1. The densities of two gasses are in the ratio of 1: 16. The ratio of their rates of diffusion is

a) 16:1

b) 4:1

c) 1:4

d) 1:16

Discussion

Explanation: \[\frac{r_{1}}{r_{2}}= \sqrt{\frac{d_{2}}{d_{1}}} = \sqrt{\frac{16}{1}} = 4:1\]

2. At what temperature, the rate of effusion of \[N_{2}\] would be 1.625 times than that of \[SO_{2}\] at 50^{o} C ?

a) 110 K

b) 173 K

c) 373 K

d) 273 K

Discussion

Explanation:

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

a) 64.0

b) 32.0

c) 40.0

d) 80.0

Discussion

Explanation: \[\frac{2}{1}= \sqrt{\frac{M_{x}}{16}} \]

M

_{x}= 64

4. X ml of \[H_{2}\] gas effuse through a hole in a container in 5 seconds. The time taken for the effusion of the same volme of the gas specified below under identical conditions is

a) 10 seconds : He

b) 20 seconds :\[O_{2}\]

c) 25 seconds : CO

d) 55 seconds :\[CO_{2}\]

Discussion

Explanation:

5. The rate of diffusion of a gas having molecular weight just double of nitrogen gas is \[56mls^{-1}\] . The rate of diffusion of nitrogen will be

a) \[79.19mls^{-1}\]

b) \[12.0mls^{-1}\]

c) \[56.0.0mls^{-1}\]

d) \[90.0mls^{-1}\]

Discussion

Explanation:

6. Which pair of the gaseous species diffuse through a small jet with the same rate of diffusion at same P and T

a) NO, CO

b) \[NO,CO_{2}\]

c) \[NH_{3},PH_{3}\]

d) \[NO,C_{2}H_{6}\]

Discussion

Explanation: NO and C

_{2}H

_{6}both have same molecular weight. Hence their rate of diffusion will be same

7. The rate of diffusion of \[SO_{2},CO_{2},PCI_{3} and SO_{3}\] are in the following order

a) \[PCI_{3}> SO_{3}>SO_{2}>CO_{2}\]

b) \[CO_{2}>SO_{2}>PCI_{3}> SO_{3}\]

c) \[SO_{2}> SO_{3}>PCI_{3}>CO_{2}\]

d) \[CO_{2}>SO_{2}> SO_{3}>PCI_{3}\]

Discussion

Explanation: \[Rate \propto \sqrt{\frac{1}{M}} \] The smaller the value of M the more is the rate of diffusion

8. Which of the following expression correctly represents the relationship between the average molar kinetic energy \[\overline{K}E\] of CO and \[N_{2}\] molecules at the same temperature

a) \[\overline{K}E_{CO}=\overline{K}E_{N_{2}}\]

b) \[\overline{K}E_{CO}>\overline{K}E_{N_{2}}\]

c) \[\overline{K}E_{CO}<\overline{K}E_{N_{2}}\]

d) Can not be predicted unless the volumes of the gases are not given

Discussion

Explanation: At the same temperature KE is the same, as KE \[\propto\] T

9. Kinetic theory of gases presumes that the collisions between the molecules to be perfectly elastic because

a) the gas molecules are tiny particles and not rigid in nature

b) the temperature remains constant irrespective of collision

c) collision will not split the molecules

d) the molecules are large particleand rigid in nature

Discussion

Explanation: The gas molecules are tiny particles and not rigid in nature rather they are perfect elastic bodies

10. The average kinetic energy of an ideal gas per molecule in SI unit at 25° C will be

a) \[6.17 × 10^{-21}kJ\]

b) \[6.17 × 10^{-21}J\]

c) \[6.17 × 10^{-20}J\]

d) \[7.16 × 10^{-20}J\]

Discussion

Explanation: