Question

Which statement best explains why different gases effuse at different rates?

Answer 1

Your answer is A. At a given pressure, gas particles with smaller masses move faster.

Hope this helps.

Answer 2

Answer: Different gases effuse at different rates because at a given temperature, gas particles with smaller masses move faster.

Explanation: The motion of particles in a gas depends on the kinetic energy of the gas particles which further depend on the temperature of the gas. Thus, the rate of gas given by Graham's law can only be stated when the two gases are at fixed temperature.

Graham's Law: This law states that the rate of effusion of gas is inversely proportional to the square root of its mass.

Mathematically,

$\frac{(Rate)_1}{(Rate)_2}=\sqrt{\frac{M_2}{M_1}}$

From the above relation, the gas particle with smaller mass will effuse faster at a given temperature.