Reactions of atomic hydrogen and deuterium with Cl2 and Br2

Abstract

A discharge-flow, resonance absorption method has been used to determine the rate constants for the reactions of ground-state H and D atoms with Cl₂ and Br₂ at room temperature. Pseudo-first-order rate constants/cm³ molecule^–1 s^–1, 2σ, were obtained as a function of the reagent concentrations and yielded the following results at 295 K: H + Cl₂ [graphic omitted] HCl + Cl, k₁= 2.13(±0.78)×10^–11; D + Cl₂ [graphic omitted] DCl + Cl, k₂= 1.40(±0.44)×10^–11; H + Br₂ [graphic omitted] HBr + Br, k₃= 8.2(±3.8)×10^–11; D + Br₂ [graphic omitted] DBr + Br, k₄= 5.6 ±(0.9)×10^–11; The isotopic ratios, k₁/k₂= 1.5 and k₃/k₄= 1.5, are in the range expected for these reactions.