Chapter 12, Problem 1STP

What is the ratio of diffusion rates for nitric oxide(NO) and nitrogen tetroxide $(N_2{O}_4)$ ?
A. 0.326
B. 0.571
C. 1.751
D. 3.066

Interpretation Introduction

Interpretation:

Correct option must be chosen regarding the ratio of diffusion rate of NO and N₂O₄.

Concept introduction:

According to Graham’s gas diffusion law, rate of diffusion is inversely proportional to the square root of the molecular weight.

Answer to Problem 1STP

Correct answer: Option C is correct.

Explanation of Solution

Reason for correct option: Option C is correct because molecular weight of NO is 30 and that of N₂O₄ is 92.

Thus ratio of rate of diffusion of NO to N₂O₄$=\sqrt{\raisebox{1ex}{$92$}\!\left/ \!\raisebox{-1ex}{$30$}\right.}=\sqrt{3.066}=\mathrm{1.751.}$

Conclusion

Reasons for incorrect options: From the calculations it can be seen that option A is incorrect as ratio of rate of diffusion of NO to N₂O₄ is not 0.326.

Option B is incorrect as ratio of rate of diffusion of NO to N₂O₄ is not 0.571.

Option D is incorrect as ratio of rate of diffusion of NO to N₂O₄ is not 3.066.