Potassium bisulfite (or potassium hydrogen sulfite) is a

chemical A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., w ...

mixture with the approximate

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

KHSO₃. Potassium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of potassium ions and bisulfite ions. It is a white solid with an odor of sulfur dioxide. Attempts to crystallize potassium bisulfite yield

potassium metabisulfite Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabi ...

, K₂S₂O₅. Potassium bisulfite is used as a sterilising agent in the production of alcoholic beverages. This additive is classified as E number E228 under the current EU-approved food additive legislation.

Production

It is made by the reaction of sulfur dioxide and

potassium carbonate Potassium carbonate is the inorganic compound with the formula K2 CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and gl ...

. The sulfur dioxide is passed through a solution of the potassium carbonate until no more carbon dioxide is evolved. The solution is concentrated.

References

Potassium compounds Bisulfites Food additives E-number additives {{inorganic-compound-stub

Production

See also

References