Molecular weights of common gases


Incl molecular weight of air, ammonia, natural gas, water vapor

Gas Molecular weight g/mol
Acetylene 26.04
Air 28.97
Ammonia 17.03
Benzene 78.11
Carbon dioxide 44.01
Carbon monoxide 28.01
Chlorine 70.91
Ethane 30.07
Ethyle Alcohol 46.07
Ethyle Chloride 64.52
Ethylene 28.05
Hydrogene 2.02
Methane 16.04
Methyl Alcohol 32.04
Methyl Chloride 50.49
Natural Gas 18.82
Nitrogen 28.02
Oxygen 32
Propane 44.09
Propylene 42.08
Water vapor 18.02

Source : Chemical Engineering, 1974