Rate constants of HO2 + NO covering atmospheric condition. 1. H02 + H2O2

Rate constants of the gas-phase reactions HO2 + NO -> products (1), HO2 + NO -> OH + NO2 (1a), and OH + NO -> products (2) were determined at room temperature and total pressures of 10, 50, and 100 kPa of N2. OH radicals were produced by pulsed 248 nm photolysis of H2O2 and monitored by time resolved CW UV-laser long-path absorption. Biexponential OH decay curves, observed in the presence of H2O2 and NO, were anlyzed to obtain rate constants for the above reactions. Those of reactions 1 and 1a were found to be independent of pressure with averaged values of (9.7 +- 1.5) x 10 (hoch minus)12 cm3 s (hoch minus)1, respectively. This indicates and OH yield very close to unity (> 0.95) for the title reaction under the experimental conditions of this work. (Abstract truncated)