Question

Estimate the molar mass of a gas that effuses at 1.80 times the effusion rate of carbon dioxide. answer in units of g/mol.

Answer 1

From Grahams Law the rates of effusion of two gases are inversely proportional to the square roots of their molar masses at the same temperature and pressure.
Therefore; R1/R2 = √mm2/√mm1
The molecular mass of Carbon dioxide is 44 g
Hence;  1.8 = √(44/x
             3.24 = 44/x
                x = 44/3.24
                   = 13.58 
Therefore, the molar mass of the other gas is 13.58 g/mol