Chlorous acid is an inorganic compound with the chemical formula HClO2. It is a weak acid. The oxidation state of chlorine in this acid is +3. The pure product is unstable and disproportionated into hypochlorous acid (Cl oxidation state +1) and chloric acid (Cl oxidation state +5)
Although this acid is difficult to obtain in pure form, the conjugate base chlorite derived from this acid is stable. An example of such an anionic salt is the well known sodium chlorite. This and related salts are sometimes used in the production of chlorine dioxide.
Chlorous acid is a strong oxidizing agent, although its tendency to disproportionate counteracts its oxidative potential.

Chlorine is the only halogen that forms a separable acid of the formula HXO2. [1] Neither bromic acid nor iodic acid was isolated. Some bromates, bromites, are known, but not iodates
Halous acid and rock salt
Chlorous acid is the most unstable of all oxyacids. It can be prepared by treating a suspension of barium chlorite with sulfuric acid and then removing the precipitated barium sulfate:

HClO2 exists only in aqueous solution. It decomposes rapidly in alkali to generate chlorite and chlorate ions, and rapidly decomposes in acid to generate chlorine dioxide, chlorate ions and chloride ions. There is some circumstantial evidence for bromic and iodic acids, but they are not even as stable as HCIO2.
Write the appropriate Lewis electronic point formula for (a) the chlorate ion, ClO3?; (b) chlorous acid, HClO2; (c) the nitrosyl ion, NO+.
The arrangement of atoms in ClO3? is
Peroxide is the preferred reducing agent because it adds no contaminant to the resulting chlorite solution. Heavy metal chlorites tend to explode when heated or subjected to pressure. Chlorite salts of Groups 1 and 2 are more stable, but NaClO2 is the only one that is of any commercial importance.

Neutral or basic solutions of NaClO2 disproportionate so slowly at room temperature that they are considered stable. Heating or exposure to light speeds up the rate of reaction, and the solutions gradually decompose to chloride and chlorate ions. The main uses of NaClO2 are in bleaching and removal of pollutants from industrial off-gases.