Product Description

Wintersun code: 19-125
CAS Number: 10102-17-7
Molecular Formula: Na2O3S2.5H2O
Molecular Weight: 248.18


Sodium Thiosulfate is a white translucent crystals or powder that is common as the pentahydrate form; melting at 48 C; readily soluble in water and oil of turpentine; aqueous solution is slightly alkaline which decompose to sulfate and sulfide in the air. It is a moderate reducing agent. It is a source of thiosulfate ion (S2O3-2) (dissolves silver salts). Its major use is as a fixing agent in photography for developing film and the extracting silver from ore. It is used in chrome-tanning leather and in chemical manufacture as a source of sulfide ion. It is also used in paper, textile, and water treatment industry and gas purification.

Sales Specification

Appearance: Monoclinic system crystal, colorless transparent
Sodium Thiosulfate (as Na2S2O3.5H2O) percent by mass, min: 99.00%
pH of 10% Solution: 6.0 to 8.0
Insoluble matter and metals other than alkali metals, percent by mass, max: 0.01%
Sodium Sulphide (as Na2S) percent by mass, max: 0.01% to 0.001%
Heavy Metals (as Pb) percent by mass, max: 0.003%
Iron (as Fe) percent by mass, max: 0.002%
Particle size: 10-12 MM


50lb paper bag, 44 bags per pallet