6. [30] Dissolved chlorine rapidly hydrolyzes in water to form hypochlorous acid. In turn, hypoclorous acid dissociates in water to form OCl, a much less effective disinfectant. a) What percentage of added chlorine would be in the form of the most active oxidizer (HOCl) at pH6.5 ? At pH7.5 ? b) Given that an HOCl concentration of 0.03mM has been shown to result in a 95 percent kill in 10 minutes, how much time would be required for 98 percent kill with a total chlorine dose of 0.5mM at a pH of 6.5 ? At a pH 7.5? (Hint: Assume that the water contains only cells and the added chlorine, and that only HOCl is an effective disinfectant.) c) What pereent kill would be achieved with a 20-minute exposure time at the does and at the two values of pH given in part (b)