Sodium thiosulfate

Sodium thiosulfate
Sodium thiosulfate
Names
IUPAC name
Sodium thiosulfate
Other names
Sodium hyposulphite
Hyposulphite of soda
Hypo
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.028.970 Edit this at Wikidata
EC Number
  • anhydrous: 231-867-5
E number E539 (acidity regulators, ...)
RTECS number
  • anhydrous: XN6476000
UNII
  • InChI=1S/2Na.H2O3S2/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 checkY
    Key: AKHNMLFCWUSKQB-UHFFFAOYSA-L checkY
  • anhydrous: InChI=1/2Na.H2O3S2/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2
    Key: AKHNMLFCWUSKQB-NUQVWONBAM
  • pentahydrate: InChI=1S/2Na.H2O3S2.5H2O/c;;1-5(2,3)4;;;;;/h;;(H2,1,2,3,4);5*1H2/q2*+1;;;;;;/p-2
    Key: PODWXQQNRWNDGD-UHFFFAOYSA-L
  • anhydrous: [Na+].[Na+].[O-]S(=O)(=O)[S-]
  • pentahydrate: O.O.O.O.O.[Na+].[Na+].[O-]S(=O)(=O)[S-]
Properties
Na2S2O3
Molar mass 158.11 g/mol (anhydrous)
248.18 g/mol (pentahydrate)
Appearance White crystals
Odor Odorless
Density 1.667 g/cm3
Melting point 48.3 °C (118.9 °F; 321.4 K) (pentahydrate)
Boiling point 100 °C (212 °F; 373 K) (pentahydrate, - 5H2O decomposition)
70.1 g/100 mL (20 °C)[1]
231 g/100 mL (100 °C)
Solubility negligible in alcohol
1.489
Structure
monoclinic
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Flash point Non-flammable
Safety data sheet (SDS) External MSDS
Related compounds
Other cations
 Thiosulfuric acid
Lithium thiosulfate
Potassium thiosulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Sodium thiosulfate (sodium thiosulphate) is an inorganic compound with the formula Na2S2O3·(H2O)x. Typically it is available as the white or colorless 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.[2]

  1. ^ Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. ^ Barbera JJ, Metzger A, Wolf M (2012). "Sulfites, Thiosulfates, and Dithionites". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a25_477. ISBN 978-3-527-30673-2.