REACTIONS OF CHLORINE DIOXIDE AND OTHER OXY-CHLORO COMPOUNDS WITH ORGANIC COMPOUNDS. KINETICS AND MECHANISMS OF THE REACTION BETWEEN CHLORITE AND HYPOCHLOROUS ACID IN AQUEOUS SOLUTION

The reaction of the formation of chlorine dioxide from hypochlorous acid and chlorite in aqueous solutions, which was studied in the present research is gHOCl + hClO2(-) yields pCl0w + qCl03(-) + rCl(-). Since chlorine dioxide, chlorite and hypochlorous acid have different absorption peaks in the ultra-violet range, the spectrophotometer was used as the method of analysis. Kinetic analysis of the concentration values of hypochlorous acid, chlorine dioxide and chlorite changing with time during the course of the reaction reveals that the rate of the overall reaction is first order with respect to the two reactants under the range of experimental conditions used. The yield of chlorine dioxide from chlorite varied from 35 to 65% within the experimental conditions described. It was observed that the majority of the chlorite consumed was oxidized to chlorine dioxide or chlorate whereas the hypochlorous acid consumed was reduced to chloride. A mechanism is suggested in which Cl2O2 is the activated intermediate complex. This mechanism suggests that the formation of the intermediate is the slow rate determining step.