Hydrogen sulfide
From Simple English Wikipedia, the free encyclopedia
| Hydrogen sulfide | |
|---|---|
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| General | |
| Systematic name | Hydrogen sulfide, sulfane |
| Other names | Sulfuretted hydrogen |
| Molecular formula | H2S |
| Molar mass | 34.082 g/mol |
| Appearance | Colorless gas. |
| CAS number | |
| Properties | |
| Density and phase | 1.363 g/L, gas. |
| Solubility in water | 0.25 g/100 ml (40°C) |
| Melting point | −82.30°C (190.85 K) |
| Boiling point | −60.28°C (212.87 K) |
| Acidity (pKa) | 6.89 19±2 (See Text) |
| Structure | |
| Molecular shape | Bent. |
| Dipole moment | 0.97 D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Highly toxic, highly flammable. |
| NFPA 704 |
4
4
0
|
| Flash point | −82.4°C |
| R/S statement | R: |
| RTECS number | MX1225000 |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Inorganic derivatives | sodium sulfide sodium hydrosulfide |
| Organic derivatives | dimethyl sulfide |
| Related hydrogen compounds | water hydrogen selenide hydrogen telluride |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
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Hydrogen sulfide (hydrogen sulphide in British English), H2S, is a colorless, toxic, flammable gas that is responsible for the foul smell of rotten eggs and flatulence. It often results when bacteria break down organic matter in the absence of oxygen. This happens in swamps, and sewers (alongside the process of anaerobic digestion). It also occurs in volcanic gases, natural gas and some well waters. This is the smell that people often think to be that of sulfur. But sulfur itself does not smell.
Hydrogen sulfide is also known as sulfane, sulfur hydride, sour gas, sulfurated hydrogen, hydrosulfuric acid, sewer gas and stink damp. IUPAC accepts the names "hydrogen sulfide" and "sulfane". When people speak of more complicated compounds they always use the term "sulfane".
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[edit] Occurrence
Small amounts of hydrogen sulfide can be found in crude petroleum but natural gas can contain up to 28%. Volcanoes and hot springs emit some H2S, where it probably arises via the hydrolysis of sulfide minerals, i.e. MS + H2O to give MO + H2S.
Normal average concentration in clean air is about 0.0001-0.0002 ppm.
[edit] Safety
Hydrogen sulfide is a highly toxic and flammable gas. Because it is heavier than air it tends to accumulate at the bottom of poorly ventilated spaces.
[edit] Toxicity
Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of hydrogen cyanide.
[edit] Reference
- "Hydrogen Sulfide", Committee on Medical and Biological Effects of Environmental Pollutants, University Park Press, 1979, Baltimore. ISBN 0-8391-0127-9
[edit] External links
- International Chemical Safety Card 0165
- Concise International Chemical Assessment Document 53
- National Pollutant Inventory - Hydrogen sulfide fact sheet
- NIOSH Pocket Guide to Chemical Hazards
- MSDS safety data sheet
- Abstract of survey article on H2S as used by the body, by P. Kamoun
- Computational Chemistry Wiki
