Chlorous acid

Chlorous acid
IUPAC name	Chlorous acid
Identifiers
CAS number	[13898-47-0]
Properties
Molecular formula	HClO2
Molar mass	68.46 g/mol
Acidity (pKa)	1.96
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references

Chlorous acid is a chemical compound with the formula HClO₂. It is a weak acid. Chlorine possesses 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).

2HClO₂(aq) → HClO(aq) + HClO₃(aq)

Chlorite salts such as sodium chlorite are stable conjugate bases derived from this acid. These salts are sometimes used in the production of chlorine dioxide.

Preparation

HClO₂ can be prepared through reaction of barium chlorite and dilute sulfuric acid:

Ba(ClO₂)₂ + H₂SO₄ → BaSO₄ + 2HClO₂

Stability

Chlorine is the only one of the four halogens to form an isolable acid of formula HXO₂.^[1] Fluorine does not have the bonding capacity to do so, whereas the hypothetical bromous acid and iodous acid have never been isolated and only a few salts of bromous acid, bromites, are known, and no iodites.^[1]

References

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2007)

1. ^ ^{a b} Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN 0123526515

This inorganic compound-related article is a stub. You can help Wikipedia by expanding it.