Chapter 12, Problem 39A

Interpretation Introduction

Interpretation:

The comparison between diffusion and effusion needs to be explained.

Concept introduction:

Diffusion is ability of gas to mix with each other in absence of barrier while effusion is ability of gas to travel through a small opening.

Answer to Problem 39A

In effusion, particles move faster than diffusion. Both effusion and diffusion rates are inversely proportional to the molecular mass of gas.

Explanation of Solution

Both effusion and diffusion rate explained by Graham’s Law.

$R\propto \frac{1}{\sqrt{M}}or\frac{R_1}{R_2}=\sqrt{\frac{M_2}{M_1}}$.

Where $M_1\&M_2$ are masses of gas.

In other words the rate of effusion of gas is inversely proportional to square root of density or molar mass of gas.

Thus $\frac{R_1}{R_2}=\sqrt{\frac{D_2}{D_1}}$ where $D_1,D_2$ are density of gas.

Conclusion

Diffusion and effusion are property of gas.