General Studies I
Chlorination is a process used for water purification.
The disinfecting action of chlorine is mainly due to
|A||The formation of hydrochloric acid when chlorine is added to water|
|B||The formation of hypochlorous acid when chlorine is added to water|
|C||The formation of nascent oxygen when chlorine is added to water|
|D||The formation of hydrogen when chlorine is added to water|
Depending on the pH, hypochlorous acid partly dissociates to hydrogen and hypochlorite ions:
The disinfecting action of chlorine is mainly due to the hypochlorous acid, and to a small extent due to the hypochlorite ions. The hypochlorous acid is the most effective form of chlorine for water disinfection. It is more effective (70-80 times) than the hypochlorite ion. Chlorine acts best as a disinfectant when the pH of water is around 7 because of the predominace of hypochlorous acid.