Chlorous
Chlorous refers to a chemical state or compound containing chlorine in a specific oxidation state. It is most commonly associated with chlorous acid and its salts, known as chlorites. In these compounds, chlorine has an oxidation state of +3. Chlorous acid, HClO2, is a weak acid. It is unstable and disproportionates readily into hydrochloric acid and chloric acid, or further into perchloric acid. This instability means chlorous acid is not typically isolated or used directly.
Chlorites, the salts of chlorous acid, are more stable and are the practical compounds encountered. Sodium chlorite