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): Although the acid is difficult to obtain in pure substance, the conjugate base, chl... Found on http://en.wikipedia.org/wiki/Chlorous_acid