Brief Overview
Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent sulfur odor. The main use for the chemical is as an antioxidant or chemical sterilant. It is a disulfite and is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite is generally preferred out of the two as it does not contribute sodium to the diet. Potassium metabisulfite has a monoclinic crystal structure which decomposes at 190°C, yielding potassium sulfite and sulfur dioxide:
K2S2O5(s) → K2SO3(s) + SO2(g)
Manufacturing Process
Potassium metabisulfite can be prepared by evaporating a solution of potassium bisulfite, saturated with sulfur dioxide:
2 KHSO3 ⇌ H2O + K2S2O5
Brief Overview
Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent sulfur odor. The main use for the chemical is as an antioxidant or chemical sterilant. It is a disulfite and is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite is generally preferred out of the two as it does not contribute sodium to the diet. Potassium metabisulfite has a monoclinic crystal structure which decomposes at 190°C, yielding potassium sulfite and sulfur dioxide:
K2S2O5(s) → K2SO3(s) + SO2(g)
Manufacturing Process
Potassium metabisulfite can be prepared by evaporating a solution of potassium bisulfite, saturated with sulfur dioxide:
2 KHSO3 ⇌ H2O + K2S2O5