Chemical, physical and thermal properties of Hydrogen - H2 :
| Molecular Weight | 2.016 |
| Specific Gravity | 0.070 |
| Specific Volume (ft3/lb, m3/kg) | 194, 12.1 |
| Density of liquid at atmospheric pressure (lb/ft3, kg/m3) | 4.43, 71.0 |
| Absolute Viscosity (lbm/ft s, centipoises) | 6.05 10-6, 0.009 |
| Sound velocity in gas (m/s) | 1315 |
| Specific Heat - cp - (Btu/lboF or cal/goC, J/kgK) | 3.42, 14310 |
| Specific Heat Ratio - cp/cv | 1.405 |
| Gas constant - R - (ft lb/lboR, J/kgoC) | 767, 4126 |
| Thermal Conductivity (Btu/hr ft oF, W/moC) | 0.105, 0.182 |
| Boiling Point - saturation pressure 14.7 psia and 760 mm Hg - (oF, oK) | -423, 20.4 |
| Latent Heat of Evaporation at boiling point (Btu/lb, J/kg) | 192, 447000 |
| Freezing or Melting Point at 1 atm (oF, oC) | -434.6, -259.1 |
| Latent Heat of Fusion (Btu/lb, J/kg) | 25.0, 58000 |
| Critical Temperature (oF, oC) | -399.8, -240.0 |
| Critical Pressure (psia, MN/m2) | 189, 1.30 |
| Critical Volume (ft3/lb, m3/kg) | 0.53, 0.033 |
| Flammable | yes |
| Heat of combustion (Btu/ft3, Btu/lb, kJ/kg) | 320, 62050, 144000 |
- values at 25oC (77oF, 298 K) and atmospheric pressure
