Rate of diffusion

Definition

Rate of diffusion is the speed at which particles spread from areas of high concentration to areas of low concentration. It depends on factors such as temperature, particle size, and the medium through which diffusion occurs.

5 Must Know Facts For Your Next Test

1. The rate of diffusion increases with higher temperatures because particles move faster.
2. Lighter gas molecules diffuse more rapidly than heavier ones due to their lower mass.
3. Diffusion rates are influenced by the medium; gases diffuse faster in air than in liquids or solids.
4. Graham's Law states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass: $r_1 / r_2 = \sqrt{M_2 / M_1}$.
5. The rate of diffusion can be measured experimentally using setups like a diffusion tube or a porous barrier.

Review Questions

• How does temperature affect the rate of diffusion?
• According to Graham's Law, how does the molar mass of a gas influence its rate of diffusion?
• Why do lighter gas molecules diffuse faster than heavier ones?

Related terms

Effusion:

The process by which gas particles pass through a tiny opening from one container to another.

Graham's Law:

A law stating that the rate of effusion (or diffusion) of a gas is inversely proportional to the square root of its molar mass.

Kinetic Molecular Theory:

A theory that explains the behavior of gases based on the idea that they are composed of rapidly moving particles that collide elastically.