Chapter 12.1, Problem 1PP

Interpretation Introduction

Interpretation: The ratio of effusion rate for nitrogen and neon needs to be determined.

Concept Introduction: Graham's law of effusion states that the rate of effusion for a gas is inversely proportional to the square root of its molar mass.

Answer to Problem 1PP

The ratio of effusion rate for nitrogen and neon is 0.849.

Explanation of Solution

Graham's law of effusion states that the rate of effusion for a gas is inversely proportional to the square root of its molar mass.

  $\text{R}\text{a}\text{t}\text{e}\text{o}\text{f}\text{e}\text{f}\text{f}\text{u}\text{s}\text{i}\text{o}\text{n}\propto \frac{1}{\sqrt{\text{m}\text{o}\text{l}\text{a}\text{r}\text{m}\text{a}\text{s}\text{s}}}$

Molar mass of N₂ = 28.02 g/mol

Molar mass of Ne = 20.18 g/mol

So, the ratio of the rate of effusion for nitrogen and neon is

  $\frac{\text{R}\text{a}\text{t}\text{e}({\text{N}}_2)}{\text{R}\text{a}\text{t}\text{e}(\text{N}\text{e})}=\frac{\sqrt{\text{m}\text{o}\text{l}\text{a}\text{r}\text{m}\text{a}\text{s}\text{s}\text{o}\text{f}\text{N}\text{e}}}{\sqrt{\text{m}\text{o}\text{l}\text{a}\text{r}\text{m}\text{a}\text{s}\text{s}\text{o}\text{f}{\text{N}}_2}}=\frac{\sqrt{20.18}}{\sqrt{28.02}}=0.849$