The rate of diffusion of gas at a constant temperature and pressure

a) Directly proportional to density

b) Directly proportional to the square root of the molecular weight

c) Inversely proportional to the square root of the vapour density

d)Directly proportional to its RMS velocity

Given data :At constant temperature and pressure the rate of diffusion are

Concepts used: Graham's law of diffusion

Detailed solution:

According to Graham's law the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. At same conditions of temperature and pressure, the molar mass is proportional to the vapour density. So the rate of diffusion of different gases is inversely proportional to the square root of their mass densities and directly proportional to RMS velocity

Therefore the required answer is D