Ammonium hydrosulfide

Ammonium hydrosulfide
IUPAC name	ammonium hydrosulfide
Other names	ammonium bisulfide ammonium hydrogen sulfide
Identifiers
CAS number	[12124-99-1]
RTECS number	BS4900000
Properties
Molecular formula	H5NS
Molar mass	51.111 g/mol
Appearance	Yellow-orange fuming liquid.
Density	? g/ml
Solubility in water	Infinitely soluble
Hazards
Main hazards	Toxic
NFPA 704	3 3 0
R-phrases	R11, R23, R24, R25.
Related compounds
Other anions	Ammonium sulfate
Other cations	Sodium hydrosulfide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references

Ammonium hydrosulfide is the chemical compound with the formula (NH₄)SH. It is the salt derived from the ammonium cation and the hydrosulfide anion. By passing hydrogen sulfide mixed with a slight excess of ammonia gives the colourless, micaceous crystals. It dissolves readily in water but is partially dissociated in solution. The compound is encountered mainly as a solution, not as the salt. It is corrosive agent in oil refineries, where it is generated in the handling of hydrogen sulfide.

[edit] History

Ammonium sulfide is commercially available as an aqueous solution, though it is rather expensive. It can also be prepared by passing hydrogen sulfide gas through concentrated ammonia solution, and warming the flask slightly.^[1]

A 1895 report describes that passing hydrogen sulfide into a concentrated aqueous ammonia solution at ordinary temperature gives (NH₄)₂S·2NH₄HS, which, on cooling to 0 °C and adding more hydrogen sulfide forms (NH₄)₂S·12NH₄HS.^[2] An ice-cold solution of this substance kept at 0°C and having hydrogen sulfide continually passed through it gives the hydrosulfide.

As noted also by the Bloxam paper, several complex polysulfides of ammonium can be isolated. Such species arise via the addition of elemental sulfur to "ammonium sulfide:"

2 (NH₄)SH + 1/2 S₈ (NH₄)₂S₄ + H₂S

[edit] Stink bombs

The common "stink bomb" consists of a solution of ammonium sulfide in water, sealed inside a glass ampoule. When the glass is broken, ammonia and hydrogen sulfide gases, both of which have a powerful unpleasant smell, are released from the solution. This conversion illustrates the ease of the following equilibrium:

(NH₄)SH NH₃ + H₂S

[edit] Occurrence on gas giants

In addition to water and ammonia, the clouds in the atmospheres of the gas giant planets contain ammonium sulfides. The reddish-brownish clouds, which have been exposed to prolonged sunlight are attributed to polysulfides.^[3]

[edit] References

1. ^ Goodman, J. T.; Rauchfuss, T. B., (2002). "Tetraethylammonium-tetrathioperrhenate [Et₄N][ReS₄]". Inorganic Syntheses 33: 107–110. 
2. ^ W. P. Bloxam (1895). "The Sulphides and Polysulphides of Ammonium". J. Chem. Soc., Trans. 67: 283. doi:10.1039/CT8956700277. 
3. ^ Jupiter :: Cloud composition - Britannica Online Encyclopedia

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