Sodium Sulphite

Origin: China
CAS Number: 7757-83-7
HS Code: 2830.10.00

IUPAC Name: disodium sulfite
Molecular Formula: Na2SO3
Molecular Weight (g/mol): 126.0400
Synonyms & Trade Names: Sodium sulphite; Sodium sulfite anhydrous; E221
Purity / Assay (%): 97% min
Physical Form: Solid

Concentration: Pure substance
Appearance / Color: White to off-white solid
Odor: Sulfur-like, slight
Density (g/cm³): 2.6330
Solubility in Water: Freely soluble (28.3g/100mL)
Signal Word: Warning
GHS Hazard Class: Eye irritant; Skin sensitizer
H-Statements: H315|H317|H319
P-Statements: P261|P264|P272|P280|P305+P351+P338
REACH Status: Registered
Drug Precursor Status: Non-precursor
Storage Class (GHS): 10
Storage Conditions: Cool, dry; sealed; away from acids

Technical Document

Brief Overview
Sodium sulphite is widely used as a food preservative to prevent fresh produce and meat from discolouring. It is used in flue-gas desulfurization process. It is widely used in paper and pulp industry as an agent to avoid corrosion problems. A solution of sodium sulphite is of pH 9 and when the solution is exposed to air they are oxidised to sodium sulphate.
Manufacturing Process
Sulphur dioxide and sodium hydroxide when reacted together under laboratory conditions, produce sodium sulphite.
2NaOH + SO2 → Na2SO3 + H2O
In industrial level, sodium sulphite is produced by making sodium carbonate react with sulphur dioxide.
SO2 + Na2CO3 → Na2SO3 + CO2