Sodium Sulfite

Molecular formula：NaSO3

Molecular weight：126.04(252.04)

Appearance and Character：White, monoclinic crystal or powder.

Product overview:Sodium sulfite (anhydrous), common sulfite, colorless, monoclinic crystal or powder. It can irritate eyes, skin and mucosa and pollute water sources. Toxic sulfide fumes are produced by high thermal decomposition. In industry, it is mainly used to produce cellulose sulfite, sodium thiosulfate, organic chemicals, bleached fabrics, etc. It is also used as reducing agent, preservative, dechlorinating agent, etc.

Chemical properties:Sodium sulfite is easily weathered in air and oxidized to sodium sulfate. The crystalline water is lost at 150 ℃. Reheating melts into a mixture of sodium sulfide and sodium sulfate. The density of anhydrous matter is 2.633. It oxidizes much slower than hydrate and remains unchanged in dry air. Sodium sulfide and sodium sulfate are produced by thermal decomposition, and sulfur dioxide is released by decomposition into corresponding salts in contact with strong acids. Sodium sulfite has strong reducibility. It can reduce copper ions to cuprous ions (sulfite can form complex with cuprous ions and is stable), and it can also reduce weak oxidants such as phosphotungstic acid. Sodium sulfite and its hydrogen salts can be used in the laboratory to remove peroxides of ether substances (adding a small amount of water, slightly heat stirring reaction, then separating the liquid, drying the ether layer with quicklime, for some less demanding reactions). It can be neutralized with hydrogen sulfide.

Main uses:

1. Used for the determination of tellurium and niobium in trace analysis and the preparation of developer solution, and as reducing agent.

2. Used in artificial fibre stabilizer, fabric bleaching agent, photographic developer, dyeing and bleaching deoxidizer, perfume and dye reductant, paper lignin remover, etc.

3. Used as general analytical reagent and photoresistor material

4. Reductive bleaching agent has bleaching effect on food and strong inhibitory effect on oxidase in vegetable food. Our country stipulates that it can be used for candied fruit with a maximum usage of 2.0g/kg. It can also be used for concentrated juice of glucose, liquid glucose, sugar, ice sugar, bait sugar, candy, bamboo shoots, mushrooms and canned mushrooms, grapes, blackcurrants, etc.

5. Printing and dyeing industry, as deoxidizer and bleaching agent, is used in the boiling of various cotton fabrics, which can prevent the local oxidation of cotton fabrics and affect the strength of the fibers, and improve the whiteness of the boiled products. The photosensitive industry is used as a developer. Organic industry is used as reductant in the production of m-phenylenediamine, 2,5-dichloropyrazolone, anthraquinone-1-sulfonic acid, 1-aminoanthraquinone, sodium aminosalicylate and so on, which can prevent the oxidation of semi-finished products in the reaction process. The paper industry is used as lignin remover. The textile industry is used as a stabilizer for man-made fibers. The electronics industry is used to make photoresistors. Water treatment industry is used to treat electroplating wastewater and drinking water.

6. Food industry is used as bleaching agent, preservative, loosening agent and antioxidant. It is also used in pharmaceutical synthesis. Used as a reducing agent in the production of dehydrated vegetables.

7. It is used to produce cellulose sulfite, sodium thiosulfate, organic chemicals, bleached fabrics and so on. It is also used as reducing agent, preservative and dechlorinating agent.