Volume occupied by one mole of any gas at STP is called gram molar volume. The value of gram molar volume is 22.4 litres.
Thus, Volume of 1 mole of H2 or 2 g of H2 at STP = 22.4 lit
Volume of 16 g(\(\frac 12\) mole) of O2 = 11.2 lit
Volume of 7 g (\(\frac 14\) mole) of N2 = 5.6 lit
Volume of 0.5 g (\(\frac 14\) mole) of H2 = 5.6 lit
Volume of 16 g (1 mole) of CH4 = 22.4 lit
