ammonium bisulfate
{{chembox
| Verifiedfields = changed
| verifiedrevid = 476993091
| ImageFileL1 = Ammonium.svg
| ImageSizeL1 = 75
| ImageFileR1 = Hydrogen sulfate.svg
| ImageSizeR1 = 85
| ImageFile2 = Ammonium-bisulfate-3D-balls.png
| ImageName2 = Ball-and-stick model of an ammonium cation (left) and a bisulfite anion (right)
| ImageFile3 = Sample of ammonium bisulfate.jpg
| IUPACName = Ammonium hydrogen sulfate
| OtherNames =
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 23057
| InChI = 1/H3N.H2O4S/c;1-5(2,3)4/h1H3;(H2,1,2,3,4)
| SMILES = [O-]S(=O)(=O)O.[NH4+]
| InChIKey = BIGPRXCJEDHCLP-UHFFFAOYAA
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/H3N.H2O4S/c;1-5(2,3)4/h1H3;(H2,1,2,3,4)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = BIGPRXCJEDHCLP-UHFFFAOYSA-N
| CASNo = 7803-63-6
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 6218R7MBZB
| PubChem = 16211166
| RTECS = WS990000
}}
|Section2={{Chembox Properties
| Formula = (NH4)HSO4
| MolarMass = 115.11 g/mol
| Appearance = White solid
| Density = 1.78 g/cm3
| MeltingPtC = 147
| BoilingPt =
| Solubility = Very soluble
| SolubleOther = Soluble in methanol
insoluble in acetone
| Solvent = other solvents
}}
|Section3={{Chembox Hazards
| ExternalSDS = [http://msds.chem.ox.ac.uk/AM/ammonium_bisulfate.html External MSDS]
| FlashPt =
| AutoignitionPt =
| NFPA-H = 3 | NFPA-F = 0 | NFPA-R = 0
}}
|Section8={{Chembox Related
| OtherAnions = Ammonium thiosulfate
Ammonium sulfite
Ammonium sulfate
Ammonium persulfate
| OtherCations = Sodium bisulfate
Potassium bisulfate
| OtherCompounds =
}}
}}
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.William Bauer, Jr. "Methacrylic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a16_441}}.
It can also be obtained by hydrolysis of sulfamic acid in aqueous solution, which produces the salt in high purity:
:{{chem2 | H3NSO3 + H2O -> (NH4)HSO4 }}
It also arises by the thermal decomposition of ammonium sulfate:
:{{chem2 | (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.{{Cite web|url=https://www.mindat.org/min-2382.html|title=Letovicite}}{{Cite web|url=https://www.ima-mineralogy.org/Minlist.htm|title=List of Minerals|date=21 March 2011}}