Reactions of Cl₂ with Water

Usually, reactions of chlorine with water are for disinfection purposes. Chlorine is only slightly soluble in water, with its maximum solubility occurring at 49° F. After that, its solubility decreases until 212° F. At temperatures below that range, it forms crystalline hydrates (usually Cl₂) and becomes insoluble. Between that range, it usually forms hypochlorous acid (HOCl). This is the primary reaction used for water/wastewater disinfection and bleaching.

At the boiling temperature of water, chlorine decomposes water