Sodium dithionite

"Sodium hydrosulfite" redirects here. For sodium hydrogen sulfite (NaHSO3), sometimes erroneously referred to as sodium hydrosulfite, see Sodium bisulfite.
Not to be confused with Sodium hydrosulfide or Sodium dithionate.
Sodium dithionite
Sodium dithionite
Names
Other names
D-Ox, Hydrolin, Reductone
sodium hydrosulfite, sodium sulfoxylate, Sulfoxylate
Vatrolite, Virtex L
Hydrosulfit, Prayon
Blankit, Albite A, Konite
Zepar, Burmol, Arostit
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.028.991 Edit this at Wikidata
EC Number
  • 231-890-0
RTECS number
  • JP2100000
UNII
UN number 1384
  • InChI=1S/2Na.H2O4S2/c;;1-5(2)6(3)4/h;;(H,1,2)(H,3,4)/q2*+1;/p-2
    Key: JVBXVOWTABLYPX-UHFFFAOYSA-L
  • [O-]S(=O)S(=O)[O-].[Na+].[Na+]
Properties
Na2S2O4
Molar mass 174.107 g/mol (anhydrous)
210.146 g/mol (dihydrate)
Appearance white to grayish crystalline powder
light-lemon colored flakes
Odor faint sulfur odor
Density 2.38 g/cm3 (anhydrous)
1.58 g/cm3 (dihydrate)
Melting point 52 °C (126 °F; 325 K)
Boiling point Decomposes
18.2 g/100 mL (anhydrous, 20 °C)
21.9 g/100 mL (Dihydrate, 20 °C)
Solubility slightly soluble in alcohol
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H251, H302
P235+P410, P264, P270, P280, P301+P312, P330, P407, P413, P420, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
3
1
Flash point 100 °C (212 °F; 373 K)
200 °C (392 °F; 473 K)
Related compounds
Other anions
 Sodium sulfite
Sodium sulfate
Related compounds
 Sodium thiosulfate
Sodium bisulfite
Sodium metabisulfite
Sodium bisulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium dithionite (also known as sodium hydrosulfite) is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions.