Question

Given below are two statements :
Statement (I) : The mean free path of gas molecules is inversely proportional to square of molecular diameter.
Statement (II) : Average kinetic energy of gas molecules is directly proportional to absolute temperature of gas.
In the light of the above statements, choose the correct answer from the option given below:

• A. Statement I is false but Statement II is true
• B. Statement I is true but Statement II is false
• C. Both Statement I and Statement II are false
• D. Both Statement I and Statement II are true

Answer 1

Answer: (D)

Both Statement I and Statement II are true

Answer 2

The mean free path ($\lambda$) of gas molecules is given by:
$\lambda = \frac{RT}{\sqrt{2} \pi d^2 N_A P}.$
Here, $\lambda \propto \frac{1}{d^2}$, verifying Statement (I).
The average kinetic energy of gas molecules is:
$KE = \frac{f}{2} nRT,$
where $KE \propto T$, confirming Statement (II).
Thus, both Statement I and Statement II are correct.