Overview

Sodium sulfite (SO-dee-um SUL-fite) is a white powder or crystalline solid with no odor but a slightly salty taste. The compound is stable in dry air, but tends to decompose in moist air to produce sulfur dioxide (SO₂) and sodium hydroxide (NaOH). The compound has a variety of uses as a food preservative and in the paper and pulp industry.

How It Is Made

Sodium sulfite can be prepared by reacting sulfur dioxide, soda ash (sodium carbonate; Na₂CO₃), and water. The product of this reaction is sodium bisulfite (NaHSO₃), which is then treated with excess soda ash to obtain sodium sulfite. The compound can also be obtained as a byproduct in the preparation of phenol (C₆H₅OH).

Key Facts

Other Names:

Disodium sulfite

Formula:

Na₂SO₃

Elements:

Sodium, sulfur, oxygen

Compound Type:

Salt (inorganic)

State:

Solid

Molecular Weight:

126.04 g/mol

Melting Point:

Not...