Ammonium bisulfate

Ammonium bisulfate

Names
IUPAC name Ammonium hydrogen sulfate
Identifiers
CAS Number	7803-63-6
ChemSpider	23057
Jmol interactive 3D	Image
PubChem	16211166
RTECS number	WS990000
InChI InChI=1S/H3N.H2O4S/c;1-5(2,3)4/h1H3;(H2,1,2,3,4) Key: BIGPRXCJEDHCLP-UHFFFAOYSA-N InChI=1/H3N.H2O4S/c;1-5(2,3)4/h1H3;(H2,1,2,3,4) Key: BIGPRXCJEDHCLP-UHFFFAOYAA
SMILES [O-]S(=O)(=O)O.[NH4+]
Properties
Chemical formula	(NH4)HSO4
Molar mass	115.11 g/mol
Appearance	White solid
Density	1.78 g/cm^3
Melting point	147 °C (297 °F; 420 K)
Solubility in water	Very soluble
Solubility in other solvents	Soluble in methanol insoluble in acetone
Hazards
Safety data sheet	External MSDS
NFPA 704	0 3 0
Related compounds
Other anions	Ammonium thiosulfate Ammonium sulfite Ammonium sulfate Ammonium persulfate
Other cations	Sodium bisulfate Potassium bisulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Ammonium bisulfate, also known as ammonium hydrogen sulfate, is a white, crystalline solid with formula (NH₄)HSO₄. It is the product of the half-neutralization of sulfuric acid by ammonia.

Production

It is commonly collected as a byproduct of the "acetone cyanohydrin route" to the commodity chemical methyl methacrylate.^[1]

It can also be obtained by hydrolysis of sulfamic acid in aqueous solution, which produces the salt in high purity:

H₃NSO₃ + H₂O → [NH₄]⁺[HSO₄]⁻

It also arises by the thermal decomposition of ammonium sulfate:

(NH₄)₂SO₄ → (NH₄)HSO₄ + NH₃

Applications

It can be further neutralized with ammonia to form ammonium sulfate, a valuable fertilizer. It can be used as a weaker alternative to sulfuric acid, although sodium bisulfate is much more common.

References

1. William Bauer, Jr. "Methacrylic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_441.