Potassium bisulfite

Potassium bisulfite

Names
IUPAC name Potassium hydrogen sulfite
Other names Potassium bisulfite, potassium bisulphite solution, sulfurous acid, monopotassium salt, monopotassium sulfite
Identifiers
CAS Number	7773-03-7 Y
3D model (Jmol)	Interactive image
ChemSpider	22889 N
ECHA InfoCard	100.028.973
EC Number	231-870-1
E number	E228 (preservatives)
PubChem	23663620
UNII	QJK5LO891P N
InChI InChI=1S/K.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+1;/p-1
SMILES OS(=O)[O-].[K+]
Properties
Chemical formula	KHSO3
Molar mass	120.1561 g/mol
Appearance	White crystalline powder
Odor	SO2
Melting point	190 °C (374 °F; 463 K) (decomposes)
Solubility in water	49 g/100 mL (20 °C) 115 g/100 mL (100 °C)
Solubility	insoluble in alcohol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Potassium hydrogen sulfite or potassium bisulfite is a chemical compound with the chemical formula KHSO₃. It is used during the production of alcoholic beverages as a sterilising agent. This additive is classified as E number E228 under the current EU approved food additive.

It is made by the reaction of sulfur dioxide and potassium carbonate. The sulfur dioxide is passed through a solution of the potassium carbonate until no more carbon dioxide is given off. The solution is concentrated and then allowed to crystallize.