Sodium Thiosulfate Pentahydrate [Na2O3S2.5H2O] [CAS_10102-17-7] Photo Grade 99+%, Monoclinic Crystal (50 Lb Bag)

$ 154.00 $ 182.00

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


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%


50 lb paper bag

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