Atomic resonance fluorescence for rate constants of rapid bimolecular reactions. Part 5—Hydrogen atom reactions; H + NO2 and H + O3

Abstract

Direct determinations of the rate constants k₁ and k₂(cm³ molecule^–1 s^–1) are reported, for the reactions of H ²S atoms with NO₂ and O₃, using atomic resonance fluorescence in a discharge–flow system to detect hydrogen atoms. Measurements of k₁ for reaction (1) at four temperatures from 298 to 653 K were made: H + NO₂[graphic omitted] NO + OH; (1) the following overall Arrhenius expression was obtained: log₁₀k₁=(–9.319 ± 0.084)–(174 ± 31)/T(2σ). Measurements of k₂ for reaction (2) were made at three temperatures between 298 and 638 K: H + O₃[graphic omitted] O₂+ OH.(2) These results gave the expression: log₁₀k₂=(–10.005 ± 0.102)–(224 ± 26)/T(2σ).