Phosphite (ion)

Phosphite (ion)
Names
	IUPAC name Phosphonate
	Systematic IUPAC name Phosphite
Identifiers
CAS Number	15477-76-6 ;
3D model (JSmol)	hypervalent form: Interactive image; ionic form: Interactive image;
ChEBI	CHEBI:16215 ;
ChemSpider	10449627 ;
Gmelin Reference	1618
MeSH	Phosphorite
PubChem CID	406;
CompTox Dashboard (EPA)	DTXSID80164154 ;
	InChI InChI=1S/O3P/c1-4(2)3/q-3 Key: AQSJGOWTSHOLKH-UHFFFAOYSA-N ;
	SMILES hypervalent form: P([O-])([O-])=O; ionic form: [H][P+]([O-])([O-])[O-];
Properties
Chemical formula	HPO2−; 3
Molar mass	79.9810 g mol−1
Related compounds
Other anions	Phosphinite; Phosphonite
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

A phosphite ion in inorganic chemistry usually refers to [HPO₃]²⁻ but includes [H₂PO₃]⁻ ([HPO₂(OH)]⁻). These anions are the conjugate bases of phosphorous acid (H₃PO₃). The corresponding salts, e.g. sodium phosphite (Na₂HPO₃) are reducing in character.