Ammonium bisulfate, also known as ammonium hydrogen sulfate, is a white,

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

line solid with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...

(NH₄)HSO₄. This salt is the product of the half-neutralization of sulfuric acid by

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

Production

It is commonly collected as a byproduct of the "acetone cyanohydrin route" to the commodity chemical

methyl methacrylate Methyl methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA ...

. It can also be obtained by hydrolysis of

sulfamic acid Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, sulphamic acid and sulfamidic acid, is a molecular compound with the formula H3NSO3. This colourless, water-soluble compound finds many applications. Sulfami ...

in aqueous solution, which produces the salt in high purity: : H₃NSO₃ + H₂O → H₄sup>+ SO₄sup>− It also arises by the thermal decomposition of

ammonium sulfate Ammonium sulfate (American English and international scientific usage; ammonium sulphate in British English); (NH4)2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen a ...

: : (NH₄)₂SO₄ → (NH₄)HSO₄ + NH₃

Applications

It can be further neutralized with ammonia to form ammonium sulfate, a valuable

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

. It can be used as a weaker alternative to sulfuric acid, although

sodium bisulfate Sodium bisulfate, also known as sodium hydrogen sulfate, is the sodium salt of the bisulfate anion, with the molecular formula NaHSO4. Sodium bisulfate is an acid salt formed by partial neutralization of sulfuric acid by an equivalent of sodium ...

is much more common.

Natural occurrence

A related compound of the (NH₄)₃H(SO₄)₂ formula, occurs as the rare mineral

letovicite Letovicite () is an ammonium sulfate mineral with composition (NH4)3H(SO4)2 (IUPAC: triammonium sulfate hydrogensulfate, Nickel–Strunz classification 07.AD.20). It is a rare colorless or white monoclinic secondary mineral formed during the burn ...

, known from coal fire environments.

References

{{inorganic-compound-stub Ammonium compounds Sulfates