a catalyst.
The increase in the rate of the reaction with increase in the concentration of a catalyst.

Limitations

The intermediate compound theory fails to explain the action of catalytic poison and activators (promoters).
This theory is unable to explain the mechanism of heterogeneous catalysed reactions.

Question 24.
What is the difference between homogenous and hetrogenous catalysis?
Answer:
Hornogenous Catalysis:

In a catalysed reaction the reactants, products and catalyst are present in the same phase.
For example.

Hence NO act as catalyst.
Homogeneous catalysis explained by intermediate compound formation theory.

Heterogeneous Catalysis:

In a reaction, the catalyst is present in a different phase. i.e., catalyst is not present in the same phase as that of reactants and products.
For example.

Hence Pt(s) act as catalyst.
Hetenogeneous catalysis explained by adsorption theory.

Question 25.
Describe adsorption theory of catalysis.
Answer:
Adsorption theory:
Langmuir explained the action of catalyst in heterogeneous catalysed reactions based on adsorption. The reactant molecules are adsorbed on the catalyst surfaces, so this can also he called as contaçt catalysis.

According to this theory, the reactants arc adsorbed on the catalyst surface to form an activated complex which subsequently decomposes and gives the product. The various steps involved in a heterogeneous catalysed rcacton arc given as follows:

Reactant molecules diffuse from bulk to the catalyst surface.
The reactant molecules are adsorbed on the surface of the catalyst.
The adsorbed reactant molecules are activated and form activated complex which is decomposed to form the products.
The product molecules are desorbed.
The product diffuse away from the surface of the catalyst.

Advantages of adsorption theory:
The adsorption theory explains the following .
1. Increase in the activity of a catalyst by increasing the surface area. Increase in the surface area of metals and metal oxides by reducing the particle size increases the rate of the reaction.

2. The action of catalytic poison occurs when the poison blocks the active centres of the catalyst.

3. A promoter or activator increases the number of active centres on the surfaces.

Samacheer Kalvi 12th Chemistry Surface Chemistry Additional Questions

Samacheer Kalvi 12th Chemistry Surface Chemistry 1 mark Questions and Answers

I. Choose the correct answer and write it. Answers are in bold it.

Question 1.
Which one of the following is used to absorb colourants from sugar?
(a) Silica gel
(b) Magnesia
(c) Charcoal
(d) Alumina
Answer:
(c) Charcoal

Question 2.
Silica gel is usually adsorbed………….
(a) Colourants
(b) Hydrogen
(c) Liquid Helium
(d) Water
Answer:
(d) Water

Question 3.
Which one of the following is called adsorbate?
(a) Charcoal
(b) Silica gel
(c) Ammonia
(d) Magnesia
Answer:
(c) Ammonia

Question 4.
Which of the following can act as adsorbent?
(a) Silica gel
(b) Ammonia
(c) Colourants
(d) Water
Answer:
(a) Silica gel

Question 5.
The surface of separation of two phases where the concentration of adsorbed molecule is high is known as …………..
(a) adsorbate
(b) adsorbent
(c) interface
(d) residual phase
Answer:
(c) interface

Question 6.
Consider the following statement.
(i) High adsorption is the result of high surface area of the adsorbent.
(ii) The process of removing an adsorbed substance is called absorption.
(iii) Adsorbed substance is called an adsorbate.

Which of the above statement is / are not correct?
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (ii) only
(d) (iii) only
Answer:
(c) (ii) only

Question 7.
Which metal cannot act as adsorbent?
(a) Pt
(b) Ag
(c) Pd
(d) Al
Answer:
(d) Al

Question 8.
Consider the following statements.
(i) Adsorption is spontaneous process.
(ii) Adsorption is always accompanied by an increase in free energy.
(iii) Adsorption is an endothermic reaction.

Which of the above statement is/are not correct?
(a) (i) only
(b) (ii) & (iii)
(c) (ii) & (i)
(d) (i) only
Answer:
(b) (ii) & (iii)

Question 9.
Absorption and adsorption if simultaneously occurs, it is called ……………
(a) occlusion
(b) sorption
(c) desorption
(d) dissolution
Answer:
(b) sorption

Questioin 10.
The process of sorption of gases on the metal surface is called ……………
(a) Desorption
(b) Dissolution
(c) Occlusion
(d) Condensation
Answer:
(c) Occlusion

Question 11.
When gas molecules are held to the surface by the formation of the chemical bond the heat energy released is nearly equal to
(a) 40 kJ/mole
(b) 800 kJ/mole
(c) 400 kJ/mole
(d) 4 kJ/mole
Answer:
(c) 400 kJ/mole

Question 12.
Which of the following is physical adsorption?
(a) Adsorption of H₂ on nickel
(b) Friedel crafts reaction
(c) Synthesis of SO₃ in the presence of NO
(d) Corrosion of iron
Answer:
(a) Adsorption of H₂ on nickel

Question 13.
Which one of the following is chemical adsorption?
(a) Adsorption of O₂ on tungsten
(b) Adsorption of ethyl alcohol vapours on nickel
(c) Adsorption of N₂ on mica
(d) Rusting of iron
Answer:
(d) Rusting of iron

Question 14.
Which of the following occurs at low temperatures?
(a) Adsorption of O₂ on tun gsen
(b) Adsorption of N₂ on mica
(c) Adsorption of ethyl alcohol vapours on nickel
(d) Adsorption of H₂ on nickel
Answer:
(b) Adsorption of N₂ on mica

Question 15.
Consider the following statements:
(i) Chemical adsorption is an instantaneous process
(ii) Multilayer of the adsorbate is formed on the adsorbent
(iii) Chemisorption involves the formation of the activated complex.

Which of the above statement is/are not correct?
(a) (i) & (ii)
(b) (iii) only
(c) (i) only
(d) (ii) only
Answer:
(a) (i) & (ii)

Question 16.
Consider the following statements:
(i) In chemisorption, heat of adsorption is high
(ii) Monolayer of the adsorbate is formed during chemisorption
(iii) Physisorption increases with an increase in temperature.

Which of the above statement is/are not correct’?
(a) (i) & (ii)
(b) (iii) only
(c) (ii) only
(d) (i) only
Answer:
(b) (iii) only

Question 17.
The extent of surface adsorption does not depend on
(a) Nature of the adsorbent
(b) Pressure
(c) Temperature
(d) Density
Answer:
(d) Density

Question 18.
Which of the following gases is not a permanent gas?
(a) NH₃
(b) H₂
(c) N₂
(d) O₂
Answer:
(a) NH₃

Question 19.
Which of the following is liquefiable gas?
(a) SO₂
(b) H₂
(c) N₂
(d) O₂
Answer:
(a) SO₂

Question 20.
Which one of the following is a permanent gas?
(a) NH₃
(b) SO₃
(c) N₂
(d) CO₂
Answer:
(c) N₂

Question 21.
Consider the following statements.
(i) When pressure increases, the amount of physisorplion also increases.
(ii) Permanent gases like H₂, N₂and O₂ cannot be liquefied easily.
(iii) Lesser is the surface area, higher is the amount adsorbed.

Which of the above statement is/are correct?
(a) (i) & (ii)
(b) (iii) only
(c) (ii) only
(d) (i) only
Answer:
(a) (i) & (ii)

Question 22.
Which one of the following is used in blast furnace for drying air?
(a) Activated charcoal
(b) Silica gel
(c) Alumina
(d) Permutit
Answer:
(b) Silica gel

Question 23.
Which is employed in the softening of hardwater to absorb Ca²⁺ and Mg²⁺ ions?
(a) Alumina
(b) Silica gel
(c) Permutit
(d) Charcoal
Answer:
(c) Permutit

Question 24.
The formula for permit is …………
(a) Ca Al₂ Si₄ O₁₂
(b) CaAl₃SiO₂. xH₂O
(c) Na₂ Al₂ Si₄ O₁₂
(d) Na₂ SiO₃
Answer:
(c) Na₂ Al₂ Si₄ O₁₂

Question 25.
Which one of the following is used to regenerate permutit in the softening of hard water?
(a) Common salt
(b) Baking soda
(c) Washing soda
(d) Quick lime
Answer:
(a) Common salt

Question 26.
Which of the following is used to demineralise water?
(a) Permutit
(b) Common salt
(c) Ion exchange resin
(d) Charcoal

Question 27.
Which of the following is used during world war as gas masks?
(a) Permutit
(b) Silica gel
(c) Fuller’s earth
(d) Charcoal
Answer:
(d) Charcoal

Question 28.
Which of the following is used in petroleum refining and refining of vegetable oils?
(a) Charcoal
(b) Silica gel
(c) Pcrmutit
(d) Nickel
Answer:
(b) Silica gel

Question 29.
The catalyst used in the hydrogenation of oils to obtain vanaspati is …………
(a) Iron
(b) Molybdenum
(c) Nickel
(d) Copper
Answer:
(c) Nickel

Question 30.
The catalyst and promoter used in Haber’s process are respectively ………..
(a) Mo, Fe
(b) Fe, Mo
(c) Pt, H₂S
(d) Pt, V₂O₅
Answer:
(b) Fe, Mo

Question 31.
Which method is used for identification, detection, and estimation of many substances even if they are in micro quantities?
(a) Lassaigne’s test
(b) Canus method
(c) Kjeldhals method
(d) Chromatography
Answer:
(d) Chromatography

Question 32.
Which one of the following is used in the identification of Al³⁺ ion in Al(OH)₃?
(a) Red litmus
(b) Blue litmus
(c) Phenol red
(d) Sodium hydroxide
Answer:
(b) Blue litmus

Question 33.
Which ores are concentrated by the froth floatation process?
(a) Oxide ore
(b) Carbonate ore
(c) Sulphate ores
(d) Suiphide ores
Answer:
(d) Suiphide ores

Question 34.
In froth floatation process, the lighter ore particles are wetted by …………..
(a) Olive oil
(b) Pine oil
(c) Soap oil
(d) Neem oil
Answer:
(b) Pine oil

Question 35.
Which one of the following is an example of homogeneous catalysis?
(a) Decomposition of acetaldehyde by 12 catalysts
(b) Hydrolysis of cane sugar with a mineral acid
(c) Ester hydrolysis with alkali
(d) All the above
Answer:
(d) All the above

Question 36.
Which one of the following is an example for homogeneous catalysis?
(a) Manufacture of sulphuric acid by contact process
(b) Manufacture of ammonia by Haber’s process
(c) Oxidation of ammonia carried out in the presence of platinum gauze
(d) Hydrolysis of cane sugar with mineral acid
Answer:
(d) Hydrolysis of cane sugar with mineral acid

Question 37.
Which one of the following is an example for heterogeneous catalysis?
(a) Decomposition of acetaldehyde by I₂ catalyst
(b) Decomposition of H₂O₂ in the presence of Pt catalyst
(c) Acid hydrolysis of ester
(d) Hydrolysis of cane sugar with mineral acid
Answer:
(b) Decomposition of H₂O₂ in the presence of Pt catalyst

Question 38.
Which one of the following is not an example for homogeneous catalysis?
(a) Contact process of manufacture of H₂SO₄
(b) Haber’s process of manufacture of NH₃
(c) Acid hydrolysis of ester
(d) Freidel crafts reaction
Answer:
(c) Acid hydrolysis of ester

Question 39.
Consider the following statements:
(i) A catalyst needed in very small quantity
(ii) A catalyst can initiate a reaction
(iii) Catalyst are highly specific in nature

Which of the above statement is/are not correct?
(a) (i) & (iii)
(b) (ii) & (iii)
(c) (iii) only
(d) (ii) only
Answer:
(d) (ii) only

Question 40.
Consider the following statements.
(i) A solid catalyst will be more effective if it is taken in a finely divided form
(ii) A catalyst cannot initiate a reaction
(iii) For a chemical reaction4 catalyst is needed in very large quantity

Which of the above statement is / are not correct?
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) only
(d) (i) & (iii)
Answer:
(a) (i) & (ii)

Question 41.
The catalyst poison in the contact process of manufacture of SO₃ is …………
(a) As₂O₃
(b) H₂S
(c) CO
(d) As₂S₃
Answer:
(a) As₂O₃

Question 42.
In Haber’s process of manufacture of ammonia, the Fe catalyst is poisoned by the pressure of …………….
(a) Mo
(b) Co
(c) H₂S
(d) As₂O₃
Answer:
(c) H₂S

Question 43.
In the reaction 2H₂ + O₂ → 2H₂O acts as a catalytic poison for Pt catalyst.
(a) Co
(b) Mo
(c) As₂O₃
(d) H₂S
Answer:
(a) Co

Question 44.
The negative catalyst in the decomposition of H₂O₂ is …………..
(a) Ethanol
(b) Acetic acid
(c) Ethanoic acid
(d) Methanol
Answer:
(a) Ethanol

Question 45.
Which one of the following is an example tar an autocatalysis?
Answer:

Question 46.
In the decomposition of hydrogen peroxide which acts as a negative catalyst?
(a) Dilute acid
(b) Glycerol
(c) a (or) b
(d) Ethanol
Answer:
(c) a (or) b

Question 47.
The energy required for the reactants to reach the activated complex is called …………
(a) threshold energy
(b) activation energy
(c) internal energy
(d) Gibbs free energy
Answer:
(b) activation energy

Question 48.
Which of the following is explained by intermediate compound formation theory?
(a) Mechanism of Friedel crafts reaction
(b) Thermal decomposition of KClO₃ in the presence of MnO₂
(c) Oxidation of HCl by air in the presence of CuCl₂
(d) Manufacture of NH₃ by Haber’s process
Answer:
(d) Manufacture of NH₃ by Haber’s process

Question 49.
Consider the following statements.
(i) Intermediate compound theory describes the specificity of a catalyst.
(ii) Intermediate compound theory explains the action of catalytic poison and activators.
(iii) Intermediate compound theory is unable to explain the mechanism of heterogeneously catalysed reactions.

Which of the above statement is/are not correct?
(a) (ii) only
(b) (i) & (iii)
(c) (iii) only
(d) (i) & (ii)
Answer:
(a) (ii) only

Question 50.
Who explained the action of catalyst in adsorption theory?
(a) Berzellius
(b) Langmuir
(c) Thomas Graham
(d) Dalton
Answer:
(b) Langmuir

Question 51.
Consider the following statements.
(i) The action of catalytic poison occurs when the poison blocks the active centres of the catalyst.
(ii) A promoter decreases the number of active centres on the surfaces.
(iii) Increase in the activity of a catalyst by increasing the surface area.

Which of the above statement is/are correct?
(a) (ii) only
(b) (iii) only
(c) (i) & (iii)
(d) (ii) & (iii)
Answer:
(c) (i) & (iii)

Question 52.
Which of the following catalyse the chemical reaction in a living organisms?
(a) enzymes
(b) protein
(c) lipids
(d) serum
Answer:
(c) lipids

Question 53.
Which of the following enzyme catalyse the hydrolysis of starch into maltose?
(a) maltase
(b) irivertase
(c) diastase
(d) zymase
Answer:
(c) diastase

Question 54.
Which enzyme catalyses the conversion of glucose into ethanol?
(a) maltase
(b) invertase
(c) diastase
(d) zymase
Answer:
(c) diastase

Question 55.
Which of the following act as catalyst in the oxidation of alcohol into acetic acid?
(a) pepsin
(b) diastase
(c) micro derma
(d) urease
Answer:
(c) micro derma

Question 56.
Which catalyst is used in the hydrolysis of urea?
(a) micro derma
(b) zymase
(c) pepsin
(d) urease
Answer:
(d) urease

Question 57.
Which of the following enzyme is present in soya beans?
(a) urease
(b) zymase
(c) pepsin
(d) lactase
Answer:
(a) urease

Question 58.
Consider the following statements.
(i) Enzymes are complex protein molecules with three-dimensional structures.
(ii) Enzymes catalyse the chemical reaction in living organism.
(iii) Enzymes arc not specific in catalytic action.

Which of the above statement is J are correct?
(a) (iii) only
(b) (ii) & (iii)
(c) (i) & (ii)
(d) (i) & (iii)
Answer:
(c) (i) & (ii)

Question 59.
Consider the following statements.
(i) Enzyme catalysed reaction has maximum rate at optimum temperature
(ii) Enzyme catalysis is highly specific in nature
(iii) Catalytic activity of enzyme is decreased by coenzyrnes or activators.

Which of the above statement is / are not correct?
(a) (iii) only
(b) (i) only
(c) (ii) only
(d) (i) & (ii)

Question 60.
The temperature at which enzyme activity is high (or) maximum is called ………….
(a) critical temperature
(b) optimum temperature
(c) low temperature
(d) high temperature
Answer:
(b) optimum temperature

Question 61.
Enzymes can be active in human body at a temperature of ………….
(a) 98°F
(b) 105°F
(c) 37°F
(d) 50°F
Answer:
(a) 98°F

Question 62.
Consider the following statements.
(i) Zeolites are alumino silicates made of silicon and aluminium tetrahedra.
(ii) Zeolites carrying Na ions are used as basic catalyst.
(iii) As silicon is tetravalent and aluminium is trivalent, the zeolite matrix carries extra positive charge.

Which of the above statement is / are correct?
(a) (i) & (ii)
(b) (i), (ii) & (iii)
(c) (iii) only
(d) (ii) only
Answer:
(a) (i) & (ii)

Question 63.
Which one of the following is used in the petrochemical industry for cracking heavy hydrocarbon fractions into gasoline, diesel, etc.?
(a) permutit
(b) zeolite
(c) pepsin
(d) protein
Answer:
(b) zeolite

Question 64.
Which one of the following is used as a catalyst in the conversion of Lindane to cyclohexane?
(a) Fe°/Pd°
(b) Ni
(c) Zn + HCl
(d) LiAIH₄
Answer:
(a) Fe°/Pd°

Question 65.
Which one of the following is used as catalyst in homogeneous and heterogeneous catalysis?
(a) enzymes
(b) zeolite
(c) nanocatalyst
(d) coenzyme
Answer:
(c) nanocatalyst

Question 66.
Who studied and analysed about colloids?
(a) Berzelius
(b) Thomas Graham
(c) Langmuir
(d) Robert Brown
Answer:
(b) Thomas Graham

Question 67.
Which one of the following is lyophillic colloid?
(a) Protein sol
(b) Gold sol
(c) Silver sol
(d) Platinum sol
Answer:
(a) Protein sol

Question 68.
Which one of the following is lyophobic colloid?
(a) Protein sol
(b) Starch sol
(c) Gel
(d) Gold sol
Answer:
(d) Gold sol

Question 69.
An example of liquid aerosol is ………..
(a) Soda water
(b) Milk
(c) Fog
(d) Inks
Answer:
(c) Fog

Question 70.
Which of the following is an example of Emulsion?
(a) mayonnaise
(b) shaving cream
(c) fumes
(d) paint
Answer:
(a) mayonnaise

Question 71.
The dispersed phase and dispersion medium in smoke, fumes and dust are …………..
(a) gas, solid
(b) solid, gas
(c) gas, liquid
(d) solid, liquid
Answer:
(b) solid, gas

Question 72.
Inks, paints arc considered as …………
(a) liquid in solid
(b) solid in liquid
(c) gas in gas
(d) solid in solid
Answer:
(b) solid in liquid

Question 73.
Which of the following is an example for gel?
(a) Pumice stone
(b) Pearls
(c) Coloured glass
(d) Butter
Answer:
(c) Coloured glass

Question 74.
Which one of the following is an example for solid sol?
(a) Butter
(b) Cheese
(c) Pearls
(d) Pumice stone
Answer:
(c) Pearls

Question 75.
Soda water is an example for ………..
(a) gel
(b) emulsion
(c) foam
(d) sol
Answer:
(c) foam

Question 76.
Colloidal ink and graphite are prepared by …………
(a) colloid mill
(b) Bredig’s arc
(c) ultrasonic homogenizer
(d) peptisation
Answer:
(a) colloid mill

Question 77.
Which method is used to prepare metal sols?
(a) ultrasonic dispersion
(b) mechanical dispersion
(c) Bredigs arc method
(d) peptisation
Answer:
(c) Bredigs arc method

Question 78.
Who prepared non-aqueous inflammable liquids like Benzene and ether by Bredig’s arc method?
(a) George Bredig
(b) Sved berg
(c) Thomas Graham
(d) Robert Brown
Answer:
(b) Sved berg

Question 79.
Which method is used to prepare mercury colloid?
(a) peptisation
(b) mechanical dispersion
(c) ultrasonic dispersion
(d) Bredig’s arc method
Answer:
(c) ultrasonic dispersion

Question 80.
Mercury sol is obtained by subjecting it to sound waves of frequency more than ………..
(a) 20 Hz
(b) 20 kHz
(c) 200 kHz
(d) 2000 kHz
Answer:
(b) 20 kHz

Question 81.
The conversion of a precipitate into colloid is called …………..
(a) coagulation
(b) hydrolysis
(c) condensation
(d) peptisation
Answer:
(d) peptisation

Question 82.
Gold sol is prepared by reduction of auric chloride using …………..
(a) water
(b) HCHO
(c) CH₃CHO
(d) CH₃COOH
Answer:
(b) HCHO

Question 83.
Which method is suitable to prepare I₂ sol and Se sol?
(a) Reduction
(b) Hydrolysis
(c) oxidation
(d) peptisation
Answer:
(c) oxidation

Question 84.
Which condensation method is used to prepare sulphur sol?
(a) Hydrolysis
(b) Decomposition
(c) Reduction
(d) Peptisation
Answer:
(b) Decomposition

Question 85.
Arsenic sulphide colloid is prepared by ………..
(a) hydrolysis
(b) reduction
(c) double decomposition
(d) decomposition
Answer:
(c) double decomposition

Question 86.
By which method phosphorous colloid can be prepared’?
(a) Decomposition
(b) Exchange of solvent
(c) Hydrolysis
(d) Reduction
Answer:
(b) Exchange of solvent

Question 87.
Which one of the following is not used to purify colloids?
(a) Dialysis
(b) Peptisation
(c) Electrodialysis
(d) Uhrafilteration
Answer:
(b) Peptisation

Question 88.
The process of conversion of colloidal solution into precipitate is known as …………..
(a) peptisation
(b) dispersion
(c) coagulation
(d) decomposition
Answer:
(c) coagulation

Question 89.
Which one of the following is named collodion?
(a) 4% solution of nitro cellulose in a mixture of alcohol and water
(b) 40% solution of cellulose acetate in acetic acid.
(c) agar-agar along with gel
(d) semipermeable membrane
Answer:
(a) 4% solution of nitro cellulose in a mixture of alcohol and water

Question 90.
Which of the following is the size of the colloidal particle?
(a) 100 μm diameter – 1000 μm diameter
(b) 1 mμ to 1 μm diameter
(c) 1 mμ to 100 μm diameter
(d) 1 μm to 1 μm diameter
Answer:
(b) 1 mμ to 1 μm diameter

Question 91.
Consider the following statements.
(i) Colloidal solutions are quite stable and are not affected by gravity
(ii) Colloids diffuse more readily through membranes
(iii) Colloidal solutions show colligative properties

Which of the above statement is / are correct?
(a) (i) & (iii)
(b) (ii) & (iii)
(c) (ii) only
(d) (iii) only
Answer:
(a) (i) & (iii)

Question 92.
The shape of tungstic acid W₃O₅ sol is ………….
(a) spherical
(b) disc
(c) plate-like
(d) rod like
Answer:
(d) rod like

Question 93.
Which one of the following colloids has spherical shape?
(a) AS₂S₃
(b) Fe(OH)₃
(c) W₃O₅
(d) dust
Answer:
(a) AS₂S₃

Question 94.
Tyndall effect is possible in colloid due to ……………
(a) absorption of light
(b) adsorption of light
(c) scattering of light
(d) reflection of light
Answer:
(c) scattering of light

Question 95.
Which one of the following does not show Tyndali effect and Brownian movement?
(a) Milk
(b) common salt solution
(c) smoke
(d) tungstic acid sol
Answer:
(b) common salt solution

Question 96.
The migration of sol particles under the influence of electric field is called ……………
(a) electro osmosis
(b) electro dialysis
(c) electrophoresis
(d) dialysis
Answer:
(c) electrophoresis

Question 97.
Which one of the following is used for detection of pressure of charge on sol particles?
(a) Cataphoresis
(b) Electrodialysis
(c) Dialysis
(d) Ultrafiltration
Answer:
(a) Cataphoresis

Question 98.
Which of the following is positively charged colloid?
(a) haemoglobin
(b) starch
(c) clay
(d) AS₂S₃
Answer:
(a) haemoglobin

Question 99.
Which one of the following is a positively charged colloid?
(a) Ag
(b) AU
(c) Basic dyes
(d) Clay
Answer:
(c) Basic dyes

Question 100.
Which one of the following is a negatively charged colloid?
(a) Pt
(b) Al(OH)₃
(c) Fe (OH)₃
(d) Basic dyes
Answer:
(a) Pt

Question 101.
Which one of the following is a negatively charged colloid?
(a) Ferric hydroxide
(b) Clay
(c) Basic dyes
(d) Haemoglobin
Answer:
(b) Clay

Question 102.
The movement of dispersion medium under the influence of electric potential is called ………….
(a) Electrophoresis
(b) Cataphoresis
(c) Electro osmosis
(d) Electro dialysis
Answer:
(c) Electro osmosis

Question 103.
Which one of the following is added to gold sol to protect it?
(a) Gelatine sol
(b) Gum
(c) Starch
(d) Basic dye
Answer:
(a) Gelatine sol

Question 104.
Consider the following statements.
(i) Smaller the gold number, greater the protective power
(ii) Greater the gold number, greater the protective power
(iii) Colloidal sols with opposite charges are mixed, mutual coagulation takes place.

Which of the above statement is / are not correct?
(a) (i) only
(b) (i) & (iii)
(c) (ii) only
(d) (ii) & (iii)
Answer:
(c) (ii) only

Question 105.
Which one of the following can act as emulsifier?
(a) glue
(b) dye
(c) water
(d) starch
Answer:
(a) glue

Question 106.
Which one of the following is not used to identify the types of emulsion?
(a) dye test
(b) viscosity test
(c) conductivity test
(d) Tollen’s test
Answer:
(d) Tollen’s test

Question 107.
By adding which one of the following oil in water emulsion containing potassium soap can be converted into water in oil emulsion?
(a) MCl₃
(b) NaCI
(c) KCI
(d) C₆H₅Cl
Answer:
(a) MCl₃

Question 108.
Which of the following colloid is used as a medicine for stomach troubles?
(a) colloidal Au
(b) colloidal Ca
(c) milk of magnesia
(d) silver sol
Answer:
(c) milk of magnesia

Question 109.
Which one of the following is used in the purification of drinking water?
(a) silver sol protected by gelatine
(b) milk of magnesia
(c) Alum containing Al³⁺
(d) Argyrol
Answer:
(c) Alum containing Al³⁺

Question 110.
Which of the following is used as tonics?
(a) milk of magnesia
(b) Argyrol
(c) colloidal Au & colloidal Ca
(d) Alum
Answer:
(c) colloidal Au & colloidal Ca

Question 111.
Which one of the following is used in tanning of leather?
(a) chromium salt
(b) colloidal Au
(c) Argyrol
(d) Fe (OH)₃
Answer:
(a) chromium salt

Question 112.
Carbon dust in air is solidified by ………..
(a) cottrell’s precipitator
(b) colloidal mill
(c) Bredig’s arc
(d) peptisation
Answer:
(a) cottrell’s precipitator

Question 113.
Which of the following voltage is used in cottrell’s precipitator?
(a) 5000 V
(b) 50,000 V
(c) 1,000V
(d) 10,000V
Answer:
(b) 50,000 V

Question 114.
The blue colour of the sky is due to …………
(a) coagulation
(b) peptisation
(c) Tyndall effect
(d) Brownian movement
Answer:
(c) Tyndall effect

Question 115.
Which one of the following is used to distinguish Natural honey and artificial honey?
(a) Ammoniacal AgNO₃
(b) Fehling’s solution
(c) Arsenic suiphide sol
(d) gelatin
Answer:
(a) Ammoniacal AgNO₃

Question 116.
Which one of the following is the catalyst poison in Haber’s process?
(a) AS₂S₃
(b) AS₂O₃
(c) Co
(d) H₂S
Answer:
(d) H₂S

Question 117.
Which one of the following is an example for water in oil emulsion?
(a) Milk
(b) Vanishing cream
(c) Butter
(d) Soap
Answer:
(c) Butter

Question 118.
Which of the following is contributed towards the extra stability of lyophillic colloid?
(a) Hydration
(b) Charge
(c) Colour
(d) Tyndall effect
Answer:
(a) Hydration

Question 119.
A catalyst is a substance which
(a) increases the equilibrium concentration of the product
(b) changes the equilibrium constant of the reaction
(c) shortens the time to reach equilibrium
(d) supplies energy to the reaction
Answer:
(c) shortens the time to reach equilibrium

Question 120.
The ability of an ion to bring about coagulation of a given colloid depends upon …………
(a) its size
(b) magnitude of its charge
(c) the sign of its charge
(d) both the magnitude and sign of the charge
Answer:
(d) both the magnitude and sign of the charge

Question 121.
Which one of the following is an incorrect statement for physisorption?
(a) It is a reversible process
(b) It requires less heat of adsorption
(c) It requires activation energy
(d) It take place at low temperature
Answer:
(c) It requires activation energy

Question 122.
Which is not a colloid?
(a) Chlorophyll
(b) Egg
(c) Ruby glass
(d) Milk
Answer:
(a) Chlorophyll

Question 123.
Which of the following electrolytes is most effective in the coagulation of gold sol?
(a) NaNO₃
(b) K₄[Fe(CN)₆]
(c) Na₃PO₄
(d) MgCl₂
Answer:
(b) K₄[Fe(CN)₆]

Question 124.
Gold number gives ………………..
(a) the amount of gold present in the colloid
(b) the amount of gold required to break the colloid
(c) the amount of gold required to protect the colloid
(d) the measure of protective power of a lyophillic colloid
Answer:
(d) the measure of protective power of a lyophillic colloid

Question 125.
Identify the gas which is readily adsorbed by activated charcoal?
(a) N₂
(b) SO₂
(c) H₂
(d) O₂
Answer:
(b) SO₂

Question 126.
Starch dispersed in hot water is an example of …………..
(a) emulsion
(b) hydrophobic sol
(c) lyophilic sol
(d) associated colloid
Answer:
(c) lyophilic sol

Question 127.
Which one is an example of gel?
(a) soap
(b) cheese
(c) milk
(d) fog

Question 128.
The random, zig-zag motion of colloidal particles in the dispersion medium is referred to as …………..
(a) Electrophoresis
(b) Brownian movement
(c) Tyndall effect
(d) Electro osmosis
Answer:
(b) Brownian movement

Question 129.
Which of the following electrolytes is least effective in causing flocculation of ferric hydroxide sol?
(a) K₄ [Fe(CN)₆]
(b) K₂CrO₄
(c) KBr
(d) K₂SO₄
Answer:
(c) KBr

Question 130.
Gelatin is mostly used in making icecream in order to …………..
(a) prevent making of colloid
(b) to stabilize the colloid and to prevent the crystallization
(c) to stabilise the mixture
(d) to enrich the aroma
Answer:
(b) to stabilize the colloid and to prevent the crystallization

Question 131.
Which one of the following is not a colloidal solution?
(a) smoke
(b) ink
(c) air
(d) coffee
Answer:
(c) air

Question 132.
Milk can be preserved by adding a few drops of …………
(a) HCOOH
(b) HCHO
(c) CHCOOH
(d) CH₃CHO
Answer:
(b) HCHO

Question 133.
Bleeding is stopped by the application of ferric chloride. This is because …………
(a) ferric chloride seal the blood cells
(b) blood starts flowing in ohter direction
(c) blood is coagulated and blood vessel is sealed
(d) blood is peptised
Answer:
(c) blood is coagulated and blood vessel is sealed

Question 134.
Delta at the rivers are formed due to …………
(a) peptisation
(b) coagulation
(c) hydrolysis
(d) precipitation
Answer:
(b) coagulation

Question 135.
Alum purifies muddy water by …………..
(a) dialysis
(b) adsorption
(c) coagulation
(d) forming a true solution
Answer:
(c) coagulation

Question 136.
Reactions of zeolite catalysts depend on ………….
(a) pores
(b) apertures
(c) size of cavily
(d) all of these
Answer:
(d) all of these

Question 137.
chemisorption ……………
(a) increases with increase in temperature
(b) decreases with increase in temperature
(c) remains unaffected by the, change of temperature
(d) first increases and then decreases.
Answer:
(d) first increases and then decreases.

Question 138.
Adsorption is always …………
(a) endothermic
(b) exothermic
(c) iso thermic
(d) either a (or) b
Answer:
(a) endothermic

Question 139.
Which one of the following can be explained by the adsorption theory?
(a) Homogeneous catalysis
(b) Acid-base catalysis
(c) Heterogeneous catalysis
(d) Enzyme catalysis
Answer:
(c) Heterogeneous catalysis

Question 140.
Physical adsorption is inversly proportional to ……………..
(a) volume
(b) concentration
(c) temperature
(d) all of these
Answer:
(c) temperature

Question 141.
Noble gases are adsorbed by ……………
(a) anhydrous CaCl₂
(b) Fe(OH)₃
(c) Conc. H₂SO₄
(d) activated charcoal
Answer:
(d) activated charcoal

Question 142.
Animal charcoal is used in decolourising agent in the manufacture of sugar because it is a good …………..
(a) adsorbate
(b) adsorbent
(c) oxidising agent
(d) dehydrating agent
Answer:
(a) adsorbate

Question 143.
Gold number is associated only with …………
(a) lyophobic colloids
(b) lyophilic colloids
(c) both lyophobic and lyophilic colloids
(d) Au in water
Answer:
(b) lyophilic colloids

Question 144.
Which of the following forms a colloidal solution with water?
(a) NaCl
(b) Glucose
(c) Starch
(d) Barium sulphate
Answer:
(c) Starch

Question 145.
Which one of the following is an example for homogeneous catalysis?
(a) Hydrogenation of oil
(b) manufacture of NH₃ by Haber’s process
(c) manufacture of sulphuric acid by contact process
(d) hydrolysis of sucrose in the presence of dilute hydrochloric acid
Answer:
(d) hydrolysis of sucrose in the presence of dilute hydrochloric acid

Question 146.
Which of the following does not involve coagulation?
(a) peptisation
(b) formation of delta regions
(c) treatment of drinking water by potash alum
(d) clotting of blood by the use of ferric chloride
Answer:
(a) peptisation

Question 147.
Among the electrolytes Na₂SO₄, CaCI₂, Al₂(SO₄)₃ and NH₄Cl, the most effective coagulating agent for Sb₂S₃ Sol is ……………
(a) Na,SO₄
(b) CaCl₂
(c) Al₂(SO₄)₃
(d) NH₄Cl
Answer:
(c) Al₂(SO₄)₃

Question 148.
Which of the following statement is incorrect regarding physisorption?
(a) It occurs because of Van der Waals forces
(b) more easily liquefiable gases are adsorbed easily
(c) under high pressure, it resuLts into multimolecular layer on adsorbent surface
(d) enthalpy of adsorption is low and positive
Answer:
(d) enthalpy of adsorption is low and positive

Question 149.
Rate of physical adsorption increase with ………..
(a) increase in temperature
(b) decrease in pressure
(c) decrease in temperature
(d) decrease in surface are
Answer:
(c) decrease in temperature

Question 150.
Gold numbers of protective eolloids, A, B, C and D are respectively 0.50, 0.01, 0.10 and 0.005. The correct order of the stability of colloids is ……..
(a) B < D < A < C
(b) D < A < C < B
(c) C < B < D < A
(d) A < C < B < D
Answer:
(d) A < C < B < D

II. Fill in the blanks

The surface of separation of the two phases where the concentration of adsorbed molecule is high is known as …………..
In adsorption, if the concentration of a substance in the interface is high, it is called ……………
The process of removing a adsorbed substance from the surface is called ……………
Adsorption is always accompanied by decrease in ……………
A term …………… is used for sorption of gases on metal surfaces
M.C. Bain introduced a term …………… to represent the simultaneous adsorption and absorption.
In chemical adsorption, gas molecules are held to the surface by formation of chemical bond and nearly …………… is given out as heat of adsorption
In physical adsorption …………… exist between adsorbent and adsorbate
Heat of adsorption is low hence physical adsorption occurs at ……………
…………… involves the formation of activated complex with appreciable activation energy.
Adsorption occurs at fixed sites called ……………
Gases like NH₃, SO₃ and CO₂ are …………… as have greater Van der Waals force of attraction.
gases like H₂, N₂, O₂ have low critical temperature and ………….. slowly
A plot between the amount of adsorbate adsorbed and pressure or concentration of adsorbate at constant temperature is called …………..
Freundlich adsorption isothermal equation is applicable fo adsorption of …………..
During World War I ………….. gas mask was employed
………….. is used to create high vaccum in vessels.
In blast furnace ………….. is used for drying air
For dehydration and also purification of gases like CO₂, N₂, CI₂, O₂ and He ………….. and are employed.
…………..is employed in the softening of hard water to adsorb Ca²⁺ and Mg²⁺ ions
In the process of softening of hard water, exhausted permutit is regenerated by adding a solution of …………..
………….. are used to demineralise water.
………….. and ………….. are used in petroleum refining and refining of vegetable oil.
………….. is used to decolourising agent in manufacture of sugar from molasses.
In forth floation process, the suiphide are particles are wetted by …………..
………….. is defined as a substance which alters the rate of a chemical reaction without itself undergoing chemical change.
The decomposition of acetaldehyde by I₂ catalyst is an example of ………….. catalysis.
Manufacture of sulphuric acid by contact process is an example of ………….. catalysis.
Friedel crafts reaction is an example of ………….. catalysis.
The substances increases the activity of a catalyst are called …………..
………….. or ………….. used as promoter for iron in Haber’s process
………….. destroys the activity of platinum in contact process
In the reaction CH₃COOC₂H₅ + H₂O → CH₃COOH + C₂H₅OH ………….. is act as auto calyst.
The decomposition of H₂O₂ rate is decreased by …………..
As …………..is lowered in the presence of catalyst, more molecules take part in the reaction and hence the rate of the reaction increases.
The mechanism of friedel crafts reaction is explained by ………….. theory.
The catalyst used for the oxidation of HCl by air is …………..
Thermal decomposition of KClO₃ in the presence of ………….. follows ………….. theory.
Intermediate compound formation theory is unable to explain the mechanism of …………..
Hydrogenation of ethylene in the presence of nickel catalyst follows ………….. theory.
………….. are complex protein molecules and catalyse the chemical reaction in living organism.
The enzyme ………….. hydrolyses starch into maltose.
The enzyme ………….. oxidises alcohol into acetic acid.
Enzyme catalysed reaction has ………….. rate at optimum temperature.
………….. in hibits the action of bacteria and used for curing pneumonia.
………….. are microporous, hydrated alumino silicates.
Zeolites carrying ………….. are used as basic catalysts
Like heterogeneous catalyst ………….. can be recovered and recycled.
Sols of gold, silver, platinum and copper are examples of …………..
So is of protein and starch are examples of …………..
A liquid in liquid colloid is called …………..
Pearls, opals and Ruby red glass are belong the colloid named …………..
Rubber forns colloidal solution with …………..
In colloid mill, the two metal plates rotating in opposite directions of nearly ………….. revolution per minute.
Colloidal solutions of ink and graphite are prepared by ………….. method.
A brown colloidal solution of platinum was prepared by ………….. in 1898.
………….. is added as an stabilising agent for making platinum colloid.
Metal hydroxide is added as an ………….. for making noble metal sols.
Claus obtained ………….. by subjecting ………….. to high frequency ultrasonic vibrations,
In the preparation of AgCI colloid from AgCl precipitate, the peptising or dispersing agent used is …………..
Gold sol is prepared by reduction of auric chloride using …………..
Arsenic sulphide colloid can be prepared by ………….. method.
12 sol is obtained from HIO₃ by ………….. method.
The process of conversion of colloidal solution into precipitate is called …………..
In the dialysis of kidney. recycling of patient’s blood is done through semipermeable tube in an ………….. solution
Collodion is 4% solution of ………….. in a mixture of …………..
The size of colloidal particles ranges from …………..
The shape of blue gold sol (or) Fe(OH)₃ sol is …………..
Pollen grains suspended in water showed …………..
The flocculation and setting down of sol particles is called …………..
When the valency of ion is high ………….. power is increased in colloids.
The smaller the ………….. value, greater will be precipitation of colloids.
………….. is added to gold sol to protect it.
………….. introduced the term gold number as a measure of protecting power of a colloid.
An oil in watrer emulsion containing potassium soap as emulsifying agent can be converted into water in oild emulsion by adding ………….. or …………..
Synthetic polymers like polystyrene, silicones and PVC, are …………..
………….. colloid is used as eye lotion.
………….. protected by gelatin is known as Argyrol.
………….. salts arc used in tanning of leather.
Natural honey is distinguished artificial honey by adding …………..

Answer:

interface
positive adsorption
desorption
free energy
occlusion
sorption
400kJ/rnole
Van der Waals forces of attraction
low temperature
Chemisorption
active centres
easily liquefiable
Permanent, adsorbed
Adsorption isotherm
gases on solid surface
charcoal
Activated charcoal
silica gel
alumina, silica
Permutit
common salt
Con exchange resins
Fuller’s earth, silica gel
Animal charcoal
pine oil
catalyst
homogeneous
heterogeneous
heterogeneous
promoters
Mo (or) Al₂O₃
AS₂O₃ catalyst poison
CH₃COOH
ethanol (or) Glycerol, negative catalyst
Activation energy
intermediate compound formation
CuCI₂
MnO₂, intermediate compound formation theory
heterogeneous catalysis
adsorption
enzymes
diastase
micoderma aceti
maximum
penicillin
zeolites
Na ions
nano catalyst
lyophobic sols (or) irreversible sols
lyophilic sols (or) reversible sols
emulsion
solid sol
benzene
7000
mechanical dispersion
George Bredig
alkali hydroxide
stabilising agent
mercury sol, mercury
HCl
formaldehyde
double decomposition
oxidation
coagulation
isotonic saline
nitro cellulose, alcohol and water
1 mi to llim diameter
disc or plate like
Brownian movement
coagulation
precipitation
flocculation
geLatine sol
Zsigmondy
CaCl₂, AlCl₃
colloids
Argyrol
Silver sol
chromium
Tollens reagent (or) Ammoniacal AgNO₃

III. Match the column I & II using the code given below the coulum.

Question 1.

Answer:
(a) 4 3 1 2

Question 2.

Answer:
(c) 3 4 1 2

Question 3.

Answer:
(a) 4 3 1 2

Question 4.

Answer:
(a) 2 3 4 1

Question 5.

Answer:
(b) 3 4 2 1

Question 6.

Answer:
(a) 3 1 4 2

Question 7.

Answer:
(a) 4 1 2 3

Question 8.

Answer:
(a) 4 3 2 1

Question 9.

Answer:
(a) 2 4 1 3

Question 10.

Answer:
(a) 4 3 1 2

Question 11.

Answer:
(c) 3 1 4 2

Question 12.

Answer:
(a) 4 3 1 2

Question 13.

Answer:
(d) 3 1 4 2

Question 14.

Answer:
(b) 4 3 2 1

Question 15.

Answer:
(a) 2 4 1 3

Question 16.

Answer:
(b) 3 4 2 1

Question 17.

Answer:
(a) 4 1 2 3

Question 18.

Answer:
(a) 3 1 4 2

IV. Assertion and Reason

Question 1.
Assertion (A) : Absorption is a bulk phenomenon.
Reason (R) : The absorbed molecules are distributed throughout the absorbent.
(a) Both A and R are correct and R is the correct explanation of A.
(b) A is correct but R is wrong.
(c) A is wrong but R is correct.
(d) Both A and R are wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 2.
Assertion (A) : Adsorption is a spontaneous process.
Reason (R) : Adsorption is always accompanied by decrease in free energy. When molecules are adsorbed, there is always a decrease in randomness of the molecules.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) Both A and R are wrong.
(d) A is correct but R is wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 3.
Assertion (A) : Chemical adsorption is an exothermic process.
Reason (R) : In chemical adsorption, gas molecules are held to the surface by formation of chemical bonds. Since strong bond is formed, nearly 400kJ/mole is given out as heat adsorption.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) Both A and R are wrong.
(d) A is correct but R is wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 4.
Assertion (A) : Physical adsorption occurs at low temperature.
Reason (R) : ¡n physical adsorption, weak Van der Waals force of attraction exist. Other weak forces exist in physical adsorption are dipole-dipole interaction and dispersion forces. As these forces are weak, heat of adsorption is low.
(a) Both A and R are correct but R is not correct explanation of A.
(b) Both A and R are correct and R is the correct explanation of A.
(c) Both A and R are wrong.
(d) A is correct but R is wrong.
Answer:
(b) Both A and R are correct and R is the correct explanation of A.

Question 5.
Assertion (A) : Platinised asbestos is a better adsorbent than platinum block.
Reason (R) : Higher the surface area, higher is the amount adsorbed. In platinum coated asbestos the surface area is more and so it act as a better adsorbent.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are wrong.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 6.
Assertion (A) : Gases like SO₂, NH₃ and CO2 are readily adsorbed.
Reason (R) : SO₂, NH₃ and CO₂ are easily liquefiable as have greater van der WaaI’s forces of attraction and adsorbed readily.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and Rare wrong.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 7.
Assertion (A) : Permanent gases like H₂, N₂ and O₂ cannot be adsorbed readily.
Reason (R) : Permanent gases having low critical temperature and adsorbed slowly.
(a) Both A and R are wrong.
(b) A is correct and R is the correct explanation of A.
(c) A is wrong but R is correct.
(d) A is correct but R is wrong.
Answer:
(b) A is correct and R is the correct explanation of A

Question 8.
Assertion (A) : Chromatography is a very effective method and used for identification, detection and estimation of micro quantities of many substances.
Reason (R) : Chromatography technique is applied for separation and detection of components in a mixture it is mainly based on adsorption of components on the surface of adsorbents.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 9.
Assertion (A) : Ester hydrolysis of acid (or) alkali catalyst is an example of homogeneous catalysis.
Reason (R) : Ester, H₂O acid (or) alkali and the products are in liquid form.
(a) Both A and R are correct but R is the correct explanation of A.
(b) Both A and R are wrong.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct,
Answer:
(a) Both A and R are correct but R is the correct explanation of A.

Question 10.
Assertion (A) : The manufacture of sulphuric acid by contact process is an example of heterogeneous catalysis.
Reason (R) : The catalyst Pt (or) VO₅, reactants and products are in different phases in contact process.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) Both A and R are wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 11.
Assertion (A) : Acid hydrolysis of ethylacetate by water to produce acetic acid and ethanol is an example of auto catalysis.
Reason (R) : In acid hydrolysis of ester, the product acetic acid act as catalyst and this process is called autocatalysis.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are wrong.
(c) A is correct hut R is wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 12.
Assertion (A) : Effective and efficient conversion is the special characteristic of enzyme catalysed reactions.
Reason (R) : An enzyme may transform a million molecules of reactants to products in a minute.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) A is correct but R is wrong.
(d) A is wrong but R is correct.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 13.
Assertion (A) : lyophillic colloids will not get precipitated easily.
Reason (R) : In lyophillic colloids, definite attractive forces exists between dispersion medium and dispersed phase and they are more stable.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) Both A and R are wrong.
(d) A is correct but R is wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 14.
Assertion (A) : Lyophobic colloids like sols of gold will precipitate readily.
Reason (R) : In lyophobic colloids, no attractive force exists between the dispersed phase and dispersion medium and are less stable.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are correct but R is not correct explanation of A.
(c) Both A and R are correct.
(d) A is correct but R is wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

Question 15.
AssertIon (A) : Iron colloid cannot be prepared by Bredig’s arc method.
Reason (R) : iron cannot react with alkali hydroxide stabilising agent added in water.
(a) Both A and R are correct and R is the correct explanation of A.
(b) A is correct but R is wrong.
(c) A is wrong but R is correct.
(d) Both A and R are wrong.
Answer:
(a) Both A and R are correct and R is the correct explanation of A.

V. Find the odd one out.

Question 1.
He, Ne, O₂, N₂, Pt
Answer:
Pt. It is adsorbent and all others are adsorbates.

Question 2.
SO₂, NH₃, NaCI, Silica gel
Answer:
Silica gel. It is an adsorbent whereas others are adsorbates.

Question 3.
Silica gel, Pt, Ag, Pd, NH₃
Answer:
NH₃ It is an adsorbate whereas others are adsorbents.

Question 4.
Coconut charcoal, silica gel, mica, SO₂, Animal charcoal
Answer:
SO₂ It is an adsorbate whereas others are adsorbents.

Question 5.
Mica, Nickel, Charcoal, Tungsten, Ethyl alcohol vapours
Answer:
Ethyl alcohol vapours. It is an adsorbate whereas others are adsorbents.

Question 6.
Pt, Glycerol, MnO₂, Ni, I₂
Answer:
Glycerol. It is a negative catalyst whereas others are positive catalyst.

Question 7.
Fe, Anhydrous AlCl₃, V₂O₅, Pt, Ethyl alcohol
Answer:
Ethyl alcohol is a negative catalyst whereas others are positive catalyst.

Question 8.
Decomposion of acetaldehyde by I₂ Decomposition of H₂O₂ by Pt, Ester hydrolysis with acid, Hydrolysis of cane sugar.
Answer:
Decomposition of H₂O₂ by Pt. It is heterogeneous catalysis whereas others are homogeneous catalysis.

Question 9.
Friedel crafts reactopm, Haner’s process, Hydrolysis of cane sugar, contact process.
Answer:
Hydrolysis of cane sugar. It is homogeneous catalysis whereas others are heterogeneous catalysis.

Question 10.
Pepsin, Zymase, Maltase, Diastase, Maltose, Urease.
Answer:
Maltose. It is a carbohydrate whereas others are enzyme catalysts.

Question 11.
Pt, Ni, Fe°/Pd°, Fe/Mo, Sn/HCI
Answer:
Fe°/Pd°. It is a nano catalyst where as others ordinary catalyst.

Question 12.
Milk, coffee, smoke, common salt solution, dust.
Answer:
Common salt solution. It is a true solution whereas others are colloids.

Question 13.
Soda water, Butter, Starch solution, Cheese, Cream.
Answer:
Starch solution. It is a suspension whereas others are colloids.

Question 14.
Ink, Milk, Cream, Mayonnaise.
Answer:
Ink. It is a sol whereas others are Emulsion.

Question 15.
Pearls, Opals, Coloured glass, Alloys, Pumice stone.
Answer:
Pumice stone. It is a solid foam whereas others are solid sol.

Question 16.
Smoke, Froth, Fumes, Dust, Air pollutants.
Answer:
Froth. It is a foam whereas others are solid aerosol.

Question 17.
Pumice stone, Foam, Milk, Rubber band.
Answer:
Milk. It is an emulsion whereas others are solid foam.

Question 18.
Mechanical dispersion, Bredigts arc method, Peptisation, Double decomposition, Ultrasonic dispersion.
Answer:
Double decomposition. It is a condensation method of preparation of colloids whereas others are dispersion methods of preparation of colloids.

Question 19.
Oxidation, Peptisation, Reduction, Decomposition, Hydrolysis.
Answer:
Peptisation. It is a dispersion method of preparation ofcoiloid whereas others are condensation methods of preparation of colloids.

Question 20.
Dialysis, electrophoresis, Ultrafi iteration. Electrodialysis.
Answer:
Electrophoresis is an electrical property of colloids but others are purification methods of colloids.

Samacheer Kalvi 12th Chemistry Surface Chemistry 2 Marks Questions and Answers

Question 1.
Define

Adsorbent
Adsorbate with an example.

Answer:

Adsorbent is a material on which adsorption takes place. eg., silica gel and metals like Ni, Cu, Pt.
Adsorbate is a substance which is adsorbed on the adsorbent. e.g., Gaseous molecules like He, Ne, O₂, N₂ and solutions of NaCI (or) KCI.

Question 2.
Define

Interface
Desorption.

Answer:
1. Interface:
The surface of separation of the two phases where the concentration of adsorbed molecule is high is known as interface.

2. Desorption:
The process of removing an adsorbed substance from the substance is called desorption.

Question 3.
What is adsorption? What is meant by positive and negative adsorption?
Answer:
Adsorption is the odhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. In adsorption, if the concentration of a substance in the interface is high, then it is called positive adsorption. 1f it is less, then it is called negative adsorption.

Question 4.
Define chemical adsorption? Give example.
Answer:
Chemical adsorption is a process in which gas molecules are held to the surface by formation of chemical bonds. e.g., Adsorption of O₂ on tungsten, Adsorption of H₂ on nickel.

Question 5.
Chemical adsorption is an exothermic process. Justify this statement.
Answer:
In chemical adsorption, gas molecules are held to the surface by the formation of strong bond. Due to this 400kJ/mole is given out as heat of adsorption. Since heat is evolved, it is an exothermic process.

Question 6.
Why physical adsorption take place at low temperature?
Answer:
In physical adsorption, the forces between the adsorbent and adsorbate are very weak, heat of adsorption is low and hence physical adsorption occurs at low temperature.

Question 7.
What are the forces exist in physical adsorption?
Answer:
In physical adsorption, physical forces like van der Waals force of attraction exist between adsorbent and adsorbate.
The other forces that can cause physical adsorption are

dipole-dipole interaction
dispersion forces.

Question 8.
What is physical adsorption? Give example.
Answer:
Physcial adsorption is a process in which adsorbate are attached to adsorbent by means of weak van der Waals forces of attraction. e.g.,

Adsorption of N₂ on mica
Adsorption of gases on charcoal.

Question 9.
Finely divided Nickel is a better adsorbent than Nickel crystal.
Answer:
As the adsorption is a surface phenomenon it depends on the surface area of adsorbent. i.e., higher the surface area, higher is the amount adsorbed. Finely divided Nickel has longer surface area and it is a better adsorbent than Nickel crystal.

Question 10.
NH₃, CO₂ are readily adsorbed where as H₂, N₂ are slowly adsorbed. Give reason.
Answer:
1. The nature of adsorbate can influence the adsorption. Gases like NH₃ CO₂ are easily liquefiable as have greater van der Waals forces of attraction and hence readily adsorbed due to high critical temperature.

2. But permanent gases like H₂, N₂ can not be easily liquefied and having low critical temperature and adsorbed slowly.

Question 11.
What is meant by adsorption isotherm?
Answer:
A plot between the amount of adsorbate adsorbed and pressure or concentration of adsorbate at constant temperature is called adsorption isotherm.

Question 12.
Mention Freundlinch adsorption isothermal equation.
Answer:
Freundlinch adsorption isotherm
$\frac{x}{m}=k p^{1 / n}$
where x is the amount of adsorbate or adsorbed on ‘m’ gm of adsorbent at a pressure of p. k and n arc constants.

Question 13.
What are the limitations of Freundlich adsorption isotherm?
Answer:

The Freundlich adsorption isotherm is purely empirical and valid over a limited pressure range.
The values of constants ‘k’ and ‘n’ also found vary with temperature. No theoritical explanations were given.

Question 14.
How is adsorption applied in the decolourisation of sugar?
Answer:
Sugar prepared from molasses is decolourised to remove coloured impurities. Animcal charcoal is applied to adsorb colouring impurities and sugar is purified.

Question 15.
What is chromatography?
Answer:
1. The chromatographic technique is a process of separation of components in a mixture which is mainly based on adsorption of components on the surface of adsorbents.

2. This method is very effective and used for identification, detection and estimation of many substances even if they are contained in micro quantities.

Question 16.
Explain the application of adsorption ¡n qualitative analysis with an example.
Answer:
1. In the identification of Al³⁺ ion in Al(OH)₃ is obtained as blue lake. Due to adsorption of blue litmus solution added to the aluminium ion solution.

2. A red colouration is seen due to the acidic nature of the solution. Ammonium hydroxide is added to it until the bkie colour develops.

3. During this addition, Al(OH)₃ precipitate is formed with blue colour due to the adsorption of litmus compound.

Question 17.
Define catalyst. Give example.
Answer:
A catalyst is defined as a substance which alter the rate of chemical reaction without itself undergoing chemical change. The phenomenon which involves the action of a catalyst is called catalysis.
e.g.,

Question 18.
What is homogeneous catalysis? Give example.
Answer:
Homogeneous catalysis is a process in which the reaction, products and catalyst are present in the same phase. NO
e.g.
In the above reaction, the catalyst NO, the reactants SO₂, O₂ and product SO₃ are present in the gaseous form

Question 19.
What is heterogeneous catalysis? Give example.
Answer:
Heterogeneous catalysis is a process in which the reactants, products and catalyst are present in different phases.
e.g.

Question 20.
What are promoters? Explain with example.
Answer:
1. In a catalysed reaction, the presence of a certain substance increases the activity of a catalyst. Such substance is called a promoter.

2. For example, in Haber’s process of manufacture of ammonia, the activity of the iron catalyst is increased by the presence of molybdenum. Hence molybdenum is called a promoter.

Question 21.
What is meant by catalyst poison?
Answer:
1. The substances when added to a catalysed reaction decreases or completely destroys the activity of a catalyst are often known as catalytic poisons.

2. In the reaction 2SO₂ + O₂ → 2SO₃ with Pt catalyst, the catalyst poison is AS₂O₃.

Question 22.
Which is the catalyst and catalyst poison In Haber’s process?
Answer:
In the Haber’s process of the manufacture of ammonia, the Fe is catalyst and it is poisoned by the presence of H₂S.
3H₂ + N₂ → 2NH₃ Fe – catalyst, H₂S – Catalyst poison

23. In the reaction 2H₂ + O₂ → 2H₂O, which ¡s the catalyst and catalyst poison?
Answer:

Pt – catalyst
CO act as catalytic poison for Pt catalyst.

Question 24.
Explain the relation between activation energy and the rate of the reaction using catalyst.
Answer:
1. For a chemical reaction to occur, the reactants are to be activated to form a activated complex. The energy required for the reactants to reach the activated complex is called the activation energy. The activation energy can be decreased by increasing the reaction temperature.

2. In the presence of catalyst, the reactants are activated at reduced temperatures. i.e., the activation energy is lowered. The catalyst adsorbs the reactants activates them by weakening the bonds and allow them to react to form products.

3. As activation energy is lowered in the presence of a catalyst, more molecules take part in the reaction and hence the rate of the reaction increases.

Question 25.
What are the merits and limitations of the intermediate compound theory?
Answer:
Merits:

The specificity of a catalyst
The mercase in the rate of the reaction with increase in the concentration of catalyst.

Limitations:

This theory fails to explain the action of catalytic poison and promoters.
This theory is unable to explain the mechanism of heterogeneous catalysed reactions.

Question 26.
What are active centres?
Answer:

The surfiice of a catalyst is not smooth. It bears steps, cracks and corners. Hence the atoms on such locations of the surface are coordinatively unsaturated.
The have residual force of attraction. Such sites are called active centres. So the surface cames high surface free energy.

Question 27.
Enzyme catalysis are more effective and efficient than ordinary catalysis. Prove this statement.
Answer:
1. Effective and efficient conversion ¡s the special chareteristic of enzyme catalysed reactions. An enzyme may transform a million molecules of reactant to product in a minute.
For e.g. 2H₂O₂ → 2H₂O + O₂

2. For this reaction colloidal platinum as a catalyst the activation energy is 11 .7 k.cal/mole. But with the enzyme catalyst the activation energy of this reaction is less than 2k.cal/mole.

Question 28.
Enzyme catalysis is highly specific in nature. Justify this statement.
Answer:
1. Urea can be hydrolysed to urea by the enzyme urease.

The catalyst mease (enzyme) catalyses urea but it does not hydrolyse methyl urea.

Question 29.
Enzyme catalysed reaction has maximum rate at optimum temperature. Prove it.
Answer:
1. At first rate of reaction increases with the increase of temperature, but above a particular temperature, the activity of enzyme is destroyed. The rate may even drop to zero. The temperature at which enzymic activity in high or maximum is called optimum temperature.

2. For e.g., enzymes involved in human body have an optimum temperature 37°C/98°F.

Question 30.
What are the types of colloids based on dispersion medium?
Answer:

1. If the dispersion medium considered as water, then the colloids are referred as hydrosols (or) aquasols.
2. If the dispersion medium is an alcohol, the colloid is termed as alcosol. and if benzene is the dispersion medium, it is called benzosol.

Question 31.
Explain about

Liquid aerosol
solid aerosol with example.

Answer:

Question 32.
Explain oxidation method of preparation of colloids with two examples.
Answer:
Oxidation:
1. When hydrolodic acid is treated with iodic acid 12 sol is obtained.
HIO₃ + 5HI → 3H₂O + 3I₂ (sol)

2. When O₂ is passed through H₂Se, a sol of selenium is obtained.
H₂Se + O₂ → 2H₂O + Se (sol)

Question 33.
Explain the method of preparation of gold sol by reduction method.
Answer:
Gold sol is prepared by the reduction of auric chloride using formaldehyde.
2AuCl₃ + 3HCHO + 3H₂O → 2Au (sol) + 6HCI + 3HCOOH

Question 34.
How would you prepare ferric hydroxide sol by hydrolysis method?
Answer:
Fe(OH)₃ sol can be preparcd by the hydrolysis of FeCl₃
FeCI₃ + 3H₂O → Fe(OH)₃ (soL) + 3 HCI

Question 35.
How would you prepare colloid by the exchange of solvent method?
Answer:
1. Colloidal solution of few substances like phosphorous or sulphur is obtained by the solutions in alcohol and pouring them into water.
2. As they are insoluble in water, they form colloidal solution.
P in alcohol + water → P_sol.

Question 36.
Why colloids are to be purified? If not what will happen?
Answer:

The colloidal solutions due to their different methods ofpreparation may contain impurities.
If they are not removed, they may destabilise and precipitate the colloidal solution. This is called coagulation.
Hence the impurities mainly electrolytes should be removed to increase the stabilisation of colloid.

Question 37.
How is human kidney dialysis take place?
Answer:

Kidney malfunction results in the building up of electrolyte concentration within the blood to toxic levels.
In the dialysis. recycling of patient’s blood is done through considerable length of semipermeable tube in an isotomic saline solution.

Question 38.
Write a note about Helmoholtz double laver.
Answer:
The surface of a colloidal particle adsorbs one type of ion due to preferential adsorption. This Stem layer
layer attracts the oppositely charged ions in the. medium and hence the boundary separating the Slpping plane two electrical double layers are set up. This is called Helmholtz electrical double layer. As the particles nearby are having similar charges. they cannot come close and condense. Hence this helps to explain the stability of the colloid.

Question 39.
What is meant by gold number?
Answer:

Zsigmondy introduced the term “Gold number” as a measure of protective power of a colloid.
Gold number is defined as the number of milligrams of hydrophilic colloid that will just prevent the precipitation of 10 ml of gold sol on the addition of 1 ml of 10% NaCI solution.

Question 40.
Potato starch is less stable than gelatin. Why?
Answer:

The gold number of gelatin is 0.005 – 1 and the gold number of potato starch is 25.
Smaller the gold number, greater the protective power.

Question 41.
Write a note about Cortrell’s precipitator.
Answer:
Carbon dust in air is solidified by Cortrell’s precipitator. In it. a high potential difference of about 50.000V is used. The change on carbon is neutralised and solidified. Thus the air is free from carbon particles.

Question 42.
Explain about

blue colour of the sky
formation of delta.

Answer:

The blue colour of the sky in nature is due to Tyndall effect of air particles.
The electrolytes in sea and river water coagulate the solid particles in river water at their intersection. By this way delta is formed.

Question 43.
Distinguish between the meaning of the terms adsorption and absorption. Give one example each.
Answer:
Adsorption

Substance is concentrated only at the surface and does notpcnctrate from the surface to the bulkofthe adsorbent.
It is a surface phenomenon.
Example: Silical gel absorbs water vapour on its surface.

Absorption

Substnce is uniformly distributed throughout the bulk of the solid.
It is a bulk phenomenon.
Example: Anhydrous CaCl, absorbs water vapours in it.

Question 44.
Explain the following term giving a suitable example, emulsification.
Answer:
The process of making emulsion using a mixture of two immiscible or partially miscible liquids is called emulsification. For example. Cod liver oil is an emulsion made up of water in oil.

Question 45.
What is the reason for the stability of colloidal sols?
Answer:
Reason for the stability of colloidal sols are:

Coagulation of the colloidal sol is prevented because of the presence of equal and similar charges on the colloidal particles.
Colloidal particles are covered by a sheath of liquid in which they are extensively solvated because of which they acquire stability.

Question 46.
Dialysis is a method of purification of sols. But prolonged dialysis of the sol makes it unstable. Why?
Answer:
Traces of electrolytes in the sol, impart charge to the dispersed phase particles making it stable. Prolonged dialysis removes all the electrolytes, thus making the sol unstable.

Question 47.
Why the sun looks red at the time of setting? Explain on the basis of colloidal properties.
Answer:
At the time of setting, the sun is at the horizon. The light emitted by the sun has to travel a longer distance. As a result the blue part of the light is scattered away by the dust particles in the atmosphere. Hence the red part is visible.

Question 48.
What are emulsions? What are their different types? Give one example of each type.
Answer:
An emulsion is a colloidal dispersion in which both the dispersed phase and the dispersion medium are liquids and the two liquids involved are otherwise immiscible.
1. Oil in water type, in which oil is a dispersed phase and water is the dispersion medium, For example: milk is as emulsion of liquid fat dispersed in water.

2. Water in oil type. in which water is the dispersed phase and oil is thedispersion medium. For example: cod liver oil is an emulsion of water in oil in which water is the dispersed phase and oil is the dispersion medium.

Question 49.
How does chemical adsorption of a gas on a solid vary with temperature?
Answer:
Chemical adsorption first increases with increase in temperature and then it decreases, if the pressure remains constant.

Question 50.
What are lyophilic and lyophobic sols? Give one example of each type. Why are hydrophobic sols easily coagulated?
Answer:
Lyophilic Sols:
Colloidal sols directly formed by rnixing substances like gums, gelatin, starch, rubber. etc. with a suitable liquid (The dispersion medium) are lyophilic sols. An important characteristic of these sols is that if the dispersion medium is separated from the dispersed phase

(say by evaporation) the sol can be reconstituted by simply remixing with the dispersion medium. That is why these sols are also called reversible sols. These sols are quite stable and cannot be easily coagulated.

Lyophobic sols:
These colloidal sols can only be prepared by some special methods. These sols are readily precipitated on the addition of small amount of electrolytes, by heating or by shaking and hence are not stable.

Hydrophobic sols are water hating. They are formed by indirect method. These sols are irreversible sols. These sols are readily precipitated by the addition of small amount of electrolytes, by heating or by shaking and hence are not stable.

Samacheer Kalvi 12th Chemistry Surface Chemistry 3 Marks Questions and Answers

Question 1.
What are the characteristics of adsorption?
Answer:
1. Adsorption can occur in all interfacial faces i.e., the adsorption can occur in between gas – solid, liquid – solid, liquid – liquid, solid – solid and gas – liquid.

2. Adsorption is always accompanied by decrease in free energy. When ∆G reaches zero, the equilibrium is attained.

3. Adsorption is a spontaneous process.

4. When molecules are getting adsorbed, there is always decrease in randomness of the molecules.
∆G = ∆H – T∆S where ∆G = change in free energy
∆H change in enthalpy
∆S change in entropy
∆H = ∆G + T∆S

5. Adsorption is exothermic and it is a quick process.

6. If simultaneous adsorption and absorption take place, it is termed as ‘sorption and sorption of gases on metal surface is called occlusion.

Question 2.
Explain graphical representation of chemical adsorption and physical adsorption.
Answer:
1. Adsorption isotherms represents the variation of adsorption at constant temperature.

2. When amount ?f adsorption is plotted versus temperature at constant pressure is called adsorption iso bar

3. In physical adsorption x/m decreases with increase in T. But in chemical adsorption x/m increases with rise in temperature and then decreases. The increase illustrate the requirement of activation of the surface for adsorption is due to the fact that formation of activated complex require certain energy. The decrease at high temperature is due to desorption, as the kinetic energy of the adsorbate increases.

Question 3.
Write any 3 applications of adsorption.
Answer:

Gas masks: During World War I. charcoal gas mask was employed.
To create high vaccum in vessels, activated charcoal is used. For dehydration and purification of gases like CO₂, N₂, O₂ and He, alumina and silica gel are employed.
In blast furnace, silica gel is used for drying air.

Question 4.
Explain the function of permutit in the softening of hard water.
Answer:
1. Permutit is employed for softening 6 hard water. It adsorbs Ca₂ and Mg₂ ions in its surface, there is an ion exchange as shown below it occurs on the surface.

2. Exhausted permutit is generated by adding a solution of commonsalt.

Question 5.
Explain about the application of ion exchange resins In adsorption.
Answer:

Ion exchange resins are working only based on the process of adsorption.
Ion exchange resins are used to demmeralise water. This process is carried out by passing water through two columns of cation and anion exchange resins.

Question 6.
What is catalysis? Explain with two examples.
Answer:
Catalysis is a process in which a chemical reaction takes place in a faster rate with the help of catalyst.
Haber’s process:
N₂ + 3H₂ → 2NH₃ In this process. Fe is the catalyst and Mo is the promoter.
The surface of Fe catalyses the reaction.

Vanaspathi preparation:

Nickel surface catalyses the reaction.

Question 7.
In the following fields, how adsorption ¡s applied?

Medicine
Metallurgy
Mordant & Dyes
indicators

Answer:
1. Medicine:
Drugs cure diseases by adsorption on body tissues.

2. Metallurgy:
Sulphide ores are concentrated by a process called froth floation in which lighter ore particles are adsorbed by pine oil. .

3. Mordants and Dyes:
Most of the dyes are adsorbed on the surface of the fabric. Mordants are the substances used for fixing dyes onto the fabric.

4. In the precipitation titrations, the end point is indicated by an external indicator which changes its colour aller getting absorbed on precipitate. It is used to indicate the end point of filtration.

Question 8.
Differentiate homogeneous and heterogeneous catalysis.
Answer:
Homogeneous catalysis

The reaction in which, the reactants, products and catalyst are present in the same phase, is called homogeneous catalysis.
Homogeneous catalysis mechanism is ex plained by intermediate compound formation theory.

Heterogeneous catalysis

The reaction in which the reactants, products and catalyst are present in different phases is called heterogeneous calalysis.
Heterogeneous catalysis mechanism is explained by adsorption theory.

Question 9.
Give three examples for homogeneous catalysis.
Answer:
1. Decomposition of acetaldehyde by I₂ catalyst.

2. Hydrolysis of cane sugar with mineral acid

3. Acid hydrolysis of an ester

Question 10.
Give three examples for heterogeneous catalysis
Answer:
1. hydrogenation of ethylene in the presence of Nickel

2. Decomposition of H₂O₂ with Pt catalyst

3. Friedel crafts reaction

Question 11.
What is auto ctalysis? Give two examples
Answer:
The process in which one of the product formed act as a catalyst is termed auto catalysis

Acetic acid acts as auto catalyst.
Decomposition of Arsenic hydride

Arsenic act as auto catalyst.

Question 12.
What is negative catalysis? Explain with example.
Answer:

1. In certain reactions, presence of certain substances decreases the rate of the reaction. Such substances are called negative catalyst and the process is called negative catalysis.

2. In oxidation of chloroform, ethanol decreases the rate of the reaction and ethanol act as negative catalyst.

Question 13.
Explain the formation of water with copper catalyst by Intermediate compound formation theory.
Answer:
1. Formation of water due o the reaction of H₂ and O₂ in the presence of Cu can be given as

Question 14.
Explain the mechanism of oxidation of HCl by air in the presence of CuCl₂
Answer:

Question 15.
Explain the thermal decomposition of potssium chlorate by intermediate compound formation theory.
Answer:
1. Thermal decomposition of KClO₃ in the presence of MnO₂ proceeds as follows.

Question 16.
Describe the action of active centres present in the catalyst.
Answer:
1. Active centres increases the rate of the reaction by adsorbing and activating the reactants.

2. Increase in the activity of a catalyst by increasing the surface area. Increase in the surface area of metals and metal oxides by reducing the particle size increases the rate of the reaction.

3. The action of catalytic poison occurs when the poison blocks the active centres of the catalyst.

4. A promoter (or) activator increases the number of active centres on the surface.

Question 17.
Write a note about nano catalyst.
Answer:

Nano materials such as metallic nano particles, metal oxide are used as catalyst in many chemical transformation.
Nano catalysts carry the advantages of both homogeneous and heterogeneous catalysis.
Like homogeneous catalyst the nino catalyst give 100% selective transformations and excellent yield and show extremely high reactivity.
Like the heterogeneous catalyst, nano catalysts can be recovered and recycled.
Nano catalysts are actually soluble heterogeneous catalyst.

Question 18.
Differentiate lyophillic and lyophobic colloids
Answer:
Lyophiltic colloids

In lyophillic colloids (or) sols definite attractive force (or) affinity exists between dispersion medium and dispersed phase.
e.g., Sols of protein, starch
They are more stable and will not get precipitated readily.
They can be brought back to colloidal solution even after the precipitation by addition of dispersion medium
They arc called reversible sols

Lyophobic colloids

In lyophobic colloid no attractive force exists between dispersed phase and dispersed phase and dispersion medium.
e.g., sols of gold, silver
They are less stable and get precipitated readily
They cannot be produced again by adding the dispersion medium.
They are called irreversible sols.

Question 19.
Explain about dispersion mediu, dispersed phase and example of

foam,
emulsion
sol

Answer:

Question 20.
Explain about dispersion medium, dispersed phase and example of

solid foam
Gel
Solid sol.

Answer:

Question 21.
How would you prepare colloids of ink and graphite? (OR)
Answer:
Explain about mechanical ‘dispersion method.
1. Using a colloid mill, the solid is ground to colloidal dimension. Coarse dispersion The colloid mill consists of two metal plates rotating in opposite directions at very high speed of nearly 7000 revolution per minute.

2. The colloidal particles of required colloidal size is obtained by adjusting the distance between the two plates.

3. By this method, colloidal solutions of ink and graphite and prepared.

Question 22.
Explain about Bredic’s arc method (or) Electro dispersion method (or) How would you prepare colloids of noble metals?
Answer:
1. An electrical arc is struck between electrodes dispersed in water surrounded by ice. When a current of I amp! 100V is passed, an arc produced forms vapours of metal which immediately condense to from colloidal solution.

2. By this method, colloidal solution of many metals like copper, silver, gold. platinum can be prepared.

3. Alkali hydroxide is an added an stabilising agent for the colloid solution.

Question 23.
Explain about ultrasonic dispersion. (or) How would you prepare mercury colloid?
Answer:
1. Sound waves of frequency more than 20kHz (audible limit) could cause transformation of coarse suspension to colloidal solution.

2. Claus obtained mercury sol by subjecting mercury to sufficiently high frequency ultrasonic vibrations.

3. The ultrasonic vibrations produced by generator spread the oil and transfer the vibration to the vessel with mercury in water.

Question 24.
Explain the methods of preparation of colloids of

AS₂S₃
S.

Answer:
1. Double decomposition:
When hydrogen suiphide gas is passed through a solution of arsenic oxide, a yellow coloured arsenic sulphide is obtained as a colloidal solution.

2. Decomposition:
When few drops of an acid is added to a dilute solution of sodium thio sulphate, the insoluble free sulphur produced by the decomposition of sodium thiosuiphate accumulates into clusters which impart various colours blue, yellow and even red to the system depending on their growth within the size of colloidal dimensions.

Question 25.
Describe about

Dialysis
Electro dialysis.

Answer:
1. Dialysis:
Thomas Graham separated the electrolyte from a colloid using a semipermeable membrane. In this method, the colloidal solution is taken in a bag made up of semipermeable membrane. It is suspended in a trough of flowing water, the electrolytes diffuse out of the membrane and they are carried away by water. membrane and they are carried away by water.

2. Electro dialysis:
The presence of electric field increases the speed of removal of electrolytes from colloidal solution. The colloidal solution containing an electrolyte as impurity is placed between two dialysing membranes enclosed into two compartments filled with water.

When current is passed, the impurities pass into water compartment and get removed periodically. This process is faster than dialysis, as the rate of diffusion of electrolytes is increased by The application of electricity.

Question 26.
Explain about ultrafiltration.
Answer:
1. The pores of ordinary filter papers permit the passage of colloidal solutions. In ultrafilteration, the membranes are made by using collodion, cellophane or visiking.

2. Vhen a colloidal solution is filtered using such a filter, colloidal particles are separated on the filter and the impurities are removed as washings.

3. This process is quickened by application of pressure. The separation of sol particles from electrolyte by fikration through an ultrafilter is called ultrafiltration.

4. Collodian is 4% solution of nitrocellulose in a mixmre of alcohol and water.

Question 27.
Write a note about shape of colloidal particles.
Answer:
Colloidal particles possess various shapes.
Collidal particle

AS₂S₃
Fe(OH)₃ (blue gold sol)
W₃O₅ sol(tungstic acid sol)

Shape

Spherical
Disc (or) plate like
Rod like

Question 28.
What is meant by Tyndall effect? (or) Explain about the optical property of colloid.
Answer:
Answer:

Colloids have optical property. When a homogeneous solution is seen in the direction of light, it appears clear but it appears dark in a perpendicular direction.
When light passes through colloidal solution, it is scattered in all direction and it is known as Tyndall effect.
The colloidal particles absorbs a portion of light and remaining portion is scattered from the surface of the colloid. Hence the path of light is made clear.

Question 29.
What is meant by Brownian movement?
Answer:
1. Robert Brown observed that when the pollen grains suspended in water were viewed through an ultra microscope, they showed a random, zigzag, ceaseless motion. This is called Brownian movement of colloidal particles.

2. The colloidal sol particles are continuously bombard with the molecules of dispersion mediuri and hence they follow a zigzag. random, continuous movement.

Question 30.
Mention the uses of Brow nian movement.
Answer:
1. Brownian movement enables us to calculate Avogadro Number.

2. It is used to confirm kinetic theory which considers the ceaseles rapid movement of molecules that increases with increase in temperature.

3. It is used to understand the stability of colloids. As the particles are in continuous rapid movement, they do not come close and hence not get condensed. That is Brownian movement does not allow the particles to be acted on by force of gravity.

Question 31.
What is coagulation? Mention the method used to coagulate a colloid.
Answer:

The flocculation and setting down of the sol particles is called coagulation.
Various methods of coagulation are
addition of an electrolyte
Electrophoresis
mixing oppositely changed sols
boiling

Question 32.
The precipitation power of ions are in the order Al³⁺ > Ba²⁺ > Na⁺.
Similarly [Fe(CN)₆]^4-SO₄^2- Cl^–. Give the reason behind this.
Answer:
1. A negative ion causes the precipitation of positively changed sol and vice versa.

2. When the valency of ion is high, the precipitation power increased. So in cations the precipitation power order is Al³⁺ > Ba²⁺ > Na and in anions the precipitation power order is [Fe(CN)₆]^4- > SO₄^2- > Cl^–.

3. The precipitation power of electrolyte is determined by finding the minimum concentration required to cause precipitation of sol in 2hrs. This value is called flocculation value. The smaller the flocculation value, greater will be precipitation.

Question 33.
Explain how coagulation of colloid is carried out by

Flectrophoresis
By mixing two oppositely changed sols
By boiling.

Answer:
1. Electrophoresis:
In eleetrophoresis, charged particles migrate to the electrodes of opposite sign. It is due to neutralization of the charge of the colloids. The particles are discharged and sothey get precipitated.

2. By mixing two oppositely charged sols: When colloidal sols with opposite charges are mixed, mutual coagulation takes place. It is due to migration of ions from the surface of the particles.

3. By boiling – When colloidal sol is boiled, due to increased collisions, the sol particles combine and settle down.

Question 34.
Explain about protective action of colloid.
Answer:
1. Lyophobic sols are precipitated readily even with small amount of electrolytes. But they are stabilised by the addition of small amount of lyophillic colloid.

2. A small amount of gelatine sol is added to gold sol to protect gold sol.

3. Gold number is a measure of protecting power of a colloid, Gold number is defined as the number of milligrams of hydrophillic colloid that will just prevent the precipitation of 10ml of gold sol on the addition of imi of 10% NaG solution. Smaller the gold number, greater the protective power.

Question 35.
What are emulsions? Give its types. Explain with examples.
Answer:

Emulsions are colloidal solution in which a liquid is dispersed in another liquid.
There are two types of emulsions.
- Oil in water (0/W)
- Water in Oil (W/O)
Oil in Water : Oil dispersed in water. e.g., mayonnaise. icecrearn.
Water in Oil: Water dispersed in Oil. e.g., stiff grease, butter, cold cream.

Question 36.
Write 3 examples for emulsifiers.
Answer:

Most of the lyophillic colloids act as emulsifiers. Example, glue. gelatin.
Long chain compounds with polar groups like soap and suiphonic acid.
Insoluble powders like clay and lamp black also act as emulsifier,

Question 37.
What is meant by inversion of phase? Explain with example.
Answer:

The change of W/O emulsion into O/W emulsion is called inversion of phase.
Example: An oil in water emulsion containing potassium soap as emulsifying agent can be converted into water in oil emulsion by adding CaCl₂ (or) AlCl₃. This is called inversion of phase.

Question 38.
Write a note about medicinal applications of colloids.
Answer:

Antibodies such as penicillin and streptomycin are produced in colloidal form for suitable injections. They cure pneumonia.
Colloidal gold and colloidal calcium are used as tonics.
Milk of magnesia is used for stomach troubles.
Silver sol protected by gelatine known as Argyrol is used as eye lotion.

Question 39.
How colloids are used in

Tanning of leather
Rubber industry
Sewage disposal.

Answer:
1. Tanning of leather:
Skin and hides are protein containing positively charged particles which are coagulated by adding tannin to give hardened leather for further application. Chromium salts are used for tanning of leather. Chrome tanning can produce soft and polishable leather.

2. Rubber industry:
Latex is the emulsion of natural rubber with negative particles. By heating rubber with sulphur, vulcanized rubbers are produced for tyres, tubes etc.

3. Sewage disposal:
Sewage containing dirt, mud and wastes dispersed in water. Th e passage of electnic current deposits the wastes materials which can be used as a manure.

Question 40.
How would you distinguish natural honey from artificial honey?
Answer:

Natural honey is a colloidal sol. It is distinguished from artificial one by adding ammonia cal AgNO₃.
In the case of natural honey, a metallic silver is produced assumes a reddish yellow colour due to the traces of albumin or ethereal oil which acts as a protective colloid,
In case of artificial honey, a dark yellow (or) greenish yellow precipitate is formed.

Question 41.
Give four uses of emulsions.
Answer:

The cleansing action of soap is due to emulsions.
It is used in the preparation of vanishing cream.
It is used in the preparation of cod liver oiL.
It is used in the preparation of butter, cream etc.

Question 42.

Adsorption of a gas on the surface of solid is generally accompanied by a decrease in entropy. Still ¡t is a spontaneous process. Explain.
How does an increase in temperature affect both physical as well as chemical adsorption?

Answer:
1. According to the equation ∆G = ∆H – T∆S For a process to be spontaneous, ∆G should be negative. ∆H of adsorption is always negative. For a gas. ∆S is also negative. Thus, in an adsorption process, which is spontaneous, a. combination of these two factors always makes ∆G negative.

2. On increasing the temperature desorption occurs in case of physical adsorption. Chemical adsorption first increases and then decreases with increase in temperature.

Question 43.

What is the difference between a colloidal solution and an emulsion? Give one example of each.
What are emulsifiers?

Answer:
1. In a colloidal solution, the dispersed phase is a solid and the dispersion medium is liquid. In an emulsion, both the dispersed phase and the dispersion medium are liquid. Example – Colloidal sol — cell fluids, muddy water. Emulsion – milk, cold cream

2. Emulsifiers – The substance which are added to stabilise the emulsions are called emulsifiers. Example – Soaps of various kinds and lyophilic colloids (proteins, gum etc.)

Question 44.
Explain what is observed when.

KCl, an electrolyte, is added to an hydrated ferric hydroxide sol.
An electric current is passed through a colloidal solution.
A beam of light is passed through a colloidal solution.

Answer:

Feme hydroxide Fe(OH)₃ is a positively charged sol, so it gets coagulated by the chloride ions released from KCI solution.
When an electric current is passed through a colloidal solution due to charge on the colloidal particles they migrate towards the oppositely charged electrode.
When a beam of light is passed through a colloidal solution the path of light becomes visible.

Question 45.
Write three distinct differences between physical adsorption and chemisorption.
Answer:
Physical adsorption

Forces of attraction between the adsorbent and adsorbate molecules are weak Van der Waals’ forces,
Heat of adsorption is low (20-40 kJ mol¹)
It is temporary and reversible.

Chemical adsorption

Forces between the adsorbent and the adsorbate are strong chemical bond.
Heat of adsorption is high (80-24OkJ mol¹)
It is permanent and irreversible.

Question 46.
Explain the following observations.
Answer:

Lyophilic colloid is more stable than lyophobic colloid.
Coagulation takes place when sodium chloride solution added to a colloidal solution of ferric hydroxide.
Sky appears blue in colour.

Answer:
1. A lyophilic sol is stable duc to the charge and the hydration of the sol particles. Such a sol can only be coagulatd by removing the water and adding solvents like alcohol, acetone, etc. and then an electrolyte. On the other hand, a lyophobic soils stable due to charge only and hence it can he easily coagulated by adding small amount of an electrolyte.

2. The colloidal particles get precipitated. i.e., ferric hydroxide is precipitated.

3. The atmospheric particles of colloidal range scatter blue component of the white sunlight preferentially. That is why the sky appears blue.

Question 47.

Heat of adsorption is greater for chemisorption than physisorption. Why?
What is colloldion?
Differentiate between peptization and coagulation.

Answer:

Due to the formation of chemical bond between adsorbate and adsorbent.
4% solution of nitro cellulose in a mixture of alcohol and ether.
Peptisation is the process of converting a precipitate into colloidal sol by adding an electrolyte. Rut coagulation is the settling of colloidal particles.

Question 48.
Give reasons for the following.

Enzyme catalysts are highly specific in their action.
The path of light beconies visible wheti it is passed through As₂S₃ sol ¡n water.
The enthalpy in case of chemisorption is usually higher than that of physisorption.

Answer:

1. This is because each enzyme has a specific active site on which only a particular substrate can bind. ,

2. This is because of Tyndall effect caused due to the scattering of light by colloidal particles of As₂S₃ sol.

3. Chemisorption involves the formation ofa chemical bond between adsorbent and adsorbate molecule which involves high energy changes while in physisorption, the molecules of adsorbate and adsorbent arc held by weak van der Waals’ interactions.

Question 49.
What is adsorption? How does adsorption ola gas on a solid surface vary with pressure? Illustrate with the help of an appropriate graph.
Answer:
Adsorption is the phenomenon of attracting and retaining the molecules of a substance on the surface of a liquid or a solid, resulting in higher concentration of the molecules on the surface.

Effect of pressure:
At constant temperature, the adsorption of gas increases with increase of pressure of the gas. At low pressure. it increases rapidly. At an equilibrium pressure. the extent of adsorption (x/m) reaches its maximum value after which adsorption is independent of pressure.
$\frac{\mathrm{x}}{\mathrm{m}}=\mathrm{kP}^{1 / \mathrm{n}}$

Question 50.
How do size of particles of adsorbent, pressure of a gas and prevailing temperature influence of extent of adsorption of a gas on a solid?
Answer:
1. Effect of size of the particles of adsorbent: Greater the specific area of the solid available for adsorption of adsorbent, greater would be its adsorbing power. That is why porous or finely divided forms of adsorbents more strongly. However, the size of pores should be large enough to allow the diffusion of gas molecules.

2. Effect of pressure:
Increase in pressure initially increases the adsorption which later attains equilibrium at high pressure.
$\frac{\mathrm{x}}{\mathrm{m}}=\mathrm{kP}^{1 / \mathrm{n}}$ (n>1)

Samacheer Kalvi 12th Chemistry Surface Chemistry 5 Mark Questions and Answers

Question 1.
What is adsorption isotherm? Explain about Freundlich adsorption isotherm.
Answer:
1. Adsorption isotherms represents the variation of adsorption at constant temperature. Adsorption isoterm can be studied quantitatively.

2. A plot between the amount of adsorbate adsorbed and pressure or concentration of adsorbate at constant temperature is called adsorption isotherms.

3. Freundlich adsorption isotherm. According to Freundlich
$\frac{\mathrm{x}}{\mathrm{m}}=\mathrm{kP}^{1 / \mathrm{n}}$
Where x is the amount of adsorbate (or) adsorbed on ‘m’ gm of adsorbent at a pressure of P. k and n are constants. Value of’n’ is always less than unity.

4. This equation is applicable for adsorption of gases on solid surfaces. The Same equation becomes $\frac{\mathrm{x}}{\mathrm{m}}=\mathrm{kc}^{1 / \mathrm{n}}$ when used for adsorption in solutions with ‘c’ as concentration.

5. These equation quantitatively predict the effect of pressure (or concentration) on the adsorption of gases (or adsorbates) at constant temperature.

6. Taking log on both sides of equation
$\frac{\mathrm{x}}{\mathrm{m}}=\mathrm{kP}^{1 / \mathrm{n}}$
log $\frac { x }{ m }$ = log k + $\frac { 1 }{ n }$ log P

7. Hence the intercept represents the value of log k and the slope $\frac { b }{ q }$ gives $\frac { 1 }{ n }$

8. This equation explains the increase of with increase in pressure. But experimental values shows the deviation at low pressure.

9. Limitations:

This equation is purely empirical and valid over a limited pressure range.
The value of k and n also found vary with temperatures. No theoretical explanations were given.

Question 2.
Define catalyst. What are the characteristics of catalysts?
Answer:
A catalyst is defined as a substance which alters the rate of chemical reaction without itself undergoing chemical change.
Characteristics of catalyst:
1. For chemical reaction, catalyst is needed in very small quantity. Generally, a pinch of catalyst is enough for a reaction in bulk.

2. There may be some physical changes, but the catalyst remains unchanged in mass and chemical composition in a chemical reaction.

3. A catalyst itself cannot initiate a reaction. It means it cannot start a reaction which is not taking place. Rut, lithe reaction is taking place in a slow rate it can increase its rate.

4. A solid catalyst will be more effective if it is taken in a finely divided form.

5. A catalyst can catalyse a particular type of reaction, hence they are said to be specific in nature.

6. In an equilibrium reaction, presence of catalyst reduces the time for attainment of equilibrium and hence it does not affect the position
of equilibrium and the value of equilibrium constant.

7. A catalyst is highly effective at a particular temperature called as optimum temperature.

8. Presence of a catalyst generally does not change the nature of products.

9. For example 2SO₂ + O₂ → 2SO₃
This reaction is slow in the absence of a catalyst, but fast in the presence of Pt catalyst.

Question 3.
What is enzyme catalysis? Give the characteristics of enzyme catalysed reaction?
Answer:
Enzymes are complex protein molecules with three dimensional structures. They catalyse the chemical reaction in living organism. They are often present in colloidal state and extremely specific in catalytic action. This process is called enzyme catalysis.
Special characteristics of enzyme catalysis:
1. Effective and efficient conversion is the special characteristic of enzyme catalysed reactions. An enzyme may transform a million molecules of reactant in a minute.
For e.g., 2H₂O₂ → 2H₂O + O₂
For this reaction, activation energy is 1 8k.cal/mole without a catalyst. With colloidal platinum as a catalyst, the activation energy is 11.7 k.cal/mole. But with the enzyme catalyst. the activation energy of this reaction is less than 2 k.cal / mole.

2. Enzyme catalysis is highly specific in nature.
H₂N – CO – NH₂ + H₂O → 2NH₃ + H₂O
The enzyme urcase which catalyses the reaction of urea does not catalyse the hydrolysis of methyl urea (NH₂ – CO – NHCH₃)

3. Enzyme catalysed reaction has maximum rate at optimum temperature. At first rate of the reaction increases with increase of temperature, but above a particular temperature, the activity of enzyme is destroyed. The rate may even drop to zero. The temperature at which enzyrnic activity is high (or) maximum is called as optimum temperature. e.g., enzyme involved in human body have an optimum temperature 37°C / 98°F.

4. The rate of enzyme catalysed reactions varies with the pH of the system. The rate is maximum at a pH called optimum pH.

5. Enzymes can be inhibited i.e., poisoned. Activity of an enzyme is decreased and destroyed by a poison. The physiological action of drugs is related to their inhibiting action. e.g.. sulpha drugs, penicillin inhibits the action of bacteria and used for curing diseases like
pneumonia, dysentery, cholera.

6. Catalytic activity of enzymes is increased by coenzymes or activators. A small non protein (vitamin) called a coenzyme promotes the catalytic activity of enzyme.

Question 4.
Explain about phase transfer catalysis.
Answer:
1. Consider the reactant of a reaction is present in one solvent and the other reactant is present in an another solvent. The reaction between them is very slow, if the solvents are immisible.

2. As the solvents form separate phases, the reactants have to migrate across the boundary to react. But migration of reactants across the boundary is not easy. For such situation, a third solvent is added which is miscible with both. So, the phase boundary is eliminated the reactants freely mix and react fast.

3. But for large scale preparation of any product, use of a third solvent is not convenient as it may be expensive. For such problems, phase transfer catalysis provides a simple solution, which avoids the use of solvents.

4. it directs the use of a phase transfer catalyst (a phase transfer reagent) to facilitate transport of a reactant in one solvent to other solvent where the second reactant is present. As the reactants are now brought together, they rapidly react and form the product.

5. Example – Substitution of C1 and CN in the following reaction.

R Cl = 1 – chloro octane
R CN = 1 – cyano octane

6. By direct heating of two phase mixture of organic 1 – chioro Octane with aqueous sodium cyanide for several days, 1 – cyano octane is not obtained. However, if a small amount of quarternary ammonium salt like tetra alkyl ammonium cation which has hydrophobic and hydrophilic ends, transports CN – from the aqueous phase to the organic phase using its hydrophilic end and facilitates the reactions with 1 – chloro octane as shown below

7. So phase transfer catalyst, speeds up the reaction by transporting one reactant from one phase to another.

Question 5.
Explain about the classification of colloids based on the physical state of dispersed phase and dispersion medium with example.
Answer:

Question 6.
Describe about condensation methods of preparation of colloids. (OR) Describe chemical methods of preparation of colloids. When the substance for colloidal particle is present as smalL sized particle, molecule or ion, they are brought to the colloidal dimension by condensation methods.

Answer:
1. Oxidation method:
When hydroiodic acid is treated with iodle acid J, sol is obtained.
HIO₃ + 5HI → 3H₂O + 3I_2(sol)

2. Reduction method:
Gold sol is prepared by reduction of aune chloride using formaldehyde.
2 AuCl₃ + 3HCHO + 3H₂O → 2 Au_(sol) + 6HCI + 3HCOOH

3. Hydrolysis:
Ferric chloride is hydrolysed to get ferric hydroxide colloid
FeCl₃ + 3H₂O → Fe(OH)₃(sol) + 3HCI

4. Double decomposition:
When hydrogen suiphide gas is passed through a solution of arsenic oxide, a yellow coloured arsenic sulphide is obtained as a colloidal solution.
As₂O₃ – 3H₂S → As₂S₃ + 3H₂O

5. Decomposition:
When few drops of an acid is added to a dilute solution of sodium thiosulphate, sulphur colloid is produced by the decomposition of sodium thio sulphate.
S₂O₃^2- + 2H⁺ → S_(sol) + H₂O + SO₂

7. Describe about the properties of colloids.
Answer:
1. Colour:
The colour of a sol is not always the same as the colour of the substance in the bulk. For example, bluish tinge is given by diluted milk in reflected light and reddish tinge in transmitted light.

2. Size:
The size of colloidal particles ranges from Imp to 1pm diameter.

3. Colloidal solutions are heterogeneous in nature:
They have two distinct phases. Experiments like dialysis. ultrafiltration show the heterogeneous in nature but they are considered as borderline cases.

4. Filterability:
As the size of pores in ordinary filter paper are large, the colloidal particles easily pass through the ordinary filter papers.

5. Non setting nature:
Colloidal solutions are quite stable i.e., they are not affected by gravtiy.

6. Concentration and density:
When the colloidal solution is dilute, it is stable. When the volume of medium is decreased, coagulation occurs. Density of sol decreases with
decrease in the concentration.

7. Diffusability:
Unlike true solution, colloids diffuse less readily through membranes.

8. Colligative properties:
The colloidal solutions show colligative properties such as elevation of boiling point, depression in freezing point and osmotic pressure. These. properties are used to determine molecular weight of colloidal particles.

9. Shape of colloidal particles:
Colloidal particles have various shapes

Collidal particle

AS₂S₃
Fe(OH)₃ (blue gold sol)
W₃O₅ sol(tungstic acid sol)

Shape

Spherical
Disc (or) plate like
Rod like

10. Optical property:
The path of the light is visible when it is passes through a colloidal solution due to the scattering of light by colloidal particles. This is known as Tyndall effect.

11. Kinetic property:
When colloidal solution is viewed through an ultra microscope, they showed a random, zigzag ceaseless motion which is called Brownian movement.

12. Electrical property:
Helmholtz double layer. electrophoresis and electro osmosis are electrical properties of colloids.

Question 8.
Explain about Electrophoresis (or) Cataphoresis (or) How would you detect the presence of charges on sol particles? (or) Explain about the method used to detect the presence of charge on sol particles. Electrophoresis (or) cataphoresis:

Answer:
1. When electric potential is applied across two platinum electrodes dipped in a hydrophilic sol, the dispersed particles move toward one or other electrode. This migration of sol particles under the influence of electric field is called electrophoresis.

2. If the sol particles migrate to the cathode, then they possess positive charges and if the sol particles migrate to the anode, they have negative charges. Thus from the direction Afiet of migration of sol particles, we can determine the charge of the sol particles. Hence electrophoresis is used for the detection of presence of change on the sol particles.

3.
Positively charged coiloids

Fe(OH)₃, Al(OH)₃
Basic dyes, Haemoglobin

Negatively charged colloids

Ag, Au & Pt, AS₂S₃,
Clay, Starch

Question 9.
What are emulsion? Mention its type with example. What is emulsification? How the types of emulsions are identified?
Answer:
1. Emulsions arc colloidal solution in which a liquid dispersed in another liquid.

2. Two types of emulsions

Oil in Water (O/W) e.g., mayonnaise
Water in Oil (W/O) e.g., Butter

3. The process of preparation of emulsion by the dispersal of one liquid in another liquid is called emulsification.

4. Identification of types of emulsions. The two types of emulsions can be identified by the following tests

Dye test – A small amount of dye soluble in oil is added to emulsion. The emulsion is shaken well. The aqueous emulsion will not take the colour whereas oily emulsion will take up the colour of the dye.
Viscosity test – Viscosity of the emulsion is determined by experiments. Oily emulsions will have higher value than aqueous emulsions.
Conductivity test – Conductivity of aqueous solutions are always higher than oily emulsions.
Spreading test – Oily emulsions spread readily than aqueous emulsion when spread on an oily surface.

Question 10.
What is deeniulsification? Explain about the various techniques of deemulsification.
Answer:
Emulsion can be separated into two separate layers. This process is called Deemulsification. Various deemulsilication techniques are given below.

Distilling of one component
Adding an electrolyte to destroy the charge.
Destroying the emulsifier using chemical methods.
Using solvent extraction to remove one component.
By freezing one of the components.
By applying centrifugal force.
Adding dehydrating agents for water in oil type.
Using ultrasonic waves.
Heating at high pressures.

Question 11.

(a) How can a colloidal solution and a true solution of the same colour be distinguished from each other?
(b) List four applications of adsorption.

Answer:

The path of light becomes visible when passed through a colloidal solution while it is not visible in case of a true solution. This is because of Tyndall effect caused by the scattering of light by colloidal particles.
Applications of adsorption:
- Activated charcoal is used in gas masks to remove poisonous gases such as CH₄, CO, etc.
- Animal charcoal is used as decoloriser in the manufacture of sugar.
- Silica is used for removing moisture.
- The ion exchange resins are used for removing hardness of water.

Question 12.
Illustrate with examples.

Lyophilic and Lyophobic sols
Homogeneous and Heterogeneous catalysis.

Answer:
1. The substances such as proteins, starch, rubber, etc. directly passes into the colloidal state when brought in contact with the solvent. Such colloids are known as lyophillic sols, The substances like metals, their suiphides. hydroxides, etc. do not form colloidal sol readily when mixed with dispersion medium. The colloidal sols can only be prepared by some special methods. Such sols are called lyophobic sols.

2. Homogeneous catalysis:
Here the reactants and catalyst are present in the same phase. For example, lead chamber process for the manufacture of H₂SO₄.

Heterogeneous catalysis:
Here the reactants and catalyst are present in different phases. For example, contact process for manufacture of H₂SO₄.

Common Errors

Students may get confused with the words absorption and adsorption
There may be a confusion between physical adsorption and chemical adsorption
Catalyst poison and negative catalyst are different.
Colloids : There may be a doubt between dispersed phase and dispersion medium.
Electro dialysis, Electrophoresis, Electro osmosis may get confused.

Rectifications

1. In surface chemistry, we should use only adsorption. Adsorption mainly explains surface phenomenon.
Physical adsorption – Weak Vander walls forces, multilayer formation, Heterogenous catalysis.

2. Chemical adsorption:
Bond formation, mono-layer formation, Homogeneous catalysis.
Catalyst poison: decreases the catalytic activity of catalyst. Negative catalyst: reduces the rate of a chemical reaction.

3. Dispersion medium:
Larger in amount. Dispersed phase – Smaller in amount. Colloid is dispersed phase in dispersion

4. medium. For e.g., smoke is colloid in which carbon solid particles dispersed in air dispersion medium.
Electrodialysis – Purification of colloid by electric current.

5. Electrophoresis:
Movement of colloidal particles (dispersed phase) towards the oppositely charged electrode under the influence of electric current. Electro osmosis: Movement of dispersion medium towards the oppositely charged electrode under the influence of electric current.

Samacheer Kalvi 12th Bio Zoology Solutions Chapter 3 Reproductive Health

Tamilnadu Samacheer Kalvi 12th Bio Zoology Solutions Chapter 3 Reproductive Health

Samacheer Kalvi 12th Bio Zoology Reproductive Health Text Book Back Questions and Answers

Question 1.
Which of the following is correct regarding HIV, hepatitis B, gonorrhoea and trichomoniasis?
(a) Gonorrhoea is a STD whereas others are not.
(b) Trichomoniasis is a viral disease whereas others are bacterial.
(c) HIV is a pathogen whereas others are diseases.
(d) Hepatitis B is eradicated completely whereas others are not.
Answer:
(c) HIV is a pathogen whereas others are diseases.

Question 2.
Which one of the following groups includes sexually transmitted diseases caused by bacteria . only?
(a) Syphilis, gonorrhoea and candidiasis
(b) Syphilis, chlamydiasis and gonorrhoea
(c) Syphilis, gonorrhoea and trichomoniasis
(d) Syphilis, trichomoniasis and pediculosis
Answer:
(b) Syphilis, chlamydiasis and gonorrhoea

Question 3.
Identify the correct statements from the following:
(a) Chlamydiasis is a viral disease.
(b) Gonorrhoea is caused by a spirochaete bacterium, Treponema palladium.
(c) The incubation period for syphilis is 2 to 14 days in males and 7 to 21 days in females.
(d) Both syphilis and gonorrhoea are easily cured with antibiotics.
Answer:
(d) Both syphilis and gonorrhoea are easily cured with antibiotics.

Question 4.
A contraceptive pill prevents ovulation by
(a) blocking fallopian tube
(b) inhibiting release of FSH and LH
(c) stimulating release of FSH and LH
(d) causing immediate degeneration of released ovum.
Answer:
(b) inhibiting release of FSH and LH

Question 5.
The approach which does not give the defined action of contraceptive is

Answer:
(b) Vasectomy – Prevents spermatogenesis

Question 6.
Read the given statements and select the correct option.
Statement 1: Diaphragms, cervical caps and vaults are made of rubber and are inserted into the female reproductive tract to cover the cervix before coitus.
Statement 2: They are chemical barriers of conception and are reusable.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is correct but statement 2 is incorrect.
(d) Both statements 1 and 2 are incorrect.
Answer:
(c) Statement 1 is correct but statement 2 is incorrect.

Question 7.
Match column I with column II and select the correct the correct option from option the code given below

Answer:
(d) A – (iv), B – (i), C – (ii), D – (iii)

Question 8.
Select the incorrect action of hormonal contraceptive pills from the following
(a) Inhibition of spermatogenesis.
(b) Inhibition of ovulation.
(c) Changes in cervical mucus impairing its ability to allow passage and transport of sperms.
(d) Alteration in uterine endometrium to make it unsuitable for implantation.
Answer:
(a) Inhibition of spermatogenesis.

Question 9.
What is amniocentesis? Why a statutory ban is imposed on this technique?
Answer:
Amniocentesis is a prenatal technique used to detect any chromosomal abnormalities in the foetus and it is being often misused to determine the sex of the foetus. Once the sex of the foetus is known, there may be a chance of female foeticide. Hence, a statutory ban on amniocentesis is imposed.

Question 10.
Select the correct term from the bracket and complete the given branching tree

(Barriers, Lactational amonerrhoea, Tubectomy, CuT)
Answer:

Question 11.
Correct the following statements

Transfer of an ovum collected from a donor into the fallopian tube is called ZIFT.
Transfering of an embryo with more than 8 blastomeres into the uterus is called GIFT,
Multiload 375 is a hormone-releasing IUD.

Answer:

Transfer of 8 celled blastomere collected from donors into the fallopian tube is called ZIFT.
Transfering of an embryo with more than 8 blastomeres into uterus is called IUT.
Multiload 375 is a copper-releasing IUD.

Question 12.
Which method do you suggest the couple to have a baby, if the male partner fails to inseminate the female or due to very low sperm count in the ejaculate?
Answer:
Micro-testicular sperm extraction (TESE):
Microsurgical sperm retrieval from the testicle involves a small midline incision in the scrotum, through which one or both testicles can be seen. Under the microscope, the seminiferous tubules are dilated and small amount of testicular tissue in areas of active sperm production are removed and improved for sperm yield compared to traditional biopsy techniques.

Question 13.
Expand the following:

ZIFT
ICSI

Answer:

Zygote intrafallopian transfer
Intracytoplasmic sperm injection

Question 14.
What are the strategies to be implemented in India to attain total reproductive health?
Answer:

Creating awareness and providing medical assistance to build a healthy society.
Introducing sex education in schools to provide information about adolescence and adolescence related changes.
Educating couples and those in the marriageable age groups about the available birth control methods and family planning norms.
Creating awareness about care for pregnant women, post-natal care of mother and child, and the importance of breastfeeding.
Encouraging and supporting governmental and non-governmental agencies to identify new methods and/or to improve upon the existing methods of birth control.

Question 15.
Differentiate foeticide and infanticide.
Answer:
Female foeticide refers to ‘aborting the female in the mother’s womb’.
Female infanticide is ‘killing the female child after her birth’.

Question 16.
Describe the major STDs and their symptoms.
Answer:

Cervical cancer:
Cervical cancer is caused by a sexually transmitted virus called Human Papillomavirus (HPV). HPV may cause abnormal growth of cervical cells or cervical dysplasia. The most common symptoms and signs of cervical cancer are pelvic pain, increased vaginal discharge, and abnormal vaginal bleeding. The risk factors for cervical cancer include

Having multiple sexual partners
Prolonged use of contraceptive pills

Cervical cancer can be diagnosed by a Papanicolaou smear (PAP smear) combined with an HPV test. X-Ray, CT scan, MRI, and PET scan may also be used to determine the stage of cancer. The treatment options for cervical cancer include radiation therapy, surgery and chemotherapy.

Modem screening techniques can detect precancerous changes in the cervix. Therefore screening is recommended for women above 30 years once in a year. Cervical cancer can be prevented with vaccination. Primary prevention begins with HPV vaccination of girls aged 9-13 years before they become sexually active. Modification in lifestyle can also help in preventing cervical cancer. A healthy diet, avoiding tobacco usage, preventing early marriages, practicing monogamy and regular exercise minimize the risk of cervical cancer.

Question 17.
How are STDs transmitted?
Answer:
Sexually transmitted diseases (STD) are called Sexually transmitted infections (STI). Normally STI is transmitted from person to person during intimate sexual contact with an infected partner. Infections like Hepatitis-B and HIV are transmitted sexually as well as by sharing of infusion needles, surgical instruments, etc with infected people, blood transfusion or from infected mother to baby.

Question 18.
Write the preventive measures of STDs.
Answer:
Prevention of STDs:

Avoid sex with unknown partner/ multiple partners
use condoms
In case of doubt, consult a doctor for diagnosis and get complete treatment.

Question 19.
The procedure of GIFT involves the transfer of female gametes into the fallopain tube, can gametes be transferred to the uterus to achieve the same result? Explain.
Answer:
Gamete intra-fallopian transfer (GIFT):
Transfer of an ovum collected from a donor into the fallopian tube. In this the eggs are collected from the ovaries and placed with the sperms in one of the fallopian tubes. The zygote travels toward the uterus and gets implanted in the inner lining of the uterus.

Question 20.
Amniocentesis, the foetal sex determination test, is banned in our country. Is it necessary? Comment.
Answer:
Amniocentesis is a prenatal technique used to detect any chromosomal abnormalities in the foetus and it is being often misused to determine the sex of the foetus. Once the sex of ‘ the foetus is known, there may be a chance of female foeticide. Hence, a statutory ban on amniocentesis is imposed.

Question 21.
Open Book Assessment ‘Healthy reproduction, legally checked birth control measures and proper family planning programmes are essential for the survival of mankind’ Justify.
Answer:
Reproductive health and proper family planning programmes are highly essential for the survival of mankind. Reproductive health refers to the state of physical, psychological, and social well-being merely in absence of illness in all matters related to the reproductive system and its proper functioning. Family planning has the following health and social benefits.

Protecting the health of women by reducing frequent pregnancies.
Reducing abortions.
Providing stable population growth.
Assuming the infants well being by providing adequate time lapse between successive pregnancies.

Samacheer Kalvi 12th Bio Zoology Reproductive Health Additional Questions and Answers

1 – Mark Questions

Question 1.
Which of the following is Not a natural contraceptive?
(a) Rhythm method
(b) Lactational amenorrhoea
(c) Progestasert
(d) Continuous abstinence
Answer:
(c) Progestasert

Question 2.
Identify the fungal STD(s)
(i) Trichomoniasis
(ii) Genital herpes
(iii) Candidiasis
(a) Only (i)
(b) Only (iii)
(c) Only (iv)
Answer:
(b) Only (iii)

Question 3.
Match the following.

Answer:
(a) – iii, (b) – i, (c) – iv, (d) – ii

Question 4.
Pick out the incorrect statement regarding the character of a good contraceptive.
(a) It should be user friendly
(b) should not affect sexual drive
(c) side effects must be least
(d) should not be easily available
Answer:
(d) should not be easily available

Question 5.
Select the proper hormonal composition of oral contraceptive pills
(a) FSH & Prolactin (b) Prolactin & TSH
(c) TSH & FSH (d) FSH & LH
Answer:
(d) FSH & LH

Question 6.
Assertion (A): IUDs are inserted into the ovary.
Reason (R): IUD’s Increases phagocytosis of the sperm.
(a) Both A and R are correct
(b) Both A and R are incorrect
(c) A is correct R is incorrect
(d) A is incorrect R is correct
Answer:
(d) A is incorrect R is correct

Question 7.
Identify the mismatched pair.

Answer:
(c) Candidiasis (iii) Albugo candida

Question 8.
In India, a family planning programme was initiated in
(a) 1961
(b) 1981
(c) 1951
(d) 1971
Answer:
(c) 1951

Question 9.
Assertion (A): Amniocentesis helps to diagnose the chromosomal aberrations in foetus.
Reason (R): Amniocentesis is legalized in our country.
(a) Both A and R are wrong
(b) A is right and R is wrong
(c) R explains A
(d) A is the wrong R is right
Answer:
(b) A is right and R is wrong

Question 10.
Legalized marriageable age of female in India is
(a) 19 years
(b) 20 years
(c) 18 years
(d) 21 years
Answer:
(c) 18 years

Question 11.
Identify the correct statement.
(a) Lactational amenorrhea is a permanent birth control method
(b) Condoms are made of polyethylene glycol and lambskin
(c) LNG -20 is a copper – releasing IUD
(d) Diaphragm covers the cervix thereby preventing sperm entry
Answer:
(d) Diaphragm covers the cervix thereby preventing sperm entry

Question 12.
According to WHO, India is the largest HIV affected country.
(a) first
(b) second
(c) third
(d) seventh
Answer:
(e) third

Question 13.
Identify the correct statement.
(a) MTP is the voluntary killing of infant.
(b) MTP is legalized in India from 1974.
(c) Performing MTP during second trimester is riskier.
(d) It is a surgical – based abortion.
Answer:
(c) Performing MTP during second trimester is riskier.

Question 14.
Saheli, contains a non-steroidal preparation called
Answer:
Centchroman

Question 15.
The average foetal heartbeat rate is between beats per minute.
Answer:
120-160

Question 16.
World AIDS Day is observed on
Answer:
11th July

Question 17.
Indian Government legalized MTP in
Answer:
1971

Question 18.
In chorionic villus sampling test, the tissue sample is taken from
(a) amniotic fluid
(b) placental tissue
(c) Intestinal villi
(d) foetal liver
Answer:
(b) placental tissue

Question 19.
In ZIFT technique, the zygote is transferred at the stage of
(a) 16 blastomere
(b) morula
(c) 12 blastomere
(d) 8 blastomere
Answer:
(d) 8 blastomere

Question 20.
Given below are the basic steps in the IVF treatment cycle. Select the proper sequence.
(i) Ovarian stimulation
(ii)Egg retrieval
(iii) fertilization
(iv) Embryo culture
(v) Embryo transfer
(a) (ii) → (ii) → (v) → (i) → (iii)
(b) (i) → (iii) → (ii) → (v) → (iv)
(c) (i) → (ii) → (ii) → (iv) → (v)
(d) (ii) → (i) → (iii) → (v) → (iv)
Answer:
(c) (i) → (ii) → (ii) → (iv) → (v)

Question 21.
Enactment of _____ banned the identification of sex and to prevent the prenatal abortion.
(a) POGSOAct
(b) POTAAct
(c) PCPNDTAct
(d) GOONDAAct
Answer:
(c) PCPNDT Act

Question 22.
Which is NOT a national health care programme?
(a) Pradhan Mantri Surakshit Matritva Abhiyan
(b) Pradhan Mantri Fiscal BhimaYojana
(c) RMNCH + A approach
(d) Janani Shishu Suraksha Karyakaram
Answer:
(b) Pradhan Mantri Fiscal Bhima Yojana

Question 23.
______ is Known as anti-sterility vitamin.
Answer:
Vitamin-E

2 – Mark Questions

Question 1.
Name any four national level health care programmes run by the Indian Government.
Answer:

Janani Suraksha Yojana
Shishu Suraksha Karyakaram
RMNCH+A Programme
Pradhan Mantri Surakshit Matritva Abhiyan

Question 2.
Comment on ‘Saheli’
Answer:
Saheli is an oral contraceptive pill provided by Central Drug Research Institute in Lucknow, – India. It contains a non-steroidal hormone preparation called centchroman.

Question 3.
What is Mayer – Rokitansky Syndrome?
Answer:
All women are bom with ovaries, but some do not have functional uterus. This condition is called Mayer-Rokitansky syndrome.

Question 4.
Point out any four STDs caused by viruses.
Answer:

Genital herpes
Hepatitis-B
Genital warts
AIDS

Question 5.
Define Surrogacy.
Answer:
Surrogacy is a method of assisted reproduction or agreement whereby a woman agrees to carry a pregnancy for another person, who will become the newborn child’s parent after birth. Through In Vitro Fertilization (IVF), embryos are created in a lab and are transferred into the surrogate mother’s uterus.

Question 6.
Name the causative organism of

Syphilis
Genital warts

Answer:

Syphilis is caused by Treponema palladium
Genital warts caused by Human Papilloma vims.

Question 7.
Define Infertility.
Answer:
Inability to conceive or produce children even after unprotected sexual cohabitation is called infertility. That is, the inability of a man to produce sufficient numbers or quality of sperm to impregnate a woman or inability of a woman to become pregnant or maintain a pregnancy.

Question 8.
Expand the acronyms:

GIFT
ICSI

Answer:

GIFT – Gamete Intra – Fallopian Transfer.
ICSI – Intra Cytoplasmic Sperm Injection.

Question 9.
What is amniocentesis?
Answer:
Amniocentesis involves taking a small sample of the amniotic fluid that surrounds the foetus to diagnose chromosomal abnormalities.

Question 10.
How copper IUD’s provide contraception?
Answer:
Copper IUD’s release free copper and copper salts into the uterus and suppress sperm motility. They remain in the uterus for 5-10 years.
Eg: NovaT, Cu T-380.

Question 11.
What do you mean by the term – coitus interruptus?
Answer:
Coitus interruptus is the oldest family planning method, where the male partner withdraws his penis before ejaculation, thereby preventing the deposition of semen into vagina.

Question 12.
What is MTP?
Answer:
Medical Termination of Pregnancy (MTP) : Medical method of abortion is a voluntary or intentional termination of pregnancy in a non-surgical or non-invasive way. Early medical termination is extremely safe upto 12 weeks (the first trimester) of pregnancy and generally has no impact on a women’s fertility. Abortion during the second trimester is riskier as the foetus becomes intimately associated with the maternal tissue.

Question 13.
Which type of women are benefited by In Vitro Fertilization?
Answer:
IVF is used to treat women with blocked, damaged or absent fallopian tubes.

3 – Mark Questions

Question 1.
What are the steps taken by Government to overcome population explosion?
Answer:
To overcome the problem of population explosion, birth control is the only available solution.
People should be motivated to have smaller families by using various contraceptive devices. Advertisements by the Government in the media as well as posters/bills, etc., with a slogan Naam iruvar namakku iruvar (we two, ours two) and Naam iruvar namakku oruvar (we two, ours one) have also motivated to control population growth in Tamil Nadu. The statutory rising of marriageable age of the female to 18 years and that of males to 21 years and incentives given to couples with small families are the other measures taken to control population growth in our country.

Question 2.
Lactational amenorrhoea – Comment.
Answer:
Menstrual cycles resume as early as 6 to 8 weeks from parturition. However, the reappearance of normal ovarian cycles may be delayed for six months during breastfeeding. This delay in ovarian cycles is called lactational amenorrhoea. It serves as a natural, but an unreliable form of birth control.

Question 3.
Write a note on the sterilization procedure in the male.
Answer:
Vasectomy is the surgical procedure for male sterilisation. In this procedure, both vas deferens are cut and tied through a small incision on the scrotum to prevent the entry of sperm into the urethra. A vasectomy prevents sperm from heading off to the penis as the discharge has no sperms in it.

Question 4.
Define Tubectomy.
Answer:
Tubectomy is the surgical sterilisation in women. In this procedure, a small portion of both fallopian tubes are cut and tied up through a small incision in the abdomen or through vagina. This prevents fertilization as well as the entry of the egg into the uterus.

Question 5.
Complete the table by filling the gaps.

Answer:
A – Neisseria Gonorrhoea
B – AIDS
C- Jaundice

Question 6.
List various natural methods of birth control.
Answer:

Periodic abstinence
Coitus interruptus
Lactational amenorrhea

Question 7.
What does ICSI stand for? Describe the technique.
Answer:
ICSI stands for Intra-Cytoplasmic Sperm Injection. In this method, a sperm is carefully injected into the cytoplasm of the egg and the zygote formed is allowed to divide till 8 celled stage and transferred to uterus. Fertilization occurs in 75-85% of eggs injected with sperm.

Question 8.
How LNG-20 act as a contraceptive?
Answer:
LNG-20 is an Intra-Uterine System of contraceptive method. It increases the viscosity of cervical mucus and thereby preventing the sperms from entering the cervix.

Question 9.
MTP is legalized in our country. Yes or No? Why?
Answer:
Yes. The government of India legalized MTP in 1971 for medical necessity and social consequences ’with certain restrictions like sex discrimination and illegal female foeticides to avoid its misuse. MTP performed illegally by unqualified quacks is unsafe and could be fatal. MTP of the first conception may have serious psychological consequences

Question 10.
Write the hormonal composition of oral contraceptive pills. Also, explain their action mode.
Answer:
Oral contraceptive pills are enriched with synthetic progesterone and oestrogen hormones. These pills prevent ovulation by inhibiting the secretion of LH and FSH hormones.

Question 11.
Suggest some methods to help infertile couples to have children.
Answer:

Invitro fertilisation
Zygote intra-fallopian transfer (ZIFT)
Gamete intra-fallopian transfer (GIFT)
Surrogacy

Question 12.
What are the characteristics of a good contraceptive?
Answer:
An ideal contraceptive should be user-friendly, easily available, with the least side effects, and should not interfere with sexual drive.

Question 13.
Write is a note on a foetoscope.
Answer:
Foetoscope is used to monitor the foetal heart rate and other functions during late pregnancy and labour. The average foetal heart rate is between 120 and 160 beats per minute. An abnormal fetal heart rate or pattern may mean that the foetus is not getting enough oxygen and it indicates other problems. A hand-held doppler device is often used during prenatal visits to count the foetal heart rate. During labour, continuous electronic foetal monitoring is often used.

Question 14.
How the technique of amniocentesis is performed?
Answer:
Amniocentesis is generally performed in a pregnant woman between the 15th and 20th weeks of pregnancy by inserting a long, thin needle through the abdomen into the amniotic sac to withdraw a small sample of amniotic fluid. The amniotic fluid contains cells shed from the foetus.

Question 15.
Mention the role of prolactin in lactational amenorrhoea.
Answer:
Suckling by the baby during breastfeeding stimulates the pituitary to secrete increased prolactin hormone in order to increase milk production. This high prolactin concentration in the mother’s blood may prevent the menstrual cycle by suppressing the release of GnRH (Gonadotropin-Releasing Hormone) from the hypothalamus and gonadotropin secretion from the pituitary.

Question 16.
Name anyone

fungal STI
Bacterial STI
Protozoan STI

Answer:

Fungal STI – Candidiasis
Bacterial STI -Gonorrhoea
Protozoan STI – Trichomoniasis

Question 17.
Why ultrasonography is performed for carrying women?
Answer:
Ultrasonography is usually performed in the first trimester for dating, determination of the number of foetuses, and for assessment of early pregnancy complications.

Question 18.
Suggest any two simple precautions to avoid contracting RTFs.
Answer:

Avoiding coitus with unknown/multiple partners.
Use of condoms during coitus.

Question 19.
Name the most effective long-acting reversible contraceptive methods.
Answer:
Intrauterine devices and contraceptive implants.

5 – Mark Question

Question 1.
Give a detailed account of various natural methods of contraception.
Answer:
Natural method is used to prevent meeting of sperm with ovum, i.e., Rhythm method (safe period), coitus interruptus, continuous abstinence and lactational amenorrhoea.

a. Periodic abstinence/rhythm method: Ovulation occurs at about the 14th day of the menstrual cycle. Ovum survives for about two days and sperm remains alive for about 72 hours in the female reproductive tract. Coitus is to be avoided during this time.

b. Continuous abstinence is the simplest and most reliable way to avoid pregnancy is not to have coitus for a defined period that facilitates conception.

c. Coitus interruptus is the oldest family planning method. The male partner withdraws his penis before ejaculation, thereby preventing the deposition of semen into the vagina.

d. Lactational amenorrhoea: Menstrual cycles resume as early as 6 to 8 weeks from parturition. However, the reappearance of normal ovarian cycles may be delayed for six months during breast-feeding. This delay in ovarian cycles is called lactational amenorrhoea. It serves as a natural, but unreliable form of birth control.

Suckling by the baby during breastfeeding stimulates the pituitary to secrete increased prolactin hormone in order to increase milk production. This high prolactin concentration in the mother’s blood may prevent the menstrual cycle by suppressing the release of GnRH (Gonadotropin-Releasing Hormone) from the hypothalamus and gonadotropin secretion from the pituitary.

Question 2.
What are IUD’s? Explain its way of functioning. Also, describe their types.
Answer:
Intrauterine Devices (IUDs) are inserted by medical experts in the uterus through the vagina. These devices are available as copper releasing IUDs, hormone-releasing IUDs and non- medicated IUDs. IUDs increase the phagocytosis of sperm within the uterus. IUDs are the ideal contraceptives for females who want to delay pregnancy.

It is one of the popular methods of contraception in India and has a success rate of 95 to 99%. Copper releasing IUDs differ from each other by the amount of copper. Copper IUDs such as Cu T-380 A, Nova T, Cu 7, Cu T 380 Ag, Multiload 375, etc. release free copper and copper salts into the uterus and suppress sperm motility. They can remain in the uterus for five to ten years. Hormone-releasing IUDs such as Progestasert and LNG – 20 are often called as intrauterine systems (IUS). They increase the viscosity of the cervical mucus and thereby prevent sperms from entering the cervix. Non-medicated IUDs are made of plastic or stainless steel. Lippes loop is a double S-shaped plastic device.

Question 3.
Write in detail about cervical cancer.
Answer:
Cervical cancer is caused by a sexually transmitted virus called Human Papillomavirus (HPV). HPV may cause abnormal growth of cervical cells or cervical dysplasia.
The most common symptoms and signs of cervical cancer are pelvic pain, increased vaginal discharge and abnormal vaginal bleeding. The risk factors for cervical cancer include

Having multiple sexual partners
Prolonged use of contraceptive pills

Cervical cancer can be diagnosed by a Papanicolaou smear (PAP smear) combined with an HPV test. X-Ray, CT scan, MRI and a PET scan may also be used to determine the stage of cancer. The treatment options for cervical cancer include radiation therapy, surgery and chemotherapy. Modem screening techniques can detect precancerous changes in the cervix. Therefore screening is recommended for women above 30 years once in a year.

Cervical cancer can be prevented with vaccination. Primary prevention begins with HPV vaccination of girls aged 9-13 years, before they become sexually active. Modification in lifestyle can also help in preventing cervical cancer. Healthy diet, avoiding tobacco usage, preventing early marriages, practicing monogamy and regular exercise minimize the risk of cervical cancer.

Question 4.
List out the causes of fertility in human.
Answer:
Causes for male infertility:

Undescended tests and swollen veins in scrotum
Underdeveloped testes
Tight clothing increases the temperature in scrotum and affect sperm production.
Autoimmune response against own sperm.
Usage of alcohol, tobacco, marijuana drugs etc.

Causes for female infertility:

Malformation of cervix or fallopian tubes.
Inadequate nutrition at puberty.
Low body fat (anorexia = psychological eating disorder due to fear of gaining weight)
Pelvic Inflammatory Disease (PID), uterine disorders, endometriosis.
underdeveloped ovaries.
Developing antibodies against sperm.

Common Causes for both the sexes:

Tumours in pituitary or sex organs
Inherited mutation of hormone synthesizing genes
Long term stress
Ingestion of toxins (Cadmium) & drugs
Injuries to gonads
Ageing

Higher Order Thinking Skills (HOTs) Questions

Question 1.
Dr. Sheela is a famous Gynaecologist at Poes garden. However illegally she performed amniocentesis for several pregnant illiterates and did MTP if identified as female foetus, on request. Under which act will she get arrested, if a complaint is filed against her.
Answer:
Dr. Sheela will be be arrested under PCPNDT Act – preconception and prenatal diagnostic technique Act-1994.

Question 2.
Identify the picture and describe the surgical procedure.
Answer:
The picture describes tubectomy.

Tubectomy is the surgical sterilization in women.
In this, a portion of oviduct is cut and tied through vagina or minor incision in the abdomen.
It prevents fertilization and also the entry of egg to uterus.

Samacheer Kalvi 10th Social Science Model Question Paper 2 English Medium

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Students can Download Samacheer Kalvi 10th Social Science Model Question Paper 2 English Medium Pdf, Samacheer Kalvi 10th Social Science Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamil Nadu Samacheer Kalvi 10th Social Science Model Question Paper 2 English Medium

General Instructions:

The question paper comprises of four parts
You are to attempt all the questions in each part. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III and IV are to be attempted separately.
Question numbers 1 to 14 in Part I are Multiple Choice Questions of one mark each.
These are to be answered by writing the correct answer along with the corresponding option code and the corresponding answer
Question numbers 15 to 28 in Part II are of two marks each. Any one question should be answered compulsorily.
Question numbers 29 to 42 in Part III are of five marks each. Any one question should be answered compulsorily.
Question numbers 43 to 44 in Part IV are of Eight marks each. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 100

Part – I

Answer all the questions. Choose the correct answer [14 × 1 = 14]

Question 1.
Which country emerged as the strongest in East Asia towards the close of nineteenth century?
(a) China
(b) Japan
(c) Korea
(d) Mongolia
Answer:
(b) Japan

Question 2.
Who made peru as part of their dominions?
(a) English
(b) Spaniards
(c) Russian
(d) French
Answer:
(b) Spaniards

Question 3.
What was the name of the Samaj founded by Dayanand Saraswati?
(a) Arya Samaj
(b) Brahmo Samaj
(c) Prathana Samaj
(d) Adi Brahmo Samaj
Answer:
(a) Arya Samaj

Question 4.
Who had borrowed money from the East India Company to meet the expenses he had incurred during the Carnatic war?
(a) Velunachiyar
(b) Puli Thevar
(c) NawabofArcot
(d) Raja of Travancore
Answer:
(c) NawabofArcot

Question 5.
……………………..was the official newspaper of the Self-Respect Movement.
(c) Kudi Arasu
(b) Puratchi
(c) Viduthalai
(d) Paguththarivu
Answer:
(c) Kudi Arasu

Question 6.
The Southern most point of India is ……………..
(a) Andaman
(b) Kanyakumari
(c) Indira Point
(d) Kavaratti
Answer:
(c) Indira Point

Question 7
……………………is the highest gravity in India.
(a) Hirakud dam
(b) Bhakra Nangal dam
(c) Mettur dam
(d) Nagarjuna Sagar dam
Answer:
(b) Bhakra Nangal dam

Question 8.
The first Jute mill of India was established at ………………
(a) Gujarat
(b) Rajasthan
(c) Maharashtra
(d) Tamil Nadu
Answer:
(c) Maharashtra

Question 9.
Which of the following passes is not located in the Western Ghats of Tamil Nadu?
(a) Palghat
(b) Shencottah
(c) Bhorghat
(d) Achankoil
Answer:
(c) Bhorghat

Question 10.
Second staple food of the people of Tamil Nadu is…………………..
(a) Pulses
(b) Millets
(c) Oil seeds
(d) Rice
Answer:
(b) Millets

Question 11.
The Indian constitution gives to its citizens………………………
(a) Double citizenship
(b) Single citizenship
(c) Single citizenship in some states and double in others .
(d) None of the above
Answer:
(b) Single citizenship

Question 12.
The Agreement signed by India and China in 1954 related …………..
(a) Trade and Commerce
(b) Restoration of normal relations
(c) Cultural exchange programmes
(d) The Five Principles of Co-existence
Answer:
(d) The Five Principles of Co-existence

Question 13.
Which one sector is highest employment in the GDP?
are an essential aspect of a nation’s development.
(a) Agricultural Sector
(b) Industrial Sector
(c) Service Sector
(d) None of the above
Answer:
(c) Service Sector

Question 14.
………………are an essential aspect of a nation’s development.
(a) Agriculture
(b) Industry
(c) Railway
(d) None of these
Answer:
(a) Agriculture

Part – II

Answer any 10 questions. Question No. 28 is compulsory. [10 × 2 = 20]

Question 15.
Point out the essence of the Berlin Colonial Conference 1884-1885.
Answer:

The Berlin Colonial Conference of 1884-85 had that Africa should be divided into spheres of influence of various colonial powers.
The war between the British and Boers in South Africa, however, was in defiance of this
resolution.

Question 16.
Write a note on Third World Countries.
Answer:

The capitalist countries led by the US were politically designated as the First Worlds, while the communist states led by the Soviet Union came to be known as the Second World states, outside these two were called third World.
During the Cold War, third World consisted of the developing world the former colonies of Africa, Asia, and Latin America.
With the break up of the Soviet Union in 1991, and the process of globalisation, the term Third World has lost its relevance.

Question 17.
What do you mean by drain of wealth?
Answer:
The colonial economy was a continuous transfer of resources from India to Britain without any favourable returns back to India. This is called the drain to wealth.

Question 18.
Discuss the importance of Hindu Religious Endowment Act passed by the Justicite ministry ?
Answer:

Tamil Nadu has a large number of temples. These temples commanded huge resources which were monopolised and exploited by the dominant caste in the society and led to mismanagement of public resources.
The Justice Party introduced the Hindu Religious Endowment Act in 1926 and enabled any individual, irrespective of their caste affiliation, to become member of the temple committee and govern the resources of the religious institutions.

Question 19.
State the west flowing rivers of India.
Answer:

The Narmada and the Tapi are the west flowing rivers of the Peninsular India:
These rivers drain into the Arabian Sea.
These rivers form estuaries on the west coast.
These rivers are devoid of an large tributary system.
Narmada river is the largest among the west flowing rivers of peninsular India. Its principal tributaries are Bushner, Halon, Heran, Banjar, Dudhi, Shakkar, Tawa, Bama and Kolar.
Tapti river is one of only the three rivers in peninsular India that run from east to west. The others being the Narmada and the Mahi.
The major tributaries are Vaki, Gomai, Arunavati, Aner, Nesu, Buray Panjhra and Bori. It outfall into the Arabian sea through the Gulf of Cambay.

Question 20.
Write a note on Pipeline network transport in India.
Answer:

Pipelines are used for transporting crude oil, petroleum products and natural products and natural gas from oil fields to the refineries, factories and big thermal power plants.
Pipelines are more reliable and considerably safer mode of transportation.
The possibility of pilferage or product less on pipelines is almost negligible. The basic limitations of pipelines is that they are capital intensive mode of transportation.

Question 21.
How is coastal plain formed?
Answer:
It is formed by the rivers that flow towards east and drain in the Bay of Bengal.

Question 22.
What is MRTS?
Answer:
MRTS means mass Rapid Transport System and currently developing a Metro System, with its first underground stretch in operation since May 2017.

Question 23.
What is a Writ?
Answer:
A writ is an order or command issued by a Court in writing under its seal.

Question 24.
Write about India’s foreign policy.
Answer:
Nehru, India’s first Prime Minister, was opposed to the rivalry of the two superpowers (America and Russia). The aim of India’s foreign policy of that time was ‘world co-operation, world peace, end of colonial imperialism, racial equality and non-alignment’.

Question 25.
What is meant by Gross Domestic Product?
Answer:
The GDP is the market value of all the final goods and services produced in the country during a time period.

Question 26.
Write the types of globalization.
Answer:
There are three types of globalization –

Archaic globalization
Proto globalization and
Modem globalization.

Question 27.
Why we pay tax to the government?
Answer:
The levying of taxes aims to raise revenue to fund governance or to alter prices in order to affect demand. States and their functional equivalents throughout history have used money provided by taxation to carry out many functions.

Some of these include expenditures on economic infrastructure (transportation, sanitation, public safety, education, healthcare cur systems, to name a few), military, scientific research, culture and the arts, public works and public insurance and the operation of government itself. A government’s ability to raise taxes is called its fiscal capacity.

Question 28.
Name the states that lead in the production of iron ore in India.
Answer:
Jharkhand, Odisha, Chattisgarh, Karnataka, Andhra Pradesh and Tamil Nadu.

Part – III

Answer any 10 questions. Question No. 42 is compulsory. [10 × 5 = 50]

Question 29.
Fill in the blanks:
(i) Japan forced a war on China in the year ………………
(ii) The major tribal revolt took place in chota nagpur region was ……………
(iii) The Cauvery rises in hills of …………………. district in Karnataka.
(iv) Governor of the state government surrenders his resignation to
(v) A better economy introduce rapid development of the ……………….
Answers
(i) 1894
(ii) Kolrevolt
(iii) Coorg
(iv) President
(v) Capital market

Question 30.
Match the following:

Answer:

Question 31.
Match the following:

Answer:

Question 32.
(a) Distinguish between
(i) Himalayan Rivers and Peninsular Rivers.
(ii) Andaman and Nicobar Islands and Lakshadweep Islands.
Answer:
(a) (i) Himalayan Rivers and Peninsular Rivers

Himalayan Rivers:

Originate from Himalayas.
Long and wide Perennial in nature.
Perennial in nature.
Unsuitable for hydropower generation.
Middle and lower courses are navigable.

Peninsular Rivers:

Originate from Western Ghats.
Short and arrow.
Non Perennial in nature.
Suitable for hydropower generation.
Not useful for navigation.

(ii) Andaman and Nicobar Islands and Lakshadweep Islands
Andaman and Nicobar Islands :

They are located in the Bay of Bengal.
They are far off from India.
Port Blair is the capital.
They are about 572 islands.
Only 38 are inhabited.

Lakshadweep Islands:

They are located in the Arabian Sea.
They are of coral origin
Kavaratti is the administration headquaters.
They are 27 islands here.
Only 11 islands are inhabited.

(b) Give reason: The great Indian desert is called Marusthali.
Answer:
The Thar desert, also known as the Great Indian desert is a large arid region in the north western part of the Indian Subcontinent that covers an area of 2,00,000 Km2 and forms a natural boundary between India and Pakistan.

Marusthali means sand-dune. It covered eastern portion of the Great Indian Thar Desert in western Rajasthan. It extends over about 24,000 square miles north of the Luni River.

Question 33.
Attempt an essay on the Arab-Israeli wars of 1967 and 1973.
Answer:
(i) The formation of Palestinian Liberation Organisation (PLO) was never friendly to Israel. It came to be attached frequently by Palestinian guerrilla groups based in Syria, Lebanon and Jordan. Israel also made violent retaliation.

(ii) In November 1966, Israel attacked the village of Al-Sami in the Jordanian West Bank. The death toll in this attack was 18. In April 1967 Israel started air battle with Syria which resulted in the shooting down of six Syrian Mig fighter jet.

(iii) In his bid to show Egypt’s support for Syria, Nasser mobilised Egyptian forces in the Sinai, seeking the removal of UN emergency forces stationed there on May 18. On May 22, he closed the Gulf Aqaba to Israeli shifting.

(iv) On June 5, Israel stopped a sudden pre-emptive air strike that destroyed more than 90 percent of Egypt’s air force on the tarmac. A similar air assault was in capacitated the Syria air force. Within three ways, Israel captured the Gaza Strip and all the Senai Peninsula up to the East Bank of the Suez Canal.

(v) On June 7, the Israeli forces drove Jordanian forces out of East Jerusalem and most the West Bank. The War ended when the UN Security Council called for a ceasefire. Arab-Israel War of 1973: Egypt and Syria made a secret agreement in January 1973 to bring their armies under one command.

(vi) Hafez al-Assad, the President of Syria was keen on retrieving Golan Heights. As Assad was aware that his country’s weapons were dated, he offered the Israelis a peace deal of they would withdraw from Sinai. Israel rejected the offer.

(vii) Egypt and Syria then launched a sudden attack on the Yom Kippur religions holiday on 6 October 1973. Though Israel suffered heavy casualties, it could finally push back the Arab forces. But this time, due to UN intervention, Israel was forced to return to 1967 position. Arabs gained nothing out of this war too.

Question 34.
Estimate Periyar E.V.R’s decisive contribution to the social transformation of Tamil Nadu?
Answer:
Periyar was a great social reformer. His contribution to the social transformation of Tamil Nadu is really praise worthy.

He launched ‘Temple entry’ movement to provide the lower caste people easy access to the temples.
He also started the Self-Respect movement in 1925, with the determination that there ought to be ‘no God; no religion; no Gandhi; no Congress; and no Brahmins’.
Periyar was critical of patriarchy. He condemned child marriage and the Devadasi system. Right from 1929, when the Self-Respect conference began to voice its concern over the plight of women, Periyar had been emphasising on women’s right to divorce and property.
He advocated atheism as a mode of critique to deconstruct the established practices of faith, culture and custom. Periyar wanted religion to be replaced by rationalism.
He welcomed equal rights for males and females in property, guardianship and adoption. He was strong champion of birth control and contraception.

Question 35.
What is urbanization? Explain its impacts.
Answer:
The process of society’s transformation from rural to urban is known as urbanization. The level of urbanization of a place is assessed based on the size of population of the towns and cities and the proportion of population engaged in non agricultural sectors. These two are closely linked to the process of industrialization and expansion of the secondary and tertiary sectors of economy.

Impacts of urbanization:

Urbanization and population concentration go hand – in – hand and are closely related to each other. A rapid rate of urbanization in a society is taken as an indicator of its economic development.
Urbanization is increasing rapidly in the developing countries including India.
Rural to urban migration leads to population explosion in urban areas. Metropolitan cities like Mumbai, Kolkatta and Delhi have more population than that can accommodate.

The following are the major problem of urbanization in India:

It creates urban sprawl.
It makes overcrowding in urban centres.
It leads to shortage of houses in urban areas.
It leads to the formation of slums.
It increases traffic congestion in cities.
It creates water scarcity in cities.
It creates drainage problems.
It poses the problem of solid waste management.
It increases the rate of crime.

Question 36.
Write about Road Safety Rules.
Answer:

Aware of the road signals
Stop, look and cross
Listen and ensure whether a vehicle is approaching
Don’t rush on roads
Cross roads in pedestrian crossings
Don’t stretch hands while driving vehicles
Never cross road at bends and stay safe in a moving vehicle

Question 37.
What are the powers and functions of the Chief Minister?
Answer:
The powers and the functions of the Chief Minister are:

The Chief Minister is the head of the Council of Ministers. He recommends the persons who can be appointed as ministers by the Governor. He allocates the portfolio among the ministers.
He presides over the meetings of the council of Ministers and influences its decisions.
The Chief Minister is the principal channel of communication between Governor and the Council of Ministers.
He announces the Government policies on the floor of the House. He can introduce the Bills in the Legislative Assembly.
For smooth functioning of the State and for good Centre – State relations, he has to develop a rapport with the Union Government.

Question 38.
Explain the role of taxation in economic development.
Answer:
The role of taxation in developing economics is as follows.

1. Resource mobilisation: Taxation enables the government to mobilise a substantial amount of revenue. The tax revenue is generated by imposing direct taxes such as personal income tax and corporate tax and indirect taxes such as customs duty, excise duty, etc.

2 Reduction in equalities of income: Taxation follows the principle of equity. The direct
taxes are progressive in nature. Also certain indirect taxes, such as taxes on luxury goods, is also progressive in nature.

3. Social welfare: Taxation generates social welfare. Social welfare is generated due to higher taxes on certain undesirable products like alcoholic products.

4. Foreign exchange: Taxation encourages exports and restricts imports, Generally developing countries and even the developed countries do not impose taxes on export items.

5. Regional development: Taxation plays an important role in regional development, Tax incentives such as tax holidays for setting up industries in backward regions, which induces business firms to set up industries in such regions.

6. Control of inflation: Taxation can be used as an instrument for controlling inflation. Through taxation the government can control inflation by reducing the tax on the commodities.

Question 39.
Write briefly the history of globalization.
Answer:
The historical background of globalization can be discussed in three steps –
(i) Archaic Globalization – It is an early form of globalization. It existed during the Hellenistic Age. It established a trade link between the Roman Empire, Parthian Empire and the Han Dynasty. The commercial links between these powers inspired the development of the Silk Road. The Islamic Golden Age was also an important early stage of globalization.

(ii) Proto Globalization – It was characterised by the rise of maritime European empires in the 16th and 17th centuries. In the 17th century, globalization became private business phenomenon like British East India Company founded in 1600, described as the first multinational company.

(iii) Modern Globalization – The 19th and 20th centuries witnessed the advent of modem globalization. Global trade and capital investment increased. Several multinational firms came into being.

Question 40.
What are the contributions of Industrialization to development?
Answer:

(i) As stated earlier, it is essential to produce inputs to other producers in an economy. Even agriculture requires inputs from industry such as fertilisers and tractors to increase productivity.

(ii) Second, a market exists for both producers and consumer goods. Even services like banking, transport and trade are dependent on production of industrial goods.

(iii) Third, by using modem methods of production, industries contribute to better productivity and hence lower cost of production of all goods produced. It therefore helps people to buy goods at a cheaper rate and help create demand for more products.

(iv) Fourth, through such expansion of production, industrialisation helps to absorb the labour force coming out of agriculture. Employment generation is therefore an important objective of industrialisation.

(v) Fifth, a related advantage of industrialisation is therefore technological change. Through use of modem techniques, industrialisation contributes to learning of such methods and their improvement. As a result labour productivity, ie, output per unit of labour input increases, which can help workers earn higher wages.

(vi) Sixth, expanding incomes lead to more demand for goods and services. If an economy is not able to produce enough to meet such demand, it has to rely on imports and therefore spend a lot of foreign exchange. If the economy does not earn enough from exporting, it will be difficult to meet the growing demand. Industrialisation therefore helps an economy to save and also generate foreign exchange through exports. .

Question 41.
Draw a time line for the following:
five important events between 1889-1935.
Answer:
Samacheer Kalvi 10th Social Science Model Question Paper 2 English Medium – 5

Question 42.
Mark the following places on the world map.
(i) Great Britain
(ii) Russia
(iii) Hawai Island
(iv) Germany
(v) Norway
Answer:

Part – IV

Answer both questions. [2 × 8 = 16]

Question 43.
(a) Japanese Aggression in South-east Asia
(i) Name the South-east Asian countries which fell to the Japanese.
(ii) Account for the setback of Allies in the Pacific region?
(iii) What is the significance of Battle of Midway?
(iv) What happened to the Indians living in Burma?
Answer:
(a) Japanese Aggression in South-east Asia:

(i) Guam, the Philippines, Hong Kong, Singapore, Malaya, the Dutch East Indies (Indonesia) and Burma.
(ii) The Allies faced many reverses in the Pacific region because of their inadequate preparations. The colonial rulers, especially the British, withdrew from their territories, leaving the local people to face the atrocities of the Japanese.
(iii) The US navy defeated the Japanese navy in the Battle of Midway.
(iv) Many Indians walked all the way from Burma to the Indian border, facing hardships. Many died of disease and exhaustion. Those who remained suffered under the Japanese.

(b) Aligarh Movement
(i) What is the main aim of this movement? ‘
(ii) Who is considered the soul of this movement?
(iii) Why were English books translated into Urudu?
(iv) Name the college which was later raised to the status of a University?
Answer:
(b) Aligarh Movement:

(i) The main aim of the Aligarh Movement was to persuade the Muslims to acquire modem knowledge and English language.
(ii) Sir Sayed Ahmed Khan is considered the soul of the Aligarh Movement.
(iii) Many English Books were translated into Urdu in order to enable the Muslims to accept the western science and take up government services.
(iv) Aligarh Muhammadan Anglo-Oriental College.

[OR]

Question 43.
(c) Factors leading to the rise of National Movement.
(i) How did the national leaders inspire the people?
(ii) When was the Vernacular Press Act passed?
(iii) What was the policy of the British?
(iv) How did the British consider the Indians?
Answer:
(c) Factors leading to the rise of National Movement:

(i) They inspired the people with the ideas of self-respect and self-confidence.
(ii) The Vernacular Press Act was passed in 1878.
(iii) The British followed the policy of “Divide and Rule”.
(iv) The British considered the Indians as inferior and uncivilized.

(d) Maraimalai Adigal
(i) Name the Sangam texts for which Maraimalai Adigal wrote commentaries.
(ii) Name the journal where he worked as a young man.
(iii) Why did he oppose imposition of Hindi?
(iv) Who were the key influences in Maraimalai Adigal’s life?
Answer:
(d) Maraimalai Adigal

(i) Pattinappalai and Mullaipattu.
(ii) Siddhanta Deepika
(iii) Adigal promoted the use of pure Tamil words and removal of the Sanskrit influences from Tamil language. He painted out that Tamil language would suffer with the introduction of Hindi.
(iv) His teachers P. Sundaram Pillai and Somasundara Nayagar were the key influences in Maraimalai Adigal’s life.

Question 44.
Mark the following places on the given outline map of India.
(i) Zaskar range
(ii) River Ganga
(iii) Baghelkhand Plateau
(iv) Coffee growing area
(v) Any one Iron ore production area
(vi) Bombay high
(vii) Andaman & Nicobar Island
(viii) Cotton growing area
Answer:

[OR]

Mark the following places on the given outline map of Tamil Nadu:
(i) Red soil area
(ii) Mangrove forest
(iii) Villupuram
(iv) One oil seeds area
(v) Udagamandalam
(vi) Kancheepuram
(vii) Gomukhi dam
(viii) River Tamirabarani
Answer:

Map for Q. 42
(i) Great Britain
(ii) Russia
(iii) Hawai Island
(iv) Germany
(v) Norway
Answer:

Map for Q. 44
(i) Zaskar range
(ii) River Ganga
(iii) Baghelkhand Plateau
(iv) Coffee growing area
(v) Any one Iron ore production area
(vi) Bombay high
(vii) Andaman & Nicobar Island
(viii) Cotton growing area
Answer:

Map for Q. 44
(i) Red soil area
(ii) Mangrove forest
(iii) Villupuram
(iv) One oil seeds area
(v) Udagamandalam
(vi) Kancheepuram
(vii) Gomukhi dam
(viii) River Tamirabarani
Answer:

Samacheer Kalvi 10th Maths Model Question Paper 2 English Medium

Leave a Comment / Class 10 / By Prasanna

Students can Download Samacheer Kalvi 10th Maths Model Question Paper 2 English Medium Pdf, Samacheer Kalvi 10th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Maths Model Question Paper 2 English Medium

Instructions

The question paper comprises of four parts.
You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III and IV are to be attempted separately.
Question numbers 1 to 14 in Part I are Multiple Choice Quèstions of one-mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and.writing the option code and the corresponding answer.
Question numbers 15 to 28 in Part II àre two-marks questions. These are to be answered in about one or two sentences.
Question numbers 29 to 42 in Part III are five-marks questions. These are to be answered in about three to five short sentences.
Question numbers 43 to 44 in Part IV are eight-marks questions. These are to be answered in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Max Marks: 100

PART-I

I. Choose the correct answer. Answer all the questions. [14 × 1 = 14]

Question 1.
Let f and g be two functions given by f = {(0,1),(2,0),(3,-4),(4,2),(5,7)} g = {(0,2),(1, 0),(2,4),(-4,2),(7, 0)} then the range of fog is …………. .
(1) {0,2,3,4,5}
(2) {-4,1,0,2,7}
(3) {1,2,3,4,5}
(4) {0,1,2}
Answer:
(4) {0,1,2}

Question 2.
An A.P consists of 31 terms. If its 16^th term is m, then the sum of all the terms of this A.P. is …………. .
(1) 16m
(2) 62 m
(3) 31m
(4) $\frac{31}{2}$m
Answer:
(3) 31m

Question 3.
The value of (1³ + 2³ + 3³ +….+ 15³) – (1 + 2 + 3 +….+ 15) is …………. .
(1) 14400
(2) 14200
(3) 14280
(4) 14520
Answer:
(3) 14280

Question 4.
Which of the following should be added to make x⁴ + 64 a perfect square …………. .
(1) 4x²
(2) 16x²
(3) 8x²
(4) -8x²
Answer:
(2) 16x²

Question 5.
The number of points of intersection of the quadratic polynomial x² + 4x + 4 with the X axis is …………. .
(1) 0
(2) 1
(3) 0 or 1
(4) 2
Answer:
(2) 1

Question 6.
In the adjacent figure ∠BAC = 90° and AD ⊥BC then …………. .

(1) BDCD = BC²
(2) AB.AC = BC²
(3) BD.CD = AD²
(4) AB.AC = AD²
Answer:
(3) BDCD = AD²

Question 7.
If (5, 7), (3, p) and (6, 6) are collinear, then the value of p is …………. .
(1) 3
(2) 6
(3) 9
(4) 12
Answer:
(3) 9

Question 8.
(1 + tan θ + sec θ) (1 + cot θ – cosec θ) is equal to …………. .
(1) 0
(2) 1
(3) 2
(4) -1
Answer:
(3) 2

Question 9.
The total surface area of a cylinder whose radius is $\frac{1}{3}$ of its height is
(1) $\frac{9 \pi h^{2}}{8}$ sq. units
(2) 24πh² sq. units
(3) $\frac{8 \pi h^{2}}{9}$ sq. units
(4) $\frac{56 \pi h^{2}}{9}$ sq. units
Answer:
(3) $\frac{8 \pi h^{2}}{9}$ sq. units

Question 10.
The mean of 100 observations is 40 and their standard deviation is 3. The sum of squares of all deviations is …………. .
(1) 40000
(2) 160900
(3) 160000
(4) 30000
Answer:
(2) 160900

Question 11.
The probability a red marble selected at random from a jar containing p red, q blue and r green marbles is …………. .
(1) $\frac{q}{p+q+r}$
(2) $\frac{p}{p+q+r}$
(3) $\frac{p+q}{p+q+r}$
(4) $\frac{p+r}{p+q+r}$
Answer:
(1) $\frac{q}{p+q+r}$

Question 12.
If there are 28 relation from a set A = {2,4, 6, 8} to a set B, then the number of elements in B is …………. .
(1) 7
(2) 14
(3) 5
(4) 4
Answer:
(1) 7

Question 13.
If a₁ ,a₂, a₃ ……….. are in A.P. such that $\frac{a_{4}}{a_{7}}=\frac{3}{2}$, then the 13th term of the AP is …………. .
(1) $\frac{3}{2}$
(2) 0
(3) 12a₁
(4) 14a₁
Answer:
(2) 0

Question 14.
The X-intercept of the line 2x – 3y + 5 = 0 is …………. .
(1) $\frac{5}{2}$
(2) $\frac{-5}{2}$
(3) $\frac{2}{5}$
(4) $\frac{-2}{5}$
Answer:
(2) $\frac{-5}{2}$

PART-II

II. Answer any ten questions. Question No. 28 is compulsory. [10 × 2 = 20]

Question 15.
A function f is defined by f(x) = 3 – 2x. Find x such that f(x²) = (f (x))².
Answer:
f(x) = 3 – 2x
f(x²) = 3 – 2 (x²)
= 3 – 2x²
(f(x)² = (3 – 2x)²
= 9 + 4x² – 12x
But f(x²) = (f(x))²
3 – 2x² = 9 + 4x² – 12x
– 2x² – 4x² + 12x + 3 – 9 = 0
– 6x² + 12x – 6 = 0
(÷ by – 6) ⇒ x² – 2x + 1 = 0
(x – 1)(x – 1) = 0
x – 1 = 0 or x – 1 = 0
x = 1
The value of x = 1

Question 16.
If f(x) = x² – 1, g(x) = x – 2 find a, if gof (a) = 1.
Answer:
f(x) = x² – 1 ; g(x) = x – 2
gof = g [f(x)]
= g(x² – 1)
= x² – 1 – 2
= x² – 3
given gof (a) = 1
a² – 3 = 1 [But gof(x) = x² – 3]
a² = 4
a = √4 = ± 2
The value of a = ± 2

Question 17.
Find the number of integer solutions of = 1 (mod 15).
Answer:
3x ≡ 1 (mod 15) can be written as
3x – 1 = 15k for some integer k
3x = 15k + 1
x = $\frac{15 k+1}{3}$ = 5k + $\frac{1}{3}$
Since 5k is an integer, 5k + $\frac{1}{3}$ cannot be an integer. So there is no integer solution.

Question 18.
Find the rational form of the number $0 . \overline{123}$
Answer:
Let x = $0 . \overline{123}$
= 0.123123123 ….
= 0.123 + 0.000123 + 000000123 + ….
This is an infinite G.P
Here a = 0.123, r = $\frac{0.000123}{0.123}$ = 0.001
S_n = $\frac{a}{1-r}=\frac{0.123}{1-0.001}=\frac{0.123}{0.999}$
S_n = $\frac{41}{333}$

Question 19.
Find the GCD of 12(x⁴ – x³), 8(x⁴ – 3x³ + 2x²) whose LCM is 24x³ (x – 1)(x – 2)
Answer:

p(x) = 12(x⁴ – x³)
= 12x³(x – 1)
g(x) = 8(x⁴ – 3x³ + 2x²)
= 8x²(x² – 3x + 2)
= 8x²(x – 2) (x – 1)
L.C.M = 24x³(x – 1) (x – 2)
G.C.D = $\frac{p(x) \times g(x)}{\text { L.C.M. }}$
= $\frac{12 x^{3}(x-1) \times 8 x^{2}(x-2)(x-1)}{24 x^{3}(x-1)(x-2)}$
G.C.D = 4x²(x – 1)

Question 20.
Find the square root of the polynomial x⁴ – 12x³ + 42x² – 36x + 9 by division method
Answer:

$\sqrt{x^{4}-12 x^{3}+42 x^{2}-36 x+9}$ = |x² – 6x + 3|

Question 21.
Write expression $\frac{\alpha+3}{\beta}+\frac{\beta+3}{\alpha}$ interms of α + β and αβ.
Answer:

Question 22.
In the given diagram show that ∆PST ~ ∆PQR
Answer:

In ∆PST and ∆PQR,
$\frac{P S}{P Q}=\frac{2}{2+1}=\frac{2}{3}$ , $\frac{P T}{P R}=\frac{4}{4+2}=\frac{2}{3}$
Thus, $\frac{P S}{P Q}=\frac{P T}{P R}$ and ∠P is common
Therefore, by SAS similarity,
∆PST ~ ∆PQR

Question 23.
Find the value of for which the given points (2,3), (4, a) and (6, -3) are collinear.
Answer:
Let the points be A (2, 3), B(4, a) and C(6, -3).
Since the given points are collinear.
Area of a triangle =0

$\frac { 1 }{ 2 }$ [(x₁y₁ + x₂y₂ + x₃y₁) – (x₂y₁ + x₃y₂ + x₁y₃)] = 0
$\frac { 1 }{ 2 }$ [(2a – 12 + 18) – (12 + 6a – 6)] = 0
2a + 6 – (6 + 6a) = 0
2a + 6 – 6 – 6a = 0
-4 a = 0 ⇒ a = $\frac { 0 }{ 4 }$ = 0
The value of a = 0

Question 24.
The horizontal distance between two buildings is 70 m. The angle of depression of the top of the first building when seen from the top of the second building is 45°. If the height of the second building is 120 m, find the height of the first building.
Answer:

Let the height of the first building AD be “x” m
∴ EC = 120 – x
In the right ∆ CDE,
tan 45° = $\frac{C E}{C D}$
1 = $\frac{120-x}{70}$ ⇒ 70 = 120 – x
x = 50m
∴ The height of the first building is 50 m

Question 25.
If the coefficient of variation of a collection of data is 57 and its standard deviation is 6,84, then find the mean.
Answer:
Given coefficient of variation =57
Standard deviation (σ) = 6.84
C.V = $\frac{\sigma}{\bar{x}}$
57 = $\frac{6.84}{\bar{x}} \times 100$
x̄ = $\frac{6.84}{57} \times 100=\frac{684}{57}=12$
∴ Arithmetic mean x̄ = 12

Question 26.
The radius and height of a cylinder are in the ratio 2:7. If the curved surface area of the cylinder is 352 sq.cm. Find its radius.
Answer:
Let the radius be “2x” and the height be “7x”
Curved surface area = 352cm²
2πrh = 352
2 × $\frac{22}{7}$ × 2x × 7x = 352
44 × 2x² = 352
x² = $\frac{352}{44 \times 2}=\frac{176}{44}=4$
x = √4 = 2
Radius of the cylinder (2 × 2) = 4 cm

Question 27.
A number is selected at random from integers 1 to 100. Find the probability that it is not a perfect cube.
Answer:
Sample space = {1, 2, 3,…. 100}
n(S) = 100
Let A be the event of getting a perfect cube.
A = (1, 8, 27, 64)
n(A) = 4
p(A) = $\frac{n(\mathrm{A})}{n(\mathrm{S})}$
p(A) = $\frac{4}{100}=\frac{1}{25}$
The Probability that the selected number is not a perfect cube is
P(Ā) = 1 – P(A)
= 1 – $\frac{1}{25}$
= $\frac{24}{25}$

Question 28.
Find the value of k if 1³ + 2³ + 3³ + ……… + k³ = 2025
Answer:
1³ + 2³ + 3³ + ……… + k³ = 2025
$\left[\frac{k(k+1)}{2}\right]^{2}$ = 2025
$\frac{k(k+1)}{2}$ = $\sqrt{2025}$ = 45
k² + k = 90
K² + k – 90 = 0
(k + 10) (k + 9) = 0
k = -10 or k = 9 k = 9 (k = -10) is not possible
∴ The value of k = 9

Part – III

III. Answer any ten questions. Question No. 42 is compulsory. [10 × 5 = 50]

Question 29.
Let A = The set of all natural numbers less than 8, B = The set of all prime numbers less than 8, C = The set of even prime number. Verify that A × (B – C) = (A × B) – (A × C)
Answer:
A= {1,2, 3, 4, 5,6, 7}; B = {2, 3, 5,7} and C= {2}
B – C = {2, 3, 5, 7} – {2}
= {3,5,7}
A × (B – C) = {1,2, 3,4, 5,6,7} × {3, 5,7}
= {(1,3) (1, 5) (1, 7) (2, 3) (2, 5) (2, 7) (3,3) (3, 5) (3, 7) (4, 3) (4, 5) (4, 7) (5,3) (5, 5) (5, 7) (6, 3) (6, 5) (6, 7) (7, 3) (7, 5) (7, 7)} …. (1)

A × B = {1,2, 3,4, 5,6,7} × {2, 3, 5,7}
= {(1,2) (1, 3) (1, 5) (1, 7) (2, 2) (2, 3) (2, 5) (2, 7) (3, 2) (3, 3) (3, 5) (3, 7) (4,2) . (4, 3) (4, 5) (4, 7) (5, 2) (5, 3) (5, 5) (5, 7) (6, 2) (6, 3) (6, 5) (6, 7) (7, 2) (7, 3) (7, 5) (7, 7)}

A × C = {1,2, 3, 4, 5, 6, 7} × {2}
= {(1, 2) (2, 2) (3, 2) (4, 2) (5, 2) (6, 2) (7, 2)}

(A × B) – (A × C) = {(1, 3) (1, 5) (1, 7) (2, 3) (2, 5) (2, 7) (3, 3) (3, 5) (3, 7) (4, 3) (4, 5) (4, 7) (5, 3) 5, 5) (5, 7) (6, 3) (6, 5) (6, 7) (7, 3) (7, 5) (7, 7)} ….(2)
From (1) and (2) we get
A × (B – C) = (A × B) – (A × C)

Question 30.
If f(x) = x – 4, g(x) = x² and h(x) = 3x – 5 prove that fo(goh) = (fog)oh
Answer:
f(x) = x – 4; g(x) = x²; h(x) = 3x – 5
fog (x) = f[g(x)]
= f(x²)
= x² – 4
(fog) oh(x) = fog[h(x)]
= fog (3x – 5)
= (3x – 5)² – 4
= 9x² – 30x + 25 – 4
= 9x² – 30x + 21 …. (1)
goh(x) = g[h(x)]
= g(3x – 5)
= (3x – 5)²
= 9x² + 25 – 30x
fo(goh) x = f[goh(x)]
= f [9x² – 30x + 25]
= 9x² – 30x + 25 – 4
= 9x² – 30x + 21 ….(2)
Fróm (1) and (2) we get (fog)oh = fo(goh)

Question 31.
In an A.P., sum of four consecutive terms is 28 and their sum of their squares is 276. Find the four numbers.
Answer:
Let us take the four terms in the form (a – 3d), (a – d), (a + d) and (a + 3d).
Since sum of the four terms is 28,
a – 3d + a – d + a + d + a + 3d = 2%
4a = 28 gives a = 7
Similarly, since sum of their squares is 276,
(a – 3d)² + (a – d)² + (a + d)²+ (a + 3d)² = 276.
a² – 6ad + 9d² + a² – 2ad + d² + a² + 2ad + d² + a² + 6ad + 9d² = 276
4a² + 20d² = 276 ⇒ 4(7)² + 20d² = 276.
d² = 4 gives d = ± 2
If d = 2 then the four numbers are 7 – 3(2), 7 – 2, 7 + 2, 7 + 3(2)
That is the four numbers are 1, 5, 9 and 13.
If a = 7, d = -2 then the four numbers are 13, 9, 5 and 1
Therefore, the four consecutive terms of the A.P. are 1, 5, 9 and 13.

Question 32.
If a, b, c are three consecutive terms of an A.P. and x, y, z are three consecutive terms of a G.P. then prove that x^{b – c} × y^{c – a} × z ^{a – b} = 1.
Answer:
a, b, c are three consecutive terms of an A.P
∴ a = a, b = a + d and c = a + 2d respectively ……. (1)
x, y, z are three consecutive terms of a G.P
∴ x = x, y = xr, z = xr² respectively ….(2)
L.H.S = x^{b – c} × y^{c – a} × z ^{a – b}
( Substitute the values from 1 and 2 we get)

L.H.S = R.H.S
Hence it is proved

Question 33.
There are 12 pieces of five, ten and twenty rupee currencies whose total value is ₹105. But when first 2 sorts are interchanged in their numbers its value will be increased by ₹20. Find the number of currencies in each sort.
Answer:
Let the number of ₹5 currencies be “x”
Let the number of ₹10 currencies be “y”
and the number of ₹20 currencies be “z”
By the given first condition
x + y + z = 12 …….. (1)
By the given second condition
5x + 10y + 20z = 105
x + 2y + 4z = 21 (÷5) …….. (2)
By the given third condition
10x + 5y + 20z = 105 + 20
10x + 5y + 20z = 125
2x + y + 4z = 25 ………. (3)

Substituting the value of x = 7 in (5)
7 – y = 4 ⇒ – y = 4 – 7
-y = -3 ⇒ y = 3
Substituting the value of x = 7, y = 3 in …. (1)
7 + 3 + z = 12
z = 12 – 10 = 2
x = 7,y = 3,z = 2
Number of currencies in ₹ 5 = 7
Number of currencies in ₹ 10 = 3
Number of currencies in ₹ 20 = 2

Question 34.
Find the square root of the expression $\frac{4 x^{2}}{y^{2}}+\frac{20 x}{y}+13-\frac{30 y}{x}+\frac{9 y^{2}}{x^{2}}$
Answer:

Question 35.
If A = $\left[ \begin{matrix} 3 & 1 \\ -1 & 2 \end{matrix} \right]$ show that A² – 5A + 7I₂ = 0
Answer:

L.H.S = R.H.S
∴ A² – 5A + 7I₂ = 0

Question 36.
State and prove Thales theorem
Answer:
A straight line drawn parallel to a side of triangle intersecting the other two sides, divides the sides in the same ratio.

Proof
Given : In ∆ABC, D is a point on AB and E is a point on AC.
To prove : $\frac{A D}{D B}=\frac{A E}{E C}$
Construction : Draw a line DE || BC

Question 37.
Find the value of k, if the area of a quadrilateral is 28 sq. units, whose vertices are (-4, -2), (-3, k), (3,-2) and (2,3)
Answer:
Let the vertices A (-4, -2), B (-3, k), C (3, -2) and D (2, 3)
Area of the Quadrilateral = 28 sq. units
$\frac { 1 }{ 2 }$ [(x₁y₂ + x₂y₃ + x₃y₄ + x₄y₁) – (x₂y₁ + x₃y₂ + x₄y₃ + x₁y₄)] = 28

$\frac { 1 }{ 2 }$ [(-4k + 6 + 9 – 4)-(6 + 3k – 4 – 12)] = 28
$\frac { 1 }{ 2 }$ [(-4k + 11) – (3k – 10)] = 28
-4k + 11 – 3k + 10 = 56
-7k + 21 = 56
-7k = 56 – 21
-7k = 35 ⇒ 7k = -35
k = $-\frac{35}{7}$ = -5
∴ The value of k = -5

Question 38.
A bird is sitting on the top of a 80 m high tree. From a point on the ground, the angle of elevation of the bird is 45° . The bird flies away horizontally in such away that it remained at a constant height from the ground. After 2 seconds, the angle of elevation of the bird from the same point is 30° . Determine the speed at which the bird flies. (√3 = 1.732)
Answer:
A is the initial position of the bird
B is the final position of the bird
Let the speed of the bird be “s”
Distance = speed × time

∴ AB = 2 s
Let CD be x
∴ CE = x + 2s
In the ∆ CDA, tan 45° = $\frac{A D}{C D}$
1 = $\frac{80}{x}$
x = 80 …(1)
In the ∆ BCE
tan 30° = $\frac{\mathrm{BE}}{\mathrm{CE}}$
$\frac{1}{\sqrt{3}}=\frac{80}{x+2 s}$
x + 2 s = 80 √3
x = 80 √3 – 2 s …(2)
From (1) and (2) we get
80 √3 – 2 s = 80
80 √3 – 80 = 2s ⇒ 80(√3 – 1) = 2 s
s = $\frac{80(\sqrt{3}-1)}{2}$ = 40 (1.732 – 1) = 40 × 0. 732 = 29. 28
Speed of the flying bird = 29. 28 m / sec

Question 39.
The total marks scored by two students Sathya and Vidhya in 5 subjects are 460 and 480 with standard deviation 4.6 and 2.4 respectively. Who is more consistent in performance?
Answer:
Total marks scored by Sathya = 460
Total marks scored by Vidhya = 480
Number of subjects = 5
x̄ = 92%
Mean marks of Sathya = $\frac{460}{5}$
Given standard deviation, (σ) = 4.6
Coefficient of variation = $\frac{\sigma}{\bar{x}} \times 100 \%$
= $\frac{4.6}{92} \times 100 \%$
= $\frac{460}{92}=5 \%$
Mean marks of vidhya = $\frac{480}{5}$
Given standard deviation (σ) = 2.4
Coefficient of variation = $\frac{2.4}{96} \times 100=\frac{240}{96}=2.5 \%$
CV₁ > CV₂
Vidhya coefficient of variation is less than Sathya
∴ Vidhya is more consistent.

Question 40.
The perimeters of the ends of frustum of a cone are 207.24 cm and 169.56 cm. If the height of the frustum be 8 cm, find the whole surface area of the frustum. [Use π = 3.14]
Answer:

Let the radii of circular ends be R and r [R > r]
Perimeter of circular ends are 207.24 cm and 169.56 cm
∴ 2πR = 207.24 cm
⇒ R = $\frac{207.24}{2 \pi}=\frac{207.24}{2 \times 3.14}=33$
⇒ R = 33m and 2 πr = 169.56
⇒ r = $\frac{169.56}{2 \pi}=\frac{169.56}{2 \times 3.14}=27$
Slant-height of the frustum
l = $\sqrt{h^{2}+(\mathrm{R}-r)^{2}}$
$=\sqrt{8^{2}+(33-27)^{2}}$
$=\sqrt{64+36}$ = 10 cm
The whole surface area of the frustum = π [(R² + r2²) + (R + r) l]
∴ Required whole surface area of the frustum
= 3.14 [33² + 27² + (33 + 27) × 10] cm²
= 3.14 [1089 + 729 + 600] cm²
= 3.14 [2418] cm²
= 7592.52 cm²

Question 41.
A jar contains 54 marbles each of which is blue, green or white. The probability of selecting a blue marbles at random from the jar is $\frac { 1 }{ 3 }$ and the probability of selecting a green marble at random is $\frac { 4 }{ 9 }$ . How many white marbles does the jar contain?
Answer:
n(S) =54
Let the number of blue marble, be ‘x’
Let A be the event of getting blue marbles
n(A) = x
P(A) = $\frac{n(\mathrm{A})}{n(\mathrm{S})}$
$\frac{1}{3}=\frac{x}{54}$
3x = 54
x = $\frac{54}{3}$ = 18
Number of blue marble is 18. Let the number of green marble be “y”. Let B be the event of getting green marbles.

P(B) = $\frac{n(\mathrm{B})}{n(\mathrm{S})}$
$\frac{4}{9}=\frac{y}{54}$
9y = 54 × 4
y = $\frac{54 \times 4}{9}$ = 24
Blue marbles + green marbles + white marbles = 54
18 + 24 + white marbles = 54
∴ Number of white marbles = 54 – 42 = 12
The jar contain 12 white marbles.

Question 42.
One – fourth of a herd of camels was seen in the forest. Twice the square root of the herd had gone to mountain and the remaining 15 camels were seen on the bank of a river. Find the total number of camels.
Answer:
Le the total number of camels be ‘x’
Number of camels seen in the forest = $\frac { x }{ 4 }$
Number of camels gone to the mountain = 2√x
Number of camels on the bank of river = 15
Total number of camels = $\frac { x }{ 4 }$ + 2√x + 15
x = $\frac { x }{ 4 }$ + 2√x + 15
4x = x + 8√x + 60 (muliply by 4)
3x – 8√x – 60 = 0
Let x = a²
3a² – 8√a² – 60 = 0
3a² – 8a – 6 = 0
3a (a – 6) + 10(a – 6) = 0
(3a + 10) (a – 6) = 0
3a + 10 = 0 or a – 6 = 0
a = $\frac{-10}{3}$ or a = 6
x = $\left(\frac{-10}{3}\right)^{2}$ or 6²(x = a²)
x = $\frac{100}{9}$ (or) 36
Number of camels can-not be a fraction
∴ Number of camels = 36

PART – IV

IV. Answer all the questions. [2 × 8 = 16]

Question 43.
(a) Construct a triangle similar to a given triangle PQR with its sides equal to $\frac { 7 }{ 4 }$ of the corresponding sides of the triangle PQR
Answer:
Given a triangle PQR, we are required to construct another triangle whose sides are $\frac { 7 }{ 4 }$ of the corresponding sides of the triangle PQR.

Steps of construction
1. Construct a ∆PQR with any measurement.
2. Draw a ray QX making an acute angle with QR on the side opposite to vertex P.
3. Locate 7 points (the greater of 7 and 4 in $\frac { 7 }{ 4 }$)
Q₁, Q₂, Q₃, Q₄, Q₅, Q₆ and Q₇ on QX so that
QQ₁ = Q₁Q₂ = Q₂Q₃ = Q₃Q₄= Q₄Q₅ = Q₅Q₆ = Q₆Q₇
4. Join Q₄ (the 4^th point, 4 being smaller of 4 and 7 in $\frac { 7 }{ 4 }$) to R and draw a line through Q₇ parallel to Q₄ R, intersecting the extended line segment QR at R’.
5. Draw a line through R’ parallel to RP intersecting the extended line segment QP at P’ Then ∆P’QR’ is the required triangle each of whose sides is seven-fourths of the corresponding sides of ∆PQR.

[OR]

(b) Take a point which is 11 cm away from the centre of a circle of radius 4 cm and draw the two tangents to the circle from that point.
Answer:
Radius = 4 cm; Distance 11 cm

Steps of construction:

With O as centre, draw a circle of radius 4 cm.
Draw a line OP = 11 cm.
Draw a perpendicular bisector of OP, which cuts OP at M.
With M as centre and MO as radius, draw a circle which cuts previous circle A and B.
Join AP and BP. AP and BP are the required tangents.
This the length of the tangents PA = PB = 10.2 cm

Verification: In the right angle triangle OAP
PA² = OP² – OA²
= 11² – 4² = 121 – 16= 105
PA = √105 = 10.2 cm
Length of the tangents = 10.2 cm

Question 44.
(a) Draw the graph of y = x² + 3x + 2 and use it to solve x² + 2x + 1 = 0.
Answer:
(i) Draw the graph of y = x² + 3x + 2 preparing the table of values as below.

(ii) Plot the points (-4, 6), (-3, 2), (-2, 0), (-1, 0), (0, 2), (1, 6), (2, 12), (3, 20) (4, 30).
(iii) To solve x² + 2x + 1 = 0 subtract x² + 2x + 1 = 0 from y = x² + 3x + 2

(iv) Draw the graph of y = x +1 from the table

The equation y = x + 1 represents straight line.
This line intersect the curve at only one point (-1, 0). The solution set is (-1).

[OR]

(b) (2x – 3) (x + 2) = 0
y = (2x – 3) (x + 2)
= 2x² + 4x – 3x – 6
= 2x² + x – 6
(i) Prepare a table of values for y from x – 4 to 4

(ii) Plot the points (-4, 22) (-3, 9) (-2, 0) (-1, -5) (0, -6) (1,-3), (2, 4), (3, 15) and (4, 30).
(iii) Join the points by a free hand smooth curve.
The curve intersect the X – axis at (-2, 0) and $\left(1 \frac{1}{2}, 0\right)$
∴ The solution set is $\left(-2,1 \frac{1}{2}\right)$
(iv) Since there are two points of intersection with X – axis, the quadratic equation has real and un – equal roots.

Samacheer Kalvi 10th Science Model Question Paper 2 English Medium

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Tamil Nadu Samacheer Kalvi 10th Science Model Question Paper 2 English Medium

General Instructions:

The question paper comprises of four parts
You are to attempt all the questions in each part. An internal choice of questions is provided wherever applicable.
All questions of Part I, II, III and IV are to be attempted separately.
Question numbers 1 to 12 in Part I are Multiple Choice Questions of one mark each.
These are to be answered by writing the correct answer along with the corresponding option code.
Question numbers 13 to 22 in Part II are of two marks each. Any one question should be answered compulsorily.
Question numbers 23 to 32 in Part III are of four marks each. Any one question should be answered compulsorily.
Question numbers 33 to 35 in Part IV are of seven marks each. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 75

Part – I

(i) Answer all the questions. [12 × 1 = 12]
(ii) Choose the most suitable answer and write the code with the corresponding answer.

Question 1.
Inertia of a body depends on ______.
(a) weight of the object
(b) acceleration due to gravity of the planet
(c) mass of the object
(d) Both a & b
Answer:
(c) mass of the object

Question 2.
Magnification of a convex lens is _______.
(a) Positive
(b) Negative
(c) either positive or negative
(d) zero
Answer:
(b) Negative

Question 3.
When a sound wave travels through air, the air particles _______.
(a) vibrate along the direction of the wave motion
(b) vibrate but not in any fixed direction
(c) vibrate perpendicular to the direction of the wave motion
(d) do not vibrate
Answer:
(a) vibrate along the direction of the wave motion

Question 4.
The number of neutrons is ₈O¹⁶ is _______.
(a) 8
(b) 16
(c) 32
(d) 24
Answer:
(a) 8

Question 5.
Which of the following is a triatomic molecule?
(a) Glucose
(b) Helium
(c) Carbon-di-oxide
(d) Hydrogen
Answer:
(c) Carbon-di-oxide

Question 6.
Photolysis is a decomposition reaction caused by ______.
(a) heat
(b) electricity
(c) light
(d) mechanical energy
Answer:
(c) light

Question 7.
Water which is absorbed by roots is transported to aerial parts of the plant through ________.
(a) phloem
(b) epidermis
(c) cortex
(d) xylem
Answer:
(d) xylem

Question 8.
World ‘No Tobacco Day’ is observed on _______.
(a) May 31^st
(b) April 22^nd
(c) June 6^th
(d) October 2^nd
Answer:
(a) May 31^st

Question 9.
Oxygen is produced at what point during photosynthesis?
(a) when ATP is converted to ADP
(b) when CO₂ is fixed
(c) when H₂O is splitted
(d) All of these
Answer:
(b) when CO₂ is fixed

Question 10.
The phenomenon by which carbohydrates are oxidised to release ethyl alcohol is
(a) Glycolysis
(b) Kreb’s cycle
(c) Photosynthesis
(d) Fermentation
Answer:
(d) Fermentation

Question 11.
Biogenetic law states that ______.
(a) Ontogeny and phylogeny go together
(b) Ontogeny recapitulates phylogeny
(c) Phylogeny recapitulates ontogeny
(d) There is no relationship between phylogeny and ontogeny
Answer:
(b) Ontogeny recapitulates phylogeny

Question 12.
Where you will create category of blocks?
(a) Block palette
(b) Block menu
(c) Script area
(d) Sprite
Answer:
(b) Block menu

Part – II

Answer any seven questions. (Q.No: 22 is compulsory) [7 × 2 = 14]

Question 13.
State Boyle’s law.
Answer:
When the temperature of a gas is kept constant, the volume of a fixed mass of gas is inversely proportional to its pressure. P ∝ $\frac{1}{V}$

Question 14.
Differentiate mass and weight.
Answer:

Mass	Weight
1. The quantity of matter contained in the body	1. The gravitation force exerted on it due to the Earth’s gravity alone.
2. Scalar quantity	2. Vector quantity
3. Unit: kg	3. Unit: N
4. Constant at all the places	4. Variable with respect to gravity.

Question 15.
Why are traffic signals red in colour?
Answer:

Red light has the highest wavelength.
It is scattered by atmospheric particles.
So red light is able to travel the longest distance through fog, rain etc.

Question 16.
Define volume percentage.
Answer:
Volume percentage is defined as the percentage by volume of solute (in ml) present in the given volume of the solution.

Question 17.
Give any two examples for heterodiatomic molecules.
Answer:
Heterodiatomic molecules -E.g: HCl, NaCl.

Question 18.
Match the following:

Answer:
(a) (ii)
(b) (iv)
(c) (iii)
(d) (i)

Question 19.
Write the differences between endocrine and exocrine gland.
Answer:

Endocrine	Exocrine
1. Secretion of endocrines are hormones	1. Secretion of exocrines are enzymes
2. Endocrine glands do not have specific duct hence ductless gland.	2. Exocrine glands have specific duct to carry their secretions.
3. Eg. Pituitary gland	3. Eg. Salivary gland

Question 20.
Identify the parts A,B,C and D.
Answer:

A – Exine, B – Intine, C – Generative cell, D – Vegetative nucleus

Question 21.
Define Cancer.
Answer:
Cancer is an abnormal and uncontrolled division of cells that invade and destroy surrounding tissue forming a tumor or neoplasm: It is a heterogenous group of cells that do not respond to the normal cell division.

Question 22.
The potential difference between two conductor is 110 V. How much work moving 5C charge from one conductor to the other?
Answer:
Given, V = 110 V , Charge q = 5C
V = $\frac{W}{q}$
W = V × q
W = 110 × 5 = 550 J
∴ Work done W = 550 J

Part – III

Answer any seven questions (Q.No: 32 is compulsory) [7 × 4 = 28]

Question 23.
Describe the rocket propulsion.
Answer:

Propulsion of rockets is based on the law of conservation of linear momentum as well as Newton’s III law of motion.
Rockets are filled with a fuel (either liquid or solid) in the propellant tank. When the rocket is fired, this fuel is burnt and a hot gas is ejected with a high speed from the nozzle of the rocket, producing a huge momentum.
To balance this momentum, an equal and opposite reaction force is produced in the combustion chamber, which makes the rocket project forward.
While in motion, the mass of the rocket gradually decreases, until the fuel is completely burnt out.
Since, there is no net external force acting on it, the linear momentum of the system is conserved.
The mass of the rocket decreases with altitude, which results in the gradual increase in velocity of the rocket.
At one stage, it reaches a velocity, which is sufficient to just escape from the gravitational pull of the Earth. This velocity is called escape velocity.

Question 24.
Explain the types of Scattering.
Answer:
Types of Scattering.
When a beam of light, interacts with a constituent particle of the medium, it undergoes many kinds of scattering.
Based on initial and final energy of the light beam, scattering can be classified as,

Elastic scattering
Inelastic scattering

1. Elastic scattering:
If the energy of the incident beam of light and the scattered beam of light are same, then it is called as ‘elastic scattering’.

2. Inelastic scattering:
If the energy of the incident beam of light and the scattered beam of light are not same, then it is called as ‘inelastic scattering’.
The nature and size of the scattered results in different types of scattering. They are

Raylight scattering
Mie scattering
Tyndall scattering
Raman scattering

Question 25.
(a) Calculate the current and the resistance of a 100 W, 200 V electric bulb in an electric circuit.
Answer:
Given, P = 100 W, V = 200 V
Power P = VI

(b) What is the role of the earth wire in domestic circuits?
Answer:

The earth wire provides a low resistance path to the electric current.
The earth wire sends the current from the body of the appliance to the Earth, whenever a live wire accidentally touches the body of the metallic electric appliance.
Thus, the earth wire serves as a protective conductor, which saves us from electric shocks.

Question 26.
Explain the mechanism of cleansing action of soap.
Answer:
A soap molecule contains two chemically distinct parts that interact differently with water. It has one polar end, which is a short head with a carboxylate group (-COONa) and one nonpolar end having the long tail made of the hydrocarbon chain.

The polar end is hydrophilic (Water loving) in nature and this end is attracted towards water. The non-polar end is hydrophobic (Water hating) in nature and it is attracted towards dirt or oil on the cloth, but not attracted towards water. Thus, the hydrophobic part of the soap molecule traps the dirt and the hydrophilic part makes the entire molecule soluble in water.

When a soap or detergent is dissolved in water, the molecules join together as clusters called ‘micelles’. Their long hydrocarbon chains attach themselves to the oil and dirt. The dirt is thus surrounded by the non-polar end of the soap molecules. The charged carboxylate end of the soap molecules makes the micelles soluble in water. Thus, the dirt is washed away with the soap.

Question 27.
(a) Explain the various types of binary solutions based on the physical states of solute and solvent table.
Answer:

(b) State Henry’s law?
Answer:
Henry’s law states that, the solubility of a gas in a liquid, is directly proportional to the pressure of the gas over the solution at a definite temperature.

Question 28.
(a) Give an example for conditioned reflexes.
Answer:
Playing harmonium by striking a particular key, on seeing a music note is an example of conditioned reflexes which required conscious training effort.

(b) How many cranial nerves and spinal nerves are present in man?
Answer:
12 pairs of cranial nerves and 31 pairs of spinal nerves are present in man.

Question 29.
(a) What are Allosomes?
Answer:
Allosomes are chromosomes which are responsible for determining the sex of an individual. There are two types of sex chromosomes. X and Y chromosomes. Human male have one X chromosome and one Y chromosomes and the human female have two X chromosomes.

(b) What causes the opening and closing of guard cells of stomata during transpiration?
Answer:
The opening and closing of stomata is due to the change in turgidity of the guard cells. When the water enters into the guard cells, they become turgid and the stomata open. When guard cells lose water, it becomes flaccid and the stomata closes.

Question 30.
(a) Draw and label the structure of oxysomes
Answer:

(b) What is respiratory quotient?
Answer:
The ratio of volume of carbon dioxide liberated and the volume of oxygen consumed, during respiration is called Respiratory Quotient (R.Q)

Question 31.
(a) Why is a dietary restriction recommended for an obese individual?
Answer:
Obesity is a positive risk factor in development of hypertension, diabetes, gall bladder disease, coronary heart disease and arthritis. Hence dietary restriction is recommended for an obese individual.

(b) Give the name of wheat variety having higher dietary fibre and protein.
Answer:
Triticale (6n) is a hybrid of wheat and rye. It has higher dietary fibre and protein.

Question 32.
(a) State Newton’s third law of motion and explain with examples:
Answer:
Law: ‘For every action, there is an equal and opposite reaction.
They always act on two different bodies’.
F_B = – F_A

Examples:
(i) When birds fly:
Push the air downwards with their wings – Action
Air push the bird upwards – Reaction

(ii) When firing bullet:
Gun recoils backward and the bullet is moving forward – Action
Gun equals this forward action by moving backward – Reaction.

(b) How will you identify saturated and unsaturated compounds?
Answer:

Take the given sample solution in a test tube.
Add a few drops of bromine water
If the given compound is unsaturated, it will decolourise bromine water.
If the given compound is saturated it will not decolourise bromine water.

Part – IV

(1) Answer all the questions. [3 × 7 = 21]
(2) Each question carries seven marks.
(3) Draw diagram wherever necessary.

Question 33.
(a) (i) State Rayleigh’s law of scattering.
Answer:
Rayleigh’s scattering law states that “The amount of scattering of light is inversely proportional to the fourth power of its wavelength”.
Amount of scattering, S ∝ $\frac{1}{\lambda^{4}}$

(ii) Explain the construction and working of a ‘compound microscope’.
Answer:
Construction
A compound microscope consists of two convex lenses. The lens with the shorter focal length is placed near the object, and is called as ‘objective lens’ or ‘objective piece’. The lens with larger focal length and larger aperture placed near the observer’s eye is called as ‘eye lens’ or ‘eye piece’. Both the lenses are fixed in a narrow tube with adjustable provision.

Working:
(i) The object (AB) is placed at a distance slightly greater than the focal length of objective lens (u >fo).
(ii) A real, inverted and magnified image (A’B’) is formed at the other side of the objective lens.
(iii) This image behaves as the object for the eye lens. The position of the eye lens is adjusted in such a way, that the image (A’B’) falls within the principal focus of the eye piece.
(iv) This eye piece forms a virtual, enlarged and erect image (A” B”) on the same side of the object.
(v) Compound microscope has 50 to 200 times more magnification power than simple microscope.

[OR]

(b) (i) A heavy truck and bike are moving with the same kinetic energy. If the mass of the truck is four times that of the bike, then calculate the ratio of their momenta. (Ratio of momenta = 1:2)
Answer:
Given: Let m_b , m_t are the masses of truck and bike.
mt = 4m_b ………(1)

(ii) Air temperature in the Rajasthan desert can reach 46°C. What is the velocity of sound in air at that temperature? (v₀ = 331 ms^-1)
Answer:
V_T = (V₀ + 0.16 T)
T = 46°C, v₀ =331 ms^-1
_VT = 331 +(0.61 × 46)
= 331 +28.06
V_T = 359.06 ms^-1

Question 34.
(a) (i) A solution is prepared by dissolving 15 g of NaCl in 85 g of water. Calculate the mass percentage of solute.
Answer:
Mass of solute = 15 g
Mass of solvent = 85 g

(ii) Calculate the pH of 0.001 M NaOH.
Answer:
[OH^–] = Normality = Molarity × acidity
= 0.001 × 1 = 1 × 10^-3
pOH = -log₁₀[OH^–]
= -log₁₀¹× [10^-3]
= -log ¹– log₁₀ 10^-3
= 0 – (-3 log₁₀ ¹⁰)
pOH = 3
pH + pOH = 14 .
pH = 14 – pOH= 14 – 3
pH = 11

(iii) Calculate the mass of 0.01 mole of H₂O.
Answer:
n = 0.01 mole; μ = 18 g mol^-1; W = ?
W = n × M
= 0.01 × 18 = 0.18 g

[OR]

(b) (i) In what way hygroscopic substances differ from deliquescent substances.
Answer:
Difference between hygroscopic and deliquescent substances is in the extent to which each material can absorb moisture. This is because both of these terms are very much related to each other and they refer to the property of observing and the retention of moisture from the air. However, they differ in the extent of absorption of moisture where hygroscopic materials absorb moisture but not the extent the original substance dissolves in it, which is the casewith deliquescence. Therefore deliquescence can be regarded as an extreme condition of hygroscopic activity.

Hygroscopic substances	Deliquescence substance
1. When exposed to the atmosphere at ordinary temperature, they absorb moisture and do not dissolve.	1. When exposed to the atmospheric air at ordinary temperature, they absorb moisture and dissolve.
2. Hygroscopic substances do not change its physical state on exposure to air.	2. Deliquescent substances change its physical state on exposure to air.
3. Hygroscopic substances may be amorphous solids or liquids.	3. Deliquescent substances are crystalline solids.

(ii) Define solubility.
Answer:
It is defined as the number of grams of a solute that can be dissolved in 100 g of a solvent to form its saturated solution at a given temperature and pressure.

Question 35.
(a) (i) Which hormone is known as stress hormone in plants ? Why?
Answer:
Abscisic acid (ABA) is a growth, inhibitor which regulates abscission and dormancy. It increases tolerance of plants to various kinds of stress. So, it is also called as stress hormone. It is found in the chloroplast of plants.

(ii) How does binary fission differ from multiple fission?
Answer:

Binary fission	Multiple fission
1. Binary fission is the splitting of a cell into two daughter cell	1. Multiple fission is splitting of a parent cell into two or more daughter cells.
2. It takes place in favourable conditions. Eg. Amoeba	2. It takes place in unfavourable conditions. Eg. Plasmodium

(iii) What are the sources of solid wastes? How are solid wastes managed?
Answer:
Solid wastes mainly include municipal wastes, hospital wastes, industrial wastes and e-wastes, etc.

Methods of solid wastes disposal:
(1) Segregation: It is the separation of different type of waste materials like biodegradable and non-biodegradable wastes.

(2) Sanitary landfill: Solid wastes are dumped into low lying areas. The layers are compacted by trucks to allow settlement. The waste materials get stabilised in about 2-12 months. The organic matter undergoes decomposition.

(3) Incineration: It is the burning of non-biodegradable solid wastes (medical wastes) in properly constructed furnace at high temperature.

(4) Composting: Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.

[OR]

(b) (i) Explain the male reproductive system of rabbit?
Answer:

The male reproductive system of rabbit consists of a pair of testes which are ovoid in shape. Testes are enclosed by scrotal sacs in the abdominal cavity. Each testis consists of numerous fine tubules called seminiferous tubules.
This network of tubules lead into Cowper s glands a coiled tubule called epididymis, Perineal glands which lead into the sperm duct called vas deferens.

The vas deferens join in the urethra just below the urinary bladder. The urethra runs backward and passes into the penis. There are three accessory glands namely prostate gland, cowper’s gland and perineal gland. Their secretions are involved in reproduction.

(ii) What are vestigeal organs?
Answer:
The degenerated and non functional organs of animals are called Vestigeal organs. Eg. Vermiform appendix, nictitating membrane, caudal vertebra, coccyx.

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