Which one or more of the following statements are true? (a) O2 will effuse faster than Cl2. (b) Effusion and diffusion are different names for the same process. (c) Perfume molecules travel to your nose by the process of effusion. (d) The higher the density of a gas, the shorter the mean free path.

Verified step by step guidance

1. Identify the concept of effusion and diffusion: Effusion is the process by which gas molecules escape through a tiny hole into a vacuum, while diffusion is the spreading of gas molecules throughout a container or space.
2. Apply Graham's Law of Effusion to statement (a): According to Graham's Law, the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Compare the molar masses of O2 and Cl2 to determine which effuses faster.
3. Evaluate statement (b) by clarifying the difference between effusion and diffusion: Effusion involves gas molecules passing through a small opening, while diffusion involves the mixing of gases in a space.
4. Consider statement (c) by understanding how perfume molecules travel: Perfume molecules spread through the air by diffusion, not effusion, as they mix with air molecules and travel to your nose.
5. Analyze statement (d) by considering the relationship between gas density and mean free path: The mean free path is the average distance a molecule travels before colliding with another molecule. Higher density means more molecules in a given volume, leading to a shorter mean free path.

Key Concepts

Graham's Law of Effusion

Graham's Law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. This means lighter gases effuse faster than heavier gases. For example, O2 (molar mass ~32 g/mol) will effuse faster than Cl2 (molar mass ~71 g/mol) because it is lighter.

Diffusion vs. Effusion

Diffusion is the process by which gas molecules spread out to occupy a space uniformly, while effusion is the escape of gas molecules through a tiny opening into a vacuum. Although both processes involve the movement of gas particles, they are distinct in their mechanisms and conditions.

Mean Free Path

The mean free path is the average distance a gas molecule travels between collisions with other molecules. It is inversely related to the density of the gas; as density increases, the mean free path decreases due to more frequent collisions. Thus, higher density gases have shorter mean free paths.