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 (NaClO2) is a common example and is a strong oxidizing agent. It is used in various industrial applications, including bleaching textiles and paper, disinfecting water, and as a component in some dental products. Due to its oxidizing properties, chlorites require careful handling to avoid contact with combustible materials. The term "chlorous" itself simply denotes this specific valence of chlorine, distinguishing it from other chlorine-containing species like hypochlorous acid (chlorine oxidation state +1) or chloric acid (chlorine oxidation state +5).