Graham’s Law of Effusion

Graham’s Law of Effusion describes the relationship between a gas’ rate of effusion to be

Rate α Temperature

Rate α 1/M

a) inversely proportional to a gas’ molecular mass

• Simply put, a heavy gas moves slower than a ligher one.

b) directly proportional to a gas’ temperature

• At higher temperatures, gas molecules have more kinetic energy and therefore greater motion, hence the faster rate of diffusion.