Ammonium bisulfate, also known as ammonium hydrogen sulfate, is a white, crystalline solid with the formula (NH4)HSO4. This salt 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.
Natural occurrence
A related compound of the (NH4)3H(SO4)2 formula, occurs as the rare mineral letovicite, known from coal fire environments.[2][3]
References
- ^ William Bauer, Jr. "Methacrylic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_441.
- ^ "Letovicite".
- ^ "List of Minerals". 21 March 2011.