kaliumsulfiet

Kaliumsulfiet is the potassium salt of sulfurous acid with the chemical formula K2SO3. It is an inorganic compound that appears as a white crystalline solid. In aqueous solution, it is alkaline due to hydrolysis.

Kaliumsulfiet can be prepared by reacting potassium carbonate or potassium hydroxide with sulfur dioxide. It is soluble in water and insoluble in alcohol. It is a reducing agent, and its solutions can be oxidized by air to potassium sulfate.

Historically, kaliumsulfiet has found use as a food preservative, particularly in wine and dried fruits, to prevent oxidation and inhibit microbial growth. However, its use in food is now restricted or banned in many regions due to concerns about potential health effects and the availability of alternative preservatives. It can also act as a bleaching agent. In photography, it has been used as a fixing agent and a preservative for developing solutions. In chemical synthesis, it can be employed as a reducing agent.

When heated strongly, kaliumsulfiet decomposes. It is an irritant to the eyes and skin. Prolonged or repeated exposure may cause respiratory irritation.