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H₂S
Hydrogen sulfide
IUPAC : Hydrogen sulfide
OtherIndustrialMineral/geological
Colourless gas with a rotten-egg smell, toxic and flammable. Ubiquitous in petroleum and gas reservoirs (sour gas), volcanoes and organic decay. Intermediate of the Claus process (sulfur recovery).
3D ball-and-stick representation of Hydrogen sulfide (formula H₂S). Constituent atoms: H, S.
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Physical properties
Molar mass34.081 g/mol
State at 20 °Cgas
Density—
Melting point187.65 K (-85.50 °C)
Boiling point212.84 K (-60.31 °C)
Solubility (H₂O)0.4 g/100 mL à 20 °C
pKapKa₁ ≈ 7.0, pKa₂ ≈ 17
Structure
Crystal system—
3D render modeBall-and-stick
Uses and applications
- Claus process (industrial recovery of sulfur from H₂S)
- Chemical analysis (selective precipitation of metal sulfides)
- Petroleum industry (sour-gas treatment)
- Thermal-spring chemistry (balneotherapy)
Safety (GHS)
GHS02 · FlammableGHS04 · Gas under pressureGHS06 · Acute toxicityGHS09 · Environmental hazard
H statements : H220, H280, H330, H400
Extremely toxic by inhalation — fatal at ~500 ppm. Desensitises the sense of smell at high concentration (false sense of safety). Characteristic rotten-egg smell at low concentration.
Constituent elements
References
Sources : PubChem CID 402 · NIST Chemistry WebBook