THE KINETICS OF THE BROMATE-SULFITE REACTION SYSTEM

The kinetics of the reaction between BrO3- and sulfite was studied by measuring the concentrations of [Br-] and [H+] both in buffered and in unbuffered solutions. A mechanism was applied for simulation of the e xperimental observations. Rate constants k(1) = (0.027 +/- 0.004) M(-1 )s(-1) and k(2) = (85 +/- 5) M(-1)s(-1) were determined for the follow ing reactions: 3 HSO3- + BrO3- --> 3 SO42- + Br- + 3 H+ (1) 3 H2SO3(or SO2 aq) + BrO3- --> 3 SO42- + Br- + 6 H+ (2) Rate constant k(1) was o btained directly from the experimental results on unbuffered reactions , where Reaction (1) was predominant. Rate constant k(2) was obtained by computer fitting of [Br-] to the experimental values for buffered r eactions, where the rate of Reaction (2) was about four times higher t han that of Reaction (1). (C) 1998 John Wiley & Sons, Inc.