Question

Why would molecules of a gas diffuse more rapidly than those of a liquid?

Answer 1

Gas molecules diffuse faster than liquid molecules because they have more kinetic energy and are smaller than liquid molecules. If you were to add heat to a gas or liquid the amount of kinetic energy in the molecules increases causing the rate of diffusion to speed up.

Answer 2

Gas molecules diffuse more rapidly than molecules of liquid because gas molecules have more kinetic energy, and are smaller than liquid molecules.