Physical Properties Of Sodium Thiosulfate Pentahydrate
Oct 29, 2021
Properties: Colorless monoclinic crystals, odorless, with a cool and bitter taste.
Melting point 40~45℃
Relative density 1.729 (17℃)
Solubility: Easily soluble in water, and the aqueous solution is nearly neutral. Soluble in turpentine and ammonia. Insoluble in ethanol. Decomposes in acidic solution.
When heated to 100°C, 5 crystal waters are lost. It is easy to weather in dry air above 33℃, and it is deliquescent in moist air.
Sodium thiosulfate pentahydrate (Big Soda/Hybo) is a colorless and transparent crystal. It is a hydrate of sodium thiosulfate. It is easily soluble in water, and its aqueous solution is slightly alkaline. It weathers in dry air above 33℃ and loses crystal water. It is relatively stable in neutral and alkaline solutions, and decomposes rapidly in acidic solutions.
