Disodium hydrogen phosphite

Disodium hydrogen phosphite

Names
IUPAC name sodium phosphonate pentahydrate
Other names Sodium phosphite dibasic pentahydrate, sodium phosphite
Identifiers
CAS Number	13708-85-5 13517-23-2 (pentahydrate)
3D model (Jmol)	Interactive image Interactive image
ChemSpider	21106436
ECHA InfoCard	100.033.848
InChI InChI=1S/2Na.O3P/c;;1-4(2)3/q2*+1;-3/p+1 Key: XWGAABYWOLJBFF-UHFFFAOYSA-O InChI=1/2Na.O3P/c;;1-4(2)3/q2*+1;-3/p+1 Key: XWGAABYWOLJBFF-IKLDFBCSAK
SMILES O=P([O-])([O-])[H].[Na+].[Na+] [H+].[Na+].[Na+].[O-]P([O-])[O-]
Properties
Chemical formula	HNa2O3P
Molar mass	125.96 g·mol^−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Disodium hydrogen phosphite is the chemical compound Na₂HPO₃ which is commonly encountered as the pentahydrate. It is a salt of phosphorous acid, HP(O)(OH)₂ and contains the anion HPO₃²⁻. Its common name suggests that it contains an acidic hydrogen atom, as in sodium hydrogen carbonate. However, this is misleading as the hydrogen atom is bonded to phosphorus rather than oxygen. It is toxic along with all phosphites. Phosphites contain phosphorus in its +3 oxidation state and are therefore reducing agents.