Abstract
Bromide ion is rapidly converted to HOBr via BrCl by reaction with HOCl. The subsequent slow reactions of (HOCl, OCl−)/(HOBr, OBr−) mixtures are monitored directly by multiwavelength UV–vis absorbance methods and simultaneously by ion chromatographic measurement of ClO2−, ClO3−, and BrO3−
(p[H+] 5.6–7.6). A first-order loss of HOCl is observed which is catalyzed by trace concentrations of Br− and BrCl. Chlorite ion forms first and is subsequently oxidized to ClO3−. The loss of HOBr is slower and is second-order in HOBr, so that BrO3− formation takes longer than ClO3− formation. Under the conditions of this work, the relative yield of BrO3− increases with
increase in pH. The