Explore popular questions from States of Matter: Gases and Liquids for JEE Advanced. This collection covers States of Matter: Gases and Liquids previous year JEE Advanced questions hand picked by experienced teachers.

## Chemistry

States of Matter: Gases and Liquids

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Q 1. Rate of diffusion of a gas is:

A

directly proportional to its density.

B

directly proportional to its molecular weight.

C

directly proportional to the square root of its molecular weight.

inversely proportional to the square root of its molecular weight.

##### Explanation

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Q 2. {tex} \mathrm { XmL } {/tex} of {tex} \mathrm { H } _ { 2 } {/tex} gas effuses through a hole in a container in 5 seconds. The time taken for the effusion of the same volume of the gas specified below under identical conditions is:

A

10 seconds : {tex} \mathrm { He } {/tex}

20 seconds : {tex} \mathrm { O } _ { 2 } {/tex}

C

25 seconds : {tex} \mathrm { CO } {/tex}

D

55 seconds : {tex} \mathrm { CO } _ { 2 } {/tex}

##### Explanation

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Q 3. A gas will approach ideal behaviour at

A

low temperature and low pressure.

B

low temperature and high pressure.

high temperature and low pressure.

D

high temperature and high pressure.

##### Explanation

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Q 4. At {tex} 100 ^ { \circ } \mathrm { C } {/tex} and {tex} 1 \mathrm { atm } , {/tex} if the density of liquid water is {tex} 1.0 \mathrm { g } \mathrm { cm } ^ { - 3 } {/tex} and that of water vapour is {tex} 0.0006 \mathrm { g } \mathrm { cm } ^ { - 3 } , {/tex} then the volume occupied by water molecules in {tex}1{/tex} litre of steam at that temperature is

A

{tex} 6 \mathrm { cm } ^ { 3 } {/tex}

B

{tex} 60 \mathrm { cm } ^ { 3 } {/tex}

{tex} 0.6 \mathrm { cm } ^ { 3 } {/tex}

D

{tex} 0.06 \mathrm { cm } ^ { 3 } {/tex}

##### Explanation

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Q 5. A mono-atomic ideal gas undergoes a process in which the ratio of {tex} P {/tex} to {tex} V {/tex} at any instant is constant and equals to {tex} 1 . {/tex} What is the molar heat capacity of the gas

A

{tex} \frac { 3 R } { 2 } {/tex}

{tex} 2 R {/tex}

C

{tex}0{/tex}

D

{tex} \frac { 5 R } { 2 } {/tex}

##### Explanation

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Q 6.

The root mean square velocity of an ideal gas to constant pressure varies with density as

A

B

C

##### Explanation

The expression of root mean square speed is

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Q 7.

A gas of volume 100 cc is kept in a vessel at pressure 10.4 Pa maintained at temperature . Now, if the pressure is increased to 105 Pa, keeping the temperature constant, then the volume of the gas becomes

10 cc

B

100 cc

C

1 cc

D

1000 cc

##### Explanation

Given

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Q 8.

For the non-zero value of the force of attraction between gas molecules, gas equation will be

B

C

D

##### Explanation

For mol of a real gas

When volume of molecules can’t be neglected,

when

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Q 9.

The compressibility factor for definite amount of van der Waal’s gas at and 100 atm is found to be 0.5. Assuming the volume of gas molecules negligible, the van der Waals’ constant for a gas is

B

C

D

##### Explanation

Now,

is negligible)

Since, is constant at given and , thus, discriminant is 0

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Q 10.

A 3:2 molar mixture of and is present in a vessel at 500 bar pressure. Due to hole in the vessel, the gas mixture leaks out. The composition of mixture effusing out initially is

A

B

C

##### Explanation

Molar ratio of and CO is 3:2, i.e., 300 bar and 200 bar, respectively

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Q 11.

Boltzmann constant is given by

A

B

C

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Q 12.

The compressibility factor for an ideal gas is

A

1.5

1

C

2

D

##### Explanation

Compressibility factor

For ideal gas, , so

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Q 13.

At 400 K, the root mean square (rms) speed of a gas (molecular weight = 40) is equal to the most probable speed of gas The molecular weight of the gas is

A

2

4

C

6

D

8

##### Explanation

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Q 14.

The value of van der Waals constant for the gases and are 1.360, 1.390, 4.170, and , respectively. The gas which can most easily be liquefied is

A

B

D

##### Explanation

The van der Waals constant is used in presence correction, and its value depends upon the intermolecular forces between the gas molecules The larger the value of for a gas, the more easily that gas van be liquefied

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Q 15.

A spherical air bubble is rising from the depth of a lake when pressure is atm and temperature is K. The percentage increase in the radius when it comes to the surface of a lake will be (Assume temperature and pressure at the surface to be, respectively, K and )

B

50%

C

40%

D

200%

##### Explanation

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Q 16.

If and are mole fraction, pressure fraction and volume fraction respectively of a gaseous mixture, then:

B

C

D

##### Explanation

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Q 17.

For the non-zero volume of the molecules, real gas equation for mol of the gas will be

A

B

C

Both (b) and (c) are true

##### Explanation

For mol of a real gas

When volume of molecules can’t be neglected,

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Q 18.

The quantity represents

Number of molecules in the gas

B

Mass of the gas

C

Number of moles of the gas

D

Translational energy of the gas

##### Explanation

Number of molecules

Where Boltzman constant

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Q 19.

The SI unit of the coefficient of viscosity is

A

C

D

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Q 20.

A quantity of gas is collected in a graduated tube over the mercury. The volume of the gas at is 50.0 mL and the level of the mercury in the tube is 100 mm above the outside mercury level. The barometer reads 750 mm. Volume at STP is

B

C

D

##### Explanation

Effective pressure

Use

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Q 21.

of gas effuses through a hole in a container in 5 s. The time taken for the effusion of the same volume of the gas specified below, under identical conditions, is

A

10 s, He

20 s,

C

25 s, CO

D

55 s,

##### Explanation

For the same volume diffused,

(Graham’s law)

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Q 22.

gas at STP contained in a flask was replaced by under same conditions. The weight of will be

A

Equal to that of

B

Half that of

Twice that of

D

One-fourth of

##### Explanation

of mol

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Q 23.

Which expression gives average speed of gas molecules?

A

B

D

##### Explanation

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Q 24.

The rate of diffusion of methane at a given temperature is twice that of a gas . The molecular weight of is

64

B

32

C

4

D

8

##### Explanation

(Graham’s law)

Or

Or

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Q 25.

Under similar conditions, which of the following gas will have same value of as ?

A

NO

C

D