Sodium Tiosulphate

Synonyms: sodium hyposulphite, sodium thiosulphate 5-hydrate

Chemical formula: Na2S2O3.5H2O

International name: SODIUM THIOSULFATE Pentahydrate

CAS No.: 10102-17-7

Grade: pure

Appearance: colorless crystals, granules

Sodium thiosulphate (sodium hyposulphite, sodium thiosulphate 5-hydrate) is non-caking colorless crystals, granules. Whitish, yellowish or light pink tints are acceptable. It is soluble in water (41.2% at 20°C, 69.86% at 80°C). Sodium thiosulphate is a strong reducer.

Production

Sodium thiosulphate (thiosulphate, hyposulphite, sodium thiosulphate) can be produced by means of a few methods, e.g.:

• Na polysulfide oxidation,
• boiling excess sulphur with Na2SO3,

· interaction of H2S and SO2 with NaOH, etc.

Pure anhydrous sodium thiosulphate can be produced by reaction of sulphur with sodium nitrate in formamide.

Application

Sodium thiosulphate (sodium hyposulfite) is widely used in various sectors of national economy:

• photo-movie picture industry,
• leather, pulp and paper, chemical industries,
• in comsumer industry for bleaching threads, for removing chloride traces upon fabric bleaching,
• for silver recovery from ores;
• as a reagent in iodometry,
• in pharmaceutical industry for production of antibiotics when preparing culture media,
• in treatment plants for purification from harmful impurities,
• in production of washing and cleaning agents,
• in food industry as a food additive E539, etc.