Molecular weight of H2 = 2 × 1 = 2 u
Molecular weight of O2 = 2 × 16 = 32 u
Molecular weight of Cl2 = 2 × 35.5 = 71 U
Molecular weight of CO2 = 12 + 2 × 16 = 44 u
Molecular weight of CH4 = 12 + 4 × 1 = 16 u
Molecular weight of C2H6 = 2 × 12 + 6 × 1= 30 u
Molecular weight of C2H4 = 2 × 12 + 4 × 1= 28 u
Molecular weight of NH3 = 14 + 3 × 1 = 17 u
Molecular weight of CH3OH = 12 + 4 × 1 + 16 = 32 u