Sodium tetrathionate

Sodium tetrathionate dihydrate

Names
IUPAC name Sodium (sulfonatodisulfanyl)sulfonate dihydrate
Identifiers
CAS Number	13721-29-4
Jmol 3D model	Interactive image
PubChem	203055
InChI InChI=1S/2Na.H2O6S4.2H2O/c;;1-9(2,3)7-8-10(4,5)6;;/h;;(H,1,2,3)(H,4,5,6);2*1H2/q2*+1;;;/p-2 Key: HAEPBEMBOAIUPN-UHFFFAOYSA-L
SMILES O.O.[O-]S(=O)(=O)SSS(=O)(=O)[O-].[Na+].[Na+]
Properties
Chemical formula	Na2S4O6
Molar mass	306.2665 g/mol (dihydrate)
Appearance	white powder
Density	2.1 g/mL (25 ℃)
Solubility in water	30.6 g/L (20 ℃)
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium tetrathionate is a salt of sodium and tetrathionate with the molecular formula Na₂S₄O₆. The structure of sodium tetrathionate is somewhat like two sodium thiosulfate (Na₂S₂O₃) molecules joined together at the S⁺² ends.

Sodium tetrathionate is formed by the oxidation of sodium thiosulfate (Na₂S₂O₃) with liquid iodine (I₂). The sodium tetrathionate Na₂S₄O₆ formed can be isolated from the solution by fractional crystallization.