Applications

• As a component in hand warmers and other chemical heating pads that produce heat by exothermic crystallization of a supercooled solution.
• In bleach
• In pH testing of bleach substances.
• To dechlorinate tap water for aquariums or treat effluent from waste water treatments prior to release into rivers. The reduction reaction is analogous to the iodine reduction reaction. Treatment of tap water requires between 0.1 grams and 0.3 grams of pentahydrated (crystalline) sodium thiosulfate per 10 liters of water.
• To lower chlorine levels in swimming pools and spas following super chlorination.
• To remove iodine stains, e.g. after the explosion of nitrogen triiodide.
• In bacteriological water assessment.
• In the tanning of leather.
• To demonstrate the concept of reaction rate in chemistry classes.
• To demonstrate the concept of supercooling in physics classes. Melted sodium thiosulfate is very easy to overcool to room temperature and when crystallization is forced, the sudden temperature jump to 48.3 deg C can be experienced by touch.
• As part of patina recipes for copper alloys.
• Often used in pharmaceutical preparations as an anionic surfactant to aid in dispersion.
• It can also be used as a very interesting solute in supersaturation experiments.
• As an ingredient to table salt
• Gold Extraction
• Antidote to cyanide poisoning
• Photographic processing

General

What is Sodium Thiosulphate? It is an inorganic compound with the formula Na₂S₂O₃·(H₂O)x. Typically it is available as the white or colourless pentahydrate (x = 5), which is a white solid that dissolves well in water. The compound is a reducing agent and a ligand, and these properties underpin its applications.

Consistent Quality: We provide only high-quality Sodium Thiosulphate Pentahydrate, ensuring reliable and consistent performance for all applications.

Shipped from Manchester, UK Facility: Sourced and packaged in non-toxic, chemical-resistant containers to ensure safe handling and preserve product quality during transport.

Frequent Uses

Water Treatment
It is used to dechlorinate tap water, remove excess chlorine from swimming pools after super-chlorination, and treat wastewater before discharge into the environment. 

Photography
Acts as a fixer, dissolving unexposed silver salts in photographic development. 

Gold Extraction
Used in the mining industry to extract gold by forming a soluble complex with gold ions.

Analytical Chemistry
Employed as an analytical reagent in laboratories.

Specification

• Minimum Assay: >99.0%
• Molecular Formula: Na2S2O3•5H₂O
• Molecular Weight: 241.17 g/mol
• Solubility in water (% weight): 79g/100 ml water @ 40 C
• Melting Point: 48 °C
• Calcium (Ca): <0.30%
• Iron (Fe): <10ppm
• Heavy Metals (as Pb): <10ppm
• Acidity: <0.01%
• Alkalinity: <0.06%

Hazards

Hazard Phrases: Not considered harmful under normal laboratory conditions