Difference between anhydrous sodium sulfite and anhydrous sodium sulfate

Chemical Properties

Sodium sulfite anhydrous is a strong reducing agent, easily soluble in water, aqueous solution is alkaline, slightly soluble in alcohol, insoluble in liquid chlorine and ammonia. It is easily oxidized to sodium sulfate in air, and decomposes to sodium sulfide and sodium sulfate when exposed to high temperature. In contrast, anhydrous sodium sulfate is a more stable compound, not easily reduced or oxidized.

sodium sulfite anhydrous (chemistry)

Differences in appearance

Sodium sulfate anhydrous is white uniform fine particles or powder. It is odorless and has a salty and bitter taste. Sodium sulfite anhydrous is soluble in water, the aqueous solution becomes alkaline, and is easily oxidized to sodium sulfate in the air.

Differences in application

Sodium sulfate anhydrous is used as filler for dyestuffs and auxiliaries in order to adjust the concentration of dyestuffs and auxiliaries so that they can reach the standard concentration. It can also be used as a dyeing promoter for direct dyes, sulfide dyes and reduction dyes in dyeing cotton fabrics, as a retarding agent for direct acid dyes in dyeing silk and wool animal fibers, and as a base color protection agent in refining printed silk fabrics.

Anhydrous sodium sulfite is easily oxidized into sodium sulfate in the air, and decomposed into sodium sulfide at high temperature. It can be used to strengthen the reducing agent, generate sodium bisulfite with sulfur dioxide, and react with strong acid to generate the corresponding salt, which is used for film development.

In general, although the names of anhydrous sodium sulfite and anhydrous sodium sulfate are similar, there are obvious differences in their chemical and physical properties as well as application areas. In practical applications, it is necessary to select the appropriate compound according to the specific chemical reaction and treatment requirements.