An ideal gas equation can be written as, P = ρ R T M 0 where ρ and M 0 are respectively,

number density, mass of the gas

EASY

Earn 100

Assertion: The potential energy of ideal gas is zero.

Reason: At low pressure or high temperature the molecules are far apart and molecular interactions are negligible.

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Important Questions on Kinetic Theory of Gases

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Number of molecules in a volume of

4 {cm}^{3}

of a perfect monoatomic gas at some temperature

T

and at a pressure of

2 cm

of mercury is close to? (Given, mean kinetic energy of a molecule (at T) is

4 \times 10^{- 14} erg, g = 980 cm s^{- 2}

density of mercury

= 13.6 g {cm}^{- 3}

)

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Two vessels separately contain two ideal gases

A

and

B

at the same temperature, the pressure of

A

being twice that of

B

. Under such conditions, the density of

A

is found to be

1.5

times the density of

B

. The ratio of molecular weights of

A

and

B

HARD

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Particle

A

of mass

m_{A} = \frac{m}{2}

moving along the

x

-axis with velocity

v_{0}

collides elastically with another particle

B

at rest having mass

m_{B} = \frac{m}{3}

. If both the particles move along the

x

-axis after the collision, the change

∆ λ

in the wavelength of the particle

A

, in terms of its de-Broglie wavelength

(λ_{0})

before the collision is:

MEDIUM

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

A spring - block system is resting on a frictionless floor as shown in the figure. The spring constant is

2.0 N m^{- 1}

and the mass of the block is

2 .0 kg

. Ignore the mass of the spring. Initially the spring is in an unstretched condition. Another block of mass

1.0 kg

moving with a speed of

2 .0 m s^{- 1}

collides elastically with the first block. The collision is such that the

2.0 kg

block does not hit the wall. The distance, in metres, between the two blocks when the spring returns to its unstretched position for the first time after the collision is _________.

Question Image

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

The molecules of a given mass of gas have RMS velocity of

200

m s^{- 1}

27^{o} C

and

1.0 \times 10^{5} N m^{- 2}

pressure. When the temperature and pressure of the gas are respectively,

127^{o} C

and

0.05 \times 10^{5} N m^{- 2}

, the r.m.s. velocity of its molecules in

m s^{- 1}

is:

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

According to the assumptions made in the kinetic theory of gases, when two molecules of a gas collide with each other then

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

If pressure and temperature of an ideal gas are doubled and volume is halved, the number of molecules of gas

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

If the water is converted into ice, and its entropy is changed by

Δ S,

then

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Increase in temperature of a gas filled in a container will lead to

MEDIUM

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

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

volume cylinder is filled with

1

mol of

O_{2}

gas at room temperature

(300 K)

. The molecular diameter of

O_{2}

, and its root mean square speed, are found to be

0.3 n m

and

200 m s^{- 1}

, respectively. What is the average collision rate (per second) for an

O_{2}

molecule?

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Some smoke is trapped in a small glass container and is viewed through a microscope. A number of very small smoke particles are seen in continuous random motion as a result of their bombardment by air molecules. If the mass of the smoke particle is about $10^{12}$ times higher than that of an air molecule the average speed of a smoke particle is

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

N molecules each of mass m of a gas

A

and

2 N

molecules each of mass

2 m

of gas

B

are contained in the same vessel which is maintained at temperature

T

. The mean square velocity of molecules of

B

type is

v^{2}

and the mean square rectangular component of the velocity of

A

type is denoted by

ω^{2}

. Then the value of

ω^{2} / v^{2}

is -

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Which of the following curves represent the variation of coefficient of volume expansion of an ideal gas at constant pressure?

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

An ideal gas equation can be written as,

P = \frac{ρ R T}{M_{0}}

where

ρ

and

M_{0}

are respectively,

MEDIUM

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

A mixture of hydrogen and oxygen has volume

500 {cm}^{3},

temperature

300 K,

pressure

400 k Pa

and mass

0.76 g .

The ratio of masses of oxygen to hydrogen will be:

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

The number density of molecules of a gas depends on their distance r from the origin as,

n (r) = n_{0} e^{- α r^{4}} .

Then the numer of molecules is proportional to:

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

What is the average kinetic energy of molecules of an ideal gas leaking freely through an orifice of a container which has

N

molecules at pressure

P

in volume

V

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

A mixture of 2 moles of helium gas (atomic mass = 4u)

,

and 1 mole of argon gas (atomic mass = 40 u) is kept at

300 K

in a container. The ratio of their rms speeds

[\frac{V_{r m s} (h e l i u m)}{V_{r m s} (a r g o n)}],

is close to:

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

Which of the following shows the correct relationship between the pressure

' P'

and density

ρ

of an ideal gas at constant temperature ?

EASY

Physics>Heat and Thermodynamics>Kinetic Theory of Gases>Kinetic Theory of Gases

The temperature of an ideal gas is increased from

100 K

400 K

. If the

r m s

speed of the gas molecule is

V

100 K

, then at

400 K

it becomes

Assertion: The potential energy of ideal gas is zero. Reason: At low pressure or high temperature the molecules are far apart and molecular interactions are negligible.

Important Questions on Kinetic Theory of Gases

Learn and Prepare for any exam you want !

Assertion: The potential energy of ideal gas is zero.

Reason: At low pressure or high temperature the molecules are far apart and molecular interactions are negligible.