When chlorine reacts with water, what disinfectant is formed?

When chlorine reacts with water, it primarily forms hypochlorous acid, a highly effective disinfectant used in pools to kill bacteria and other pathogens. The chemical reaction can be represented as chlorine (Cl2) dissolving in water (H2O) to produce hypochlorous acid (HOCl). This compound is particularly important for maintaining water quality in swimming pools because it acts as a powerful sanitizer, helping to ensure that the water remains safe for swimming and free from harmful microorganisms.

The formation of sodium chloride and calcium chloride does occur under specific conditions but isn't a direct result of this reaction with chlorine and water. Sodium chloride, for instance, is usually associated with the electrolysis of saltwater, while calcium chloride is a separate compound introduced for managing calcium levels in the pool water. Therefore, while those substances may be present in a pool environment, they do not result directly from the initial reaction between chlorine and water.