A gas of mass 32gms has a volume of 20 litres

A gas of mass 32gms has a volume of 20 litres at S.T.P. Calculate the gram molecular weight of the gas.

20 l of gas at STP have a mass of 32 g
∴ 22.4 l of gas at STP would have a mass of 22.4 ×32/20
∴ gram molecular weight = 35.84 g.