Which statement best describes effusion?

• A. The condensation of a gas into a liquid at low temperature.
• B. The mixing of two gases due to random molecular motion.
• C. The process by which gas molecules escape through a tiny hole into a vacuum.
• D. The separation of a mixture into its individual components by filtration.

Answer: (C)

Verified step by step guidance

1. Understand that effusion refers to the movement of gas molecules through a very small hole or tiny opening without collisions between molecules at the opening.
2. Recognize that effusion occurs when gas molecules pass through a tiny hole from one container to another, typically into a vacuum or an area of lower pressure.
3. Differentiate effusion from diffusion, which is the mixing of gases due to random molecular motion, and from condensation, which is the phase change from gas to liquid.
4. Note that effusion does not involve the separation of mixtures by filtration, which is a physical separation technique for solids and liquids.
5. Summarize that the best description of effusion is: 'The process by which gas molecules escape through a tiny hole into a vacuum.'