QJEEM21Ph760b: JEE Main 2021 Physics - Class 11 JEEM21Ph760b Solution: Calculate the value of mean free path ( ) for oxygen molecules…

Question

Verified Solution • 2025–26 Session moderate

Calculate the value of mean free path (

\lambda

) for oxygen molecules at temperature 27

^\circ

C and pressure 1.01

\times

10⁵ Pa. Assume the molecular diameter 0.3 nm and the gas is ideal. (k = 1.38

\times

10^{$-$ 23} JK^{$-$ 1})

Accepted Answer

{I_{mean}} = {{RT} \over {\sqrt 2 \pi {d^2}{N_A}P}}

= {{1.38 \times 300 \times {{10}^{ - 23}}} \over {\sqrt 2 \times 3.14 \times {{(0.3 \times {{10}^{ - 9}})}^2} \times 1.01 \times {{10}^5}}}

= 102 \times {10^{ - 9}}

m

= 102

nm

Step-by-Step Verified Solution