What is the term for the chlorine left after breakpoint chlorination?

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Breakpoint chlorination happens when enough chlorine is added to oxidize all ammonia and other substances that would consume chlorine. After this point, the chlorine that's left in the water is the free chlorine residual, consisting of hypochlorous acid and hypochlorite ions that remain unbound. This free chlorine is the active disinfectant circulating in the system. If ammonia is still present, some chloramines can form and persist as combined chlorine, but the residual immediately after breakpoint is primarily free chlorine. Chloramine and disinfection byproducts relate to other aspects of chlorine chemistry, but the chlorine left after breakpoint is the free chlorine residual.