Sodium Sulfite

Property: white gravel or powder crystal,relative density is 1.561, less to dissolve in water and its water solution has alkaline reaction; it is hard to dissolve in ethanol. It is used to produce chloroform,solasulfone and Benzaldehyde in medical industry.

Molecular Formula : Na₂SO₃

Molecule Weight : 126.04

CAS NO .: 7757-83-7

Appearance : White Free Flowing Fine Crystal or Powder

Specification for Industry Grade and Food Grade :

Item	Quality Index
Item	Industry Grade	Food Grade
Purity ( As Na₂SO₃)	96.0% min	98.0% min
Sodium sulphate ( SO₄)	2.5% max	1.5% max
Chlorides ( As NaCL)	0.5% max	0.1% max
Arsenic ( As )	-	0.0002% max
Heavy metals ( As Pb )	-	0.0005% max
Iron (Fe)	0.005% max	0.002% max
Water insolubles	0.05% max	0.02% max

Specification For Photo Grade and Pharmaceutical Grade

Item	Quality Index
Item	Photo Grade	Pharmaceutical Grade
Purity ( As Na₂SO₃)	98.0% min	98.0% min
Sodium sulphate ( SO₄ )	1.5% max	1.5% max
Chlorides ( As CL^-)	0.05% max	0.05% max
Arsenic ( As )	0.0002% max	2ppm max
Lead ( As Pb)	0.0005% max	2ppm max
Iron (Fe)	0.001% max	5ppm max
Selenium ( Se)	0.0001% max	1ppm max
Zinc ( Zn)	0.0001% max

Properties

Sodium sulfite is an inorganic compound. It is a white granular powder at room temperature, soluble in water and reducing. It is disproportioned into sodium sulfide and sodium sulfate when heated and gradually oxidized into sodium sulfate when placed in air. It can exist in three forms: anhydrous matter, heptahydrate and decahydrate, of which anhydrous matter is the most difficult to be oxidized. Its aqueous solution is alkaline due to hydrolysis and releases toxic sulfur dioxide gas during acidification. Sodium sulfite can be prepared by introducing sulfur dioxide into sodium hydroxide solution. When sulfur dioxide is excessive, sodium bisulfite will be generated. Sodium sulfite can be used as developer, preservative of dried fruit and meat, Deoxidizer in printing and dyeing industry, and reducing chemical reagent. It is used in chemical industry and laboratory production and synthesis.

CAS No.

7757-83-7

Formula

Na2O3S

Molecular Mass

126.04300

Exact Mass

125.93600

PSA

82.40000

Logp

-0.13840