Chlorous acid

Chlorous acid
Names
	IUPAC name Chlorous acid, Chloric (III) acid
Identifiers
CAS Number	13898-47-0 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:29219 ;
ChemSpider	22861 ;
KEGG	C01486 ;
PubChem CID	24453;
UNII	7JRT833T5M ;
CompTox Dashboard (EPA)	DTXSID80160853 ;
	InChI InChI=1S/ClHO2/c2-1-3/h(H,2,3) Key: QBWCMBCROVPCKQ-UHFFFAOYSA-N ; InChI=1/ClHO2/c2-1-3/h(H,2,3) Key: QBWCMBCROVPCKQ-UHFFFAOYAO;
	SMILES O[Cl+] [O-];
Properties
Chemical formula	H Cl O2
Molar mass	68.46 g/mol
Acidity (pKa)	1.96
Conjugate base	Chlorite
	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

Chlorous acid is an inorganic compound with the formula HClO₂. It is a weak acid. Chlorine has oxidation state +3 in this acid. The pure substance is unstable, disproportionating to hypochlorous acid (Cl oxidation state +1) and chloric acid (Cl oxidation state +5):

2 HClO₂ → HClO + HClO₃

Although the acid is difficult to obtain in pure substance, the conjugate base, chlorite, derived from this acid is stable. One example of a salt of this anion is the well-known sodium chlorite. This and related salts are sometimes used in the production of chlorine dioxide.