| IUPAC name
Potassium hydrogen sulfite
| Other names
Sulfurous acid, monopotassium salt
|Molar mass||120.1561 g/mol|
|Appearance||White crystalline powder|
|Melting point||190 °C (374 °F; 463 K) (decomposes)|
| 49 g/100 mL (20 °C) |
115 g/100 mL (100 °C)
|Solubility||Insoluble in alcohols, benzene, toluene|
|Safety data sheet||CAMEO (solution)|
| Potassium sulfite|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Potassium bisulfite or potassium hydrogen sulfite is a chemical compound with the chemical formula KHSO3. The compound is commonly used in food industry, for sterilizing wine, as food additive E228. While it can be found as solid, it is more commonly encountered as solution.
Potassium bisulfite oxidizes in air to potassium bisulfate.
Addition of a base raises the pH, converting the compound in potassium sulfite.
Potassium bisulfite is a white solid, with a sulfurous smell, soluble in water.
Potassium bisulfite is sold as both solid and solution, with the latter being more available. Make sure to check the product label/designation, as some products labeled as potassium bisulfite are actually potassium metabisulfite.
It is available as the food additive E228.
- Reducing agent
- Make potassium bisulfate
Potassium bisulfite releases toxic sulfur dioxide gas. Work in a well ventilated area or fumehood.
Should be stored in closed, air-tight bottles.
Can be neutralized with bleach or hydrogen peroxide, then with a base to potassium sulfate.