Question

Light gases diffuse faster than heavy gases . Why?

Answer 1

Dear Student,

Light diffuses faster as compared to heavy gases.

According to Graham's Law, rate of diffusion is inversely proportional to the density of gases.

$\text{Rate of diffusion α}\frac{1}{\sqrt{\mathrm{density}}}$

Volume gases contain same number of particles at given T and P. So, rate of diffusion is inversely proportional to the Molar mass of gases.

$\text{Rate of diffusion α}\frac{1}{\sqrt{\mathrm{Molar}\mathrm{mass}}}$
So, Lower the mass of the gas higher will be the rate of diffusion.

Regards