Properties of common gases (14.696 kPa, 68°F)

From CRC Handbook (1973), with permission

Common
Name

Chemical Formula

Molecular weight

Density,
lbm/ft3

Viscosity,
lbm/ft·s

Hydrogen

H2

2.02

0.00523

0.0608

Helium

He

4.00

0.0104

0.1322

Water vapor

H20

18.02

0.0468

0.0682

Air (dry)

-

28.96

0.0752

0.1235

Carbon dioxide

CO2

44.01

0.114

0.0997

Carbon monoxide

CO

28.01

0.0727

0.1222

Nitrogen

N2

28.02

0.0727

0.1184

Oxygen

O2

32.00

0.0831

0.1345

Methane

CH4

16.04

0.0416

0.0901