Chlorous acid has the formula HClO2. It is a weak
acid. The chlorine atom possesses oxidation state ＋3 in
this acid. The pure substance is unstable and disproportionates to hypochlorous acid (Cl oxidation
state ＋1) and chloric acid (chlorine 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,
ClO2.
