Are these practice questions for Kinetic Theory based on the CBSE pattern?

Yes. Every practice question is modeled on the CBSE Class 11 - Science Physics exam pattern — including MCQs, assertion-reason questions, and short-answer formats that frequently appear in CBSE papers.

Are the practice questions for Kinetic Theory free?

Yes. Every chapter includes free practice questions for Class 11 - Science students to get you started.

What types of questions are included?

The practice set for Kinetic Theory mainly includes MCQs and CBSE-style short-answer questions, with instant feedback on each answer. For full-length textbook practice, use the NCERT Solutions page.

Are the practice questions suitable for board exam preparation?

Yes. The questions test the same concepts and depth that CBSE asks in board exams. After finishing, also solve the NCERT and NCERT Exemplar exercises for Kinetic Theory for full coverage.

How many practice questions are there for Kinetic Theory?

The number scales with chapter length and concept density. Each chapter typically has 15-50 practice questions across MCQ and short-answer formats.

Kinetic Theory Class 11 Physics Practice Questions with Answers

easy

State Avogadro's law regarding the volume and number of molecules of gases.

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easy

Apply the law of equipartition of energy to determine the average energy associated with a single translational degree of freedom of a gas molecule at temperature T.

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easy

Define the term 'mean free path' as used in the kinetic theory of gases.

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easy

Calculate the pressure exerted by

2

moles of an ideal gas kept in a container of volume

0.05 \text{ m}^3

at a temperature of

300 \text{ K}

. Use the ideal gas equation and assume

R = 8.314 \text{ J mol}^{-1} \text{K}^{-1}

.

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easy

Name the physical quantity that is a measure of the average translational kinetic energy of the molecules of a gas.

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easy

Justify why the average kinetic energy of gas molecules is considered a measure of temperature, but the average momentum is not.

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easy

Analyze what happens to the average translational kinetic energy of molecules in an ideal gas if its absolute temperature is quadrupled.

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easy

Recall the ideal gas equation in terms of the number of moles (

\mu

) and the universal gas constant (

R

).

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easy

Justify the statement: 'At the same temperature, a molecule of hydrogen gas has a higher root mean square speed than a molecule of oxygen gas.' Use the kinetic interpretation of temperature to support your argument.

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easy

State the relationship between the universal gas constant (

R

), Avogadro's number (

N_A

), and Boltzmann's constant (

k_B

).

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easy

Recall the expression for the pressure exerted by an ideal gas,

P = \frac{1}{3} n m \overline{v^2}

. Identify what each symbol (

n, m, \overline{v^2}

) represents.

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medium

Explain Dalton's law of partial pressures using the kinetic theory of gases.

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medium

Describe how the pressure of a gas is explained by the kinetic theory.

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medium

Analyze how the mean free path of gas molecules in a container changes if the gas is compressed to half its original volume while keeping the temperature constant.

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medium

A cylinder with a fixed volume contains

3

moles of a monatomic ideal gas at an initial temperature of

27^{\circ}\text{C}

. Calculate the amount of heat required to raise the temperature of the gas to

127^{\circ}\text{C}

. Also, calculate the change in its internal energy. (Given

R = 8.31 \text{ J mol}^{-1} \text{K}^{-1}

)

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medium

Evaluate the assumption in the kinetic theory that molecular collisions are perfectly elastic. Why is this assumption crucial for the derivation of the ideal gas pressure equation,

P = \frac{1}{3} n m \overline{v^2}

?

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medium

Calculate the root mean square speed of an oxygen molecule (

O_2

) at a temperature of

27^{\circ}\text{C}

. The molecular mass of oxygen is

32.0 \text{ g/mol}

, and

R = 8.314 \text{ J mol}^{-1} \text{K}^{-1}

.

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medium

Explain the kinetic interpretation of temperature based on the kinetic theory of gases.

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medium

Contrast the behavior of a real gas with that of an ideal gas, particularly under conditions of high pressure and low temperature. Explain the reasons for the deviations based on the assumptions of the kinetic theory.

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medium

A container holds a mixture of helium (He) and nitrogen (

N_2

) gas at the same temperature. Compare the root mean square (

v_{rms}

) speeds of the molecules of the two gases. The atomic mass of He is

4.0 \text{ u}

and the molecular mass of

N_2

is

28.0 \text{ u}

.

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medium

Justify why, for a polyatomic molecule with

f

vibrational modes, the molar specific heat at constant volume is given by

C_V = (3+f)R

, assuming 3 translational and 3 rotational degrees of freedom.

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medium

List the four main assumptions of the kinetic theory of an ideal gas.

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medium

Propose a reason why the law of equipartition of energy fails to explain the specific heats of gases at very low temperatures.

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medium

Identify the factors on which the mean free path of a gas molecule depends and describe the relationship.

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medium

Create a scenario where two different ideal gases, Helium (He) and Argon (Ar), are mixed in a container. If the ratio of their masses is

1:10

and the temperature is constant at

300 \text{ K}

, formulate an expression for the ratio of their root mean square speeds,

(v_{rms})_{He} / (v_{rms})_{Ar}

.

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medium

A cube of side

10 \text{ cm}

contains helium gas. The number of molecules per unit volume is

2 \times 10^{25} \text{ m}^{-3}

and the mass of a helium atom is

6.64 \times 10^{-27} \text{ kg}

. If the root mean square speed of the atoms is

1360 \text{ m/s}

, solve for the pressure inside the cube.

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medium

Examine the relationship

PV = \frac{2}{3} E

, where

E

is the total translational kinetic energy of an ideal gas. How does this equation connect the macroscopic properties (

P, V

) of a gas to its microscopic property (

E

)?

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medium

What is the value of the molar specific heat at constant volume (

C_V

) for a monatomic ideal gas in terms of the universal gas constant

R

?

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medium

An ideal gas has its temperature changed from

27^{\circ}\text{C}

to

327^{\circ}\text{C}

. Recall the formula for the root mean square speed and find the ratio of its initial rms speed to its final rms speed.

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medium

Critique the ideal gas model. Under what conditions does it fail to accurately predict the behavior of a real gas? Propose two main reasons for its failure, relating them to the postulates of the kinetic theory.

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medium

Formulate a model to explain why the specific heat capacity of a diatomic gas increases at very high temperatures. Your model should critique the 'rigid rotator' assumption and incorporate vibrational degrees of freedom.

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medium

Propose a method to increase the mean free path of gas molecules within a sealed container without changing the type of gas or the container's volume. Justify your proposal using the formula for mean free path,

l = \frac{1}{\sqrt{2} n \pi d^2}

.

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medium

Compare the value of the ratio of specific heats (

\gamma = C_p/C_v

) for a monatomic gas and a rigid diatomic gas. Analyze the reason for the difference based on their degrees of freedom.

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hard

Explain the concept of degrees of freedom and list the number of translational and rotational degrees of freedom for monatomic, diatomic (rigid), and non-linear polyatomic gases.

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hard

Calculate the mean free path for a nitrogen molecule (

N_2

) in a sample of gas at standard temperature and pressure (STP). At STP, the number density of molecules is approximately

2.7 \times 10^{25} \text{ m}^{-3}

. Take the diameter of a nitrogen molecule to be

3.15 \times 10^{-10} \text{ m}

.

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hard

Critique the assumption that molecules in an ideal gas only collide with the walls and not with each other. Explain why, despite this simplification, the final expression

P=(1/3)nm\overline{v^2}

remains valid for a gas in a steady state.

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hard

A vessel is divided into two equal compartments by a partition. One compartment contains Helium (monatomic) and the other contains Oxygen (diatomic), both at the same initial temperature

T

and pressure

P

. Formulate a prediction for what happens to the total pressure and the temperature of the mixture if the partition is removed. Justify your prediction.

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hard

Design a hypothetical experiment to verify the law of equipartition of energy for a diatomic gas like Nitrogen (

N_2

) at moderate temperatures. Your design should specify the measurements needed and how you would calculate the molar specific heats (

C_V

and

C_p

) to justify that it has 5 degrees of freedom.

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hard

A vessel of volume

V

contains a mixture of two non-reactive gases, Hydrogen (

H_2

) and Oxygen (

O_2

), at temperature

T

. The partial pressure of Hydrogen is twice that of Oxygen. The molecular mass of

H_2

is

2.0 \text{ u}

and that of

O_2

is

32.0 \text{ u}

. Calculate the ratio of (i) the number of molecules of

H_2

to

O_2

and (ii) the mass density of

H_2

to

O_2

in the mixture.

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hard

Design an experiment to estimate the diameter of an argon atom using the concept of mean free path. You are given a container of argon gas at a known pressure

P

and temperature

T

, and you can measure the gas's viscosity, which is related to the mean free path. Outline the steps and the formulas you would use to arrive at the diameter

d

.

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hard

Calculate the temperature at which the root mean square speed of an argon atom (Ar) is equal to the rms speed of a neon atom (Ne) at

-73^{\circ}\text{C}

. The atomic mass of Ar is

39.9 \text{ u}

and that of Ne is

20.2 \text{ u}

.

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hard

A scientist claims to have created a gas where all molecules move at the exact same speed. Evaluate this claim in the context of the kinetic theory of gases. Would the concepts of 'temperature' and 'pressure' as derived from kinetic theory still be valid for this hypothetical gas? Justify your reasoning.

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hard

Summarize the law of equipartition of energy and explain how it applies to translational, rotational, and vibrational degrees of freedom for a molecule.

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hard

Evaluate the claim that the total pressure of a mixture of non-reacting gases is the sum of their partial pressures (Dalton's Law). Justify this law starting from the kinetic theory pressure equation

P = \frac{1}{3} n m \overline{v^2}

and the kinetic interpretation of temperature.

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hard

Demonstrate that for a mixture of non-reacting ideal gases, the total pressure is the sum of the partial pressures exerted by each gas (Dalton's Law), using the kinetic theory of gases.

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Kinetic TheoryClass 11 Physics Practice Questions