Hydrogen sulfide - H2S

Hydrogen sulfide is a colourless and very poisonous gas that is heavier than air. It is used in a few applications such as rust protection of iron and carbon steel objects. It is also used to calibrate environmental emissions monitoring.

The gas is very flammable and toxic when inhaled, and it smells like rotten eggs.


  • Molecular weight:

    34.081 g/mol

  • Gaseous phase:

    Gas density (1.013 bar at boiling point): 1.997 kg/m3
    Gas density 1.013 bar and 15 °C (59 °F)): 1.4534 kg/m3

  • Solid phase:

    Melting point: -85.7 °C

  • Liquid phase:

    Boiling point (1.013 bar): -60.3 °C
    Liquid density (1.013 bar at boiling point): 949.2 kg/m3

  • Critical point:

    Critical temperature: 99.95 °C
    Critical pressure: 90 bar
    Critical density: 347.28 kg/m3