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Hydrogen sulphide

Hydrogen sulfide
Skeletal formula of hydrogen sulfide with two dimensions
Ball-and-stick model of hydrogen sulfide
Spacefill model of hydrogen sulfide
Names
Systematic IUPAC name
Hydrogen sulfide
Other names
  • Dihydrogen monosulfide
  • Dihydrogen sulfide
  • Sewer gas
  • Sulfane
  • Sulfurated hydrogen
  • Sulfureted hydrogen
  • Sulfuretted hydrogen
  • Sulfur hydride
  • Hydrosulfuric acid
  • Hydrothionic acid
  • Sulfhydric acid
Identifiers
7783-06-4 YesY
3D model (Jmol) Interactive image
3DMet B01206
3535004
ChEBI CHEBI:16136 YesY
ChEMBL ChEMBL1200739 N
ChemSpider 391 YesY
ECHA InfoCard 100.029.070
EC Number 231-977-3
303
KEGG C00283 YesY
MeSH Hydrogen+sulfide
PubChem 402
RTECS number MX1225000
UNII YY9FVM7NSN YesY
UN number 1053
Properties
H2S
Molar mass 34.08 g·mol−1
Appearance Colorless gas
Odor Rotten eggs
Density 1.363 g dm−3
Melting point −82 °C (−116 °F; 191 K)
Boiling point −60 °C (−76 °F; 213 K)
4 g dm−3 (at 20 °C)
Vapor pressure 1740 kPa (at 21 °C)
Acidity (pKa) 7.0
Basicity (pKb) 12.9
−25.5·10−6 cm3/mol
1.000644 (0 °C)
Structure
C2v
Bent
0.97 D
Thermochemistry
1.003 J K−1 g−1
206 J mol−1 K−1
−21 kJ mol−1
Hazards
Safety data sheet External MSDS
Extremely Flammable F+ Very Toxic T+ Dangerous for the Environment (Nature) N
R-phrases R12, R26, R50
S-phrases (S1/2), S9, S16, S36, S38, S45, S61
NFPA 704
Flammability code 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g., propane Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point −82.4 °C (−116.3 °F; 190.8 K)
232 °C (450 °F; 505 K)
Explosive limits 4.3–46%
Lethal dose or concentration (LD, LC):
  • 713 ppm (rat, 1 hr)
  • 673 ppm (mouse, 1 hr)
  • 634 ppm (mouse, 1 hr)
  • 444 ppm (rat, 4 hr)
  • 600 ppm (human, 30 min)
  • 800 ppm (human, 5 min)
US health exposure limits (NIOSH):
PEL (Permissible)
C 20 ppm; 50 ppm [10-minute maximum peak]
REL (Recommended)
C 10 ppm (15 mg/m3) [10-minute]
IDLH (Immediate danger)
100 ppm
Related compounds
Related hydrogen chalcogenides
Related compounds
Phosphine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Hydrogen sulfide is the chemical compound with the formula H
2
S
. It is a colorless gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable.

Hydrogen sulfide often results from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion. H
2
S
also occurs in volcanic gases, natural gas, and in some sources of well water. The human body produces small amounts of H
2
S
and uses it as a signaling molecule.

Swedish chemist Carl Wilhelm Scheele is credited with having discovered hydrogen sulfide in 1777.

The British English spelling of this compound is hydrogen sulphide, but this spelling is not recommended by the International Union of Pure and Applied Chemistry or the Royal Society of Chemistry.

Hydrogen sulfide is slightly heavier than air; a mixture of H
2
S
and air can be explosive. Hydrogen sulfide and oxygen burn with a blue flame to form sulfur dioxide (SO
2
) and water. In general, hydrogen sulfide acts as a reducing agent, especially in the presence of base, which forms SH.


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