Kinetics of the reaction of OH with ClO

Abstract

The kinetics of the reaction of OH with ClO [graphic omitted], have been investigated over the temperature range 243–298 K using a discharge-flow system. The system was equipped to determine [OH] and [Cl] by resonance fluorescence; [HO₂] and [ClO] could be measured indirectly, after chemical conversion. Measurement of concentrations of both reactants, as well as the HO₂ product of reaction (1), permitted k₁(=k_1a+k_1b) and the branching ratio, α(=k_1a/k₁), to be determined as a function of temperature. Both k₁ and α were found to be independent of temperature over the range studied, with average values of k₁= 11.9 ± 0.9 × 10^–12 cm³ molecule^–1 s^–1 and α= 0.85 ± 0.07. (Errors are 95% confidence limits for random errors; systematic errors to contribute up to a further 20% range.) The implications of the results for terrestrial atmospheric chemistry are discussed.