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.
Preparation
HClO2 can be prepared through reaction of barium or lead chlorite and dilute sulfuric acid:
Ba(ClO2)2 + H2SO4 → BaSO4 + 2HClO2
Pb(ClO2)2 + H2SO4 → PbSO4 + 2HClO2
Stability
Chlorous acid is a powerful oxidizing agent, although its tendency to undergo disproportionation counteracts its oxidizing potential.[citation needed]
Chlorine is the only halogen to form an isolable acid of formula HXO2.[2]Fluorine is resistant to oxidation, having a −1 oxidation state even in hypofluorous acid, and is thus unable to form fluorous acid, or any higher oxoacids; despite the name, fluorite minerals are chemically fluoride compounds. Neither bromous acid nor iodous acid has ever been isolated. A few salts of bromous acid, bromites, are known, but no iodites.[2]
References
↑Rennie, Richard, ed. (2020). Dictionary of chemistry. Oxford quick reference (8ed.). Oxford, United Kingdom; New York, NY: Oxford University Press. ISBN978-0-19-884122-7.
12Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN0-12-352651-5
