Chapter 19, Problem 4STP

Interpretation Introduction

Interpretation:

Four different gases are there in four containers. The gas with fastest rate of effusion is to be found out.

Concept introduction:

It is based on Graham’s Law of effusion. According to it,

$\begin{array}{l}Rateofeffusion\propto \sqrt{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$M$}\right.}\\ where\\ Mismolarmassofgas\end{array}$

Answer to Problem 4STP

Explanation of Solution

The rate of effusion is inversely proportional to molar mass, therefore the gas having least molar mass will have fastest rate of effusion.

$\begin{array}{l}{M}_{Xe}=131\\ M_{He}=4\\ M_{N_2}=28\\ M_{C{O}_2}=44\end{array}$

Therefore, helium gas will have fastest rate of effusion.

Conclusion

As helium gas has fastest rate of effusion, option B is correct and rest are incorrect.