Chemical Name: Sodium Thiosulfate
Chemical Synonyms: Sodium Hyposulfite; Hypo; Disodium Thiosulfate
CAS No.: 7772-98-7
Molecular Formula: Na₂O₃S₂ (Na₂S₂O₃)
Molecular Weight: 158.11 g/mol
Sodium Thiosulfate (CAS 7772-98-7), also known as Sodium Hyposulfite or Hypo, is an inorganic reducing agent widely used in photographic processing, water treatment, and industrial applications. This grade is anhydrous (Na₂S₂O₃, MW 158.11), distinguishing it from the more common pentahydrate form. It serves as an effective chlorine neutralizer, photographic fixer, and analytical reagent. With assay ≥99% and compliance with industrial standards, it is suitable for photography, water dechlorination, and chemical synthesis.
Parameter | Specification |
|---|---|
Product Name | Sodium Thiosulfate (Anhydrous) |
Synonyms | Sodium Hyposulfite; Hypo; Disodium Thiosulfate |
CAS Number | 7772-98-7 |
Molecular Formula | Na₂O₃S₂ (Na₂S₂O₃) |
Molecular Weight | 158.11 g/mol |
EINECS No. | 231-867-5 |
Assay / Purity | ≥99% |
Appearance | White crystalline powder or colorless crystals |
pH (5% solution) | 6.0–8.5 |
Solubility | Freely soluble in water; insoluble in ethanol |
Grade | Industrial Grade / Photo Grade |
Storage | Cool, dry place, sealed and protected from light and moisture |
Photographic Processing: Standard photographic fixer for film and paper processing, dissolving silver halides .
Water Treatment: Dechlorination agent for tap water, aquariums, swimming pools, and spas .
Analytical Chemistry: Reducing agent for iodometric titrations and volumetric analysis .
Industrial Bleaching: Antichlor after bleaching of cotton fabrics, pulp, and paper .
Gold Extraction: Used in gold leaching and recovery processes .
Anhydrous Form: Higher active content per unit weight compared to pentahydrate, reducing shipping and storage costs per effective unit.
High Purity: Assay ≥99% suitable for photographic and analytical applications requiring consistent reducing power.
Stable Supply: Reliable production capacity supporting both sample trials and bulk orders.
Full Documentation: COA and MSDS available upon request.
Standard Packaging: 25 kg / 50 kg / 1000 kg in PP woven bags or fiber drums, or customized packaging upon request .
Storage Conditions: Store in a tightly closed container in a cool, dry place, protected from light and moisture. Avoid contact with strong acids and oxidizing agents.
Shelf Life: 12–24 months under proper storage conditions.