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

Ammonium bisulfate
Hydrogen sulfate.svg
Ball-and-stick model of an ammonium cation (left) and a bisulfite anion (right)
Sample of ammonium bisulfate.jpg
IUPAC name
Ammonium hydrogen sulfate
3D model (JSmol)
ECHA InfoCard 100.029.332
RTECS number WS990000
Molar mass 115.11 g/mol
Appearance White solid
Density 1.78 g/cm3
Melting point 147 °C (297 °F; 420 K)
Very soluble
Solubility in other solvents Soluble in methanol
insoluble in acetone
Safety data sheet External MSDS
NFPA 704
Flammability code 0: Will not burn. E.g. waterHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
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


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


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.


  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.