If 0.44 g of a colourless oxide of nitrogen occupies 224 mL at 1520 mm Hg and 273°C , then the compound

P1=1520mm, V1=224mL,   T1=273+273=546K    At  N.T.P.  :  P2=760mm, V2=?,T2=273K.     Applying gas equation, we have :               P1V1T1=P2V2T2Substituting the values, we get :V2=1520×224×273760×546=224mL.Thus 224mL oxide of nitrogen weighs =0.44g∴22400mL  weighs        =0.44224×22400=44g ∴ Gram molar mass of oxide of nitrogen=44   Gas =N2O because molar mass of N2O=(2×14)+16=44.