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
