What is "hypochlorous acid"

Hypochlorous \Hy`po*chlo"rous\, a. [Pref. hypo- + chlorous.] (Chem.) Pertaining to, or derived from, chlorine having a valence lower than in chlorous compounds.

Hypochlorous acid (Chem.), an acid derived from chlorine, not known in a pure state, but forming various salts, called hypochlorites.

n. (context chemistry English) a weak, unstable acid, HOCl, known only in solution; it is made by the action of chlorine on water and, along with its salts, the hypochlorites, is used as a household bleach

n. a weak unstable acid known only in solution and in its salts; used as a bleaching agent and as an oxidizing agent

Hypochlorous acid is a weak acid with the chemical formula HOCl. It forms when chlorine dissolves in water, and itself partially dissociates in water, into hypochlorite (-) and hydronium ions. It is HOCl and OCl- that are the primary agents for disinfection when chlorine is used to disinfect water for human use. It cannot be isolated in pure form due to rapid equilibration with its precursor. HClO is an oxidizer, and in its sodium salt form sodium hypochlorite (NaClO), or in its calcium salt form calcium hypochlorite (Ca(ClO)), can be used as a bleach, a deodorant, and a disinfectant.