RATE OF HYPOBROMITE FORMATION IN CHLORINATED SEAWATER

The factors affecting the rate of formation of hypobromite ion in chlorinated seawater have been investigated. Apart from the expected oxidation of bromide by HOCl, the rate constant of which was found to be k//H equals 1. 57 multiplied by 10**6 exp( minus 1. 62 multiplied by 10**3/T)mol** minus **1dm**3s** minus **1, the hypochlorite ion-pairs formed with the major cations were found to provide anotherr reaction pathway. The ratios k prime //m equals k//m/K//m mol** minus **2dm**6s** minus **1, where k//m is the rate constant and k//m the ion-pair formation constant, were as follows: CaOCl** plus , 1. 7 multiplied by 10**4; MgOCl** plus , 4. 2 multiplied by 10**3; NaOCl degree , 12; KOCl degree , 3 and these enabled the effect of the presence of the metal ions on the overall rate to be calculated. Transition metal ions at the low concentrations that could be tested had no catalytic effect but Fe**2** plus and Mn**2** plus ions were themselves oxidized.