Which of the following best describes the difference between effusion and diffusion?

• A. Effusion is the movement of gas particles through a small hole into a vacuum, while diffusion is the mixing of gas particles throughout a space.
• B. Effusion and diffusion are identical processes with no differences.
• C. Effusion occurs only in liquids, while diffusion occurs only in gases.
• D. Effusion is the process of gas particles spreading out in a room, while diffusion is the escape of gas through a small hole.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definitions of effusion and diffusion in the context of gases. Effusion refers to the process where gas particles pass through a tiny hole from one container to another without collisions between particles during passage.
2. Step 2: Recognize that diffusion is the process by which gas particles spread out and mix evenly throughout a space due to their random motion and collisions with other particles.
3. Step 3: Note the key difference: effusion involves gas particles moving through a small opening into a vacuum or lower pressure area, while diffusion involves the mixing of gases within a space without the need for an opening.
4. Step 4: Eliminate incorrect options by checking if they contradict these definitions, such as effusion occurring only in liquids or effusion and diffusion being identical.
5. Step 5: Conclude that the best description is that effusion is the movement of gas particles through a small hole into a vacuum, while diffusion is the mixing of gas particles throughout a space.