Question

Which of the following pairs will diffuse at the same rate through a porous plug.

(a) CO, NO₂

(b) NO₂, CO₂

(c) NH₃, PH₃

(d) NO, C₂H₆

Answer 1

Correct option is (d) NO, C₂H₆

Graham's law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight.

The molecular mass of NO and C₂H₆ is the same. Hence, both diffuse with the same rate of diffusion.