Potassium sulfite

Potassium sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water. Potassium sulfite is used for preserving food and beverages.

Production and reactions
Potassium sulfite is produced by the thermal decomposition of potassium metabisulfite at 190 °C:
 * K2S2O5 -> K2SO3 + SO2

Structure
The structure of solid K2SO3, as assessed by X-ray crystallography. The S-O distances are 1.515 Å, and the O-S-O angles are 105.2°