How does molecular weight affect diffusion?
More molecular weight means
Thomas Graham, founder of Graham's Law of Diffusion, concluded that chemical has less molecular weight diffuse faster.
As a proof for Graham's idea NH3 and HCL tube reaction can be used.
Molecular weight of ammonia = 17 g/mol
Molecular weight of hydochloric acid = 36.5 g/mol
Ring of NH4Cl is formed near to HCl beacuse NH3 diffused faster however HCl is diffused slower because of its high molar mass.