A study of the Br + IO → I + BrO and the reverse reaction

The rate coefficient, k1 (298 K) = (5.0 ± 1.1) × 10−11 cm3 molecule−1 s−1, for the reaction, Br + IO → I + BrO (1) was determined by monitoring the temporal profiles of IO in an excess of Br. The rate coefficient for the reverse reaction, I + BrO → IO + Br(−1), k−1 (298 K) = (1.9 ± 1.1) × 10−11 cm3 molecule−1 s−1, was determined by modeling IO temporal profiles, measured in the presence of BrO and O3, in which the regeneration of IO was observed. From these rate coefficients, the difference in the heats of formations of IO and BrO, ΔfH° (298 K) (BrO) − ΔfH° (298 K) (IO), was calculated to be 0.5 ± 0.6 kcal mol−1.