Elsevier, Radiation Physics and Chemistry, (117), p. 7-11, 2015
DOI: 10.1016/j.radphyschem.2015.07.007
Full text: Unavailable
The temperature dependence of the rate constant for the reaction of dichloride anion radical (Cl2-∙) with atomic hydrogen (H∙) in water up to 75 °C has been determined by pulse radiolysis of deaerated 0.1 M HCl solution. The room temperature value is (6.1±0.6)×109 M-1 s-1. The activation energy of (13.2±0.6) kJ mol-1 is less than 16.7 kJ mol-1, expected for the diffusion-controlled reaction. Based on the temperature dependence of the rate constant for the reactions H∙+ Cl2-∙ and H∙+Cl2, derived in this work, and on that reported earlier (Szala-Bilnik et al., 2014) for Cl2-∙ + Cl2-∙, we show that a value of (10±2) M-1 s-1 determined by Hartig and Getoff (1982) for k (H∙+H2O) in water at 25 °C is overestimated by at least two orders of magnitude.