Reactions of hydroxyl radicals with some hydrogen halides
Abstract
The reactions of OH with HCl and HI have been studied in a fast flow system. Hydroxyl radicals were generated by NO2 titration of atomic hydrogen, and concentrations of OH, Cl , and I were determined at various reaction times from their epr spectra. At 295 K, rate constants obtained for reactions 1 and 2 were (6.4 +- 1.5) X 10^-13 and (1.3 +- 0.5) x 10^-11 cm3 molecule-1 sec-1, respectively: OH + HCl -> H2O + CI (1); and OH + HI -> H2O +I (2). Using these values, and others obtained from the literature, a comparison was made of the rate constants and activation energies of the reactions of OH with HCl, HBr and HI.