# 180ml of a hydrocarbon diffuses through a porous membrane in 15 minutes while 120ml of SO2 under similar conditions diffuses in 20 minutes. What is the molecular mass of hydrocarbon? and how

Dear student,

According to Graham's law of diffusion:

$\frac{{r}_{1}}{{r}_{2}}=\frac{\sqrt{{M}_{2}}}{\sqrt{{M}_{1}}}$

where

r = rate of diffusion
M = Molecular mass

So,

So, molecular mass of the hydrocarbon = 16 g/mol