Difference between revisions of "Sodium thiosulfate"
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Revision as of 09:43, 9 July 2016
| IUPAC name
| Systematic IUPAC name
|Molar mass|| 158.11 g/mol (anhydrous)|
248.18 g/mol (pentahydrate)
|Appearance||White crystalline solid|
|Melting point||48.3 °C (118.9 °F; 321.4 K) (pentahydrate)|
|Boiling point||100 °C (pentahydrate) 320 °C (608 °F; 593 K) (decomposes)|
| 70.1 g/100 mL (20 °C)|
231 g/100 mL (100 °C)
|Safety data sheet||MSDS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Sodium thiosulfate is an inorganic compound with the chemical formula Na2S2O3. The solid is an efflorescent.
Sodium thiosulfate reacts with acids, releasing sulfur, and sulfur dioxide fumes:
- Na2S2O3 + 2 HCl → 2 NaCl + S + SO2 + H2O
When heated to 300 °C, sodium thiosulfate decomposes to sodium sulfate and sodium polysulfide:
- 4 Na2S2O3 → 3 Na2SO4 + Na2S5
Sodium thiosulfate is an odorless white crystalline solid, soluble in water, but almost insoluble in alcohols.
Sodium thiosulfate is sometimes sold in pharmacies or pet stores.
Sodium sulfite can also be used instead of sodium hydroxide.
- Iodine clock reaction
- Neutralize bleach
- Remove iodine stains
- Cyanide poisoning antidote
- Gold extraction
- Supercooling demonstration
- Redox titrations
- Bunte salts synthesis
- Thioglycolic acid synthesis
Sodium thiosulfate may cause irritation on contact.
In closed containers.
Not always required, but bleach can be used.