Rate coefficient for the BrO+HO2 reaction at 298 K

The kinetics of the BrO + HO2 reaction (1) have been studied using the technique of ash photolysis/time resolved UV absorption spectroscopy. BrO and HO2 radicals were generated via the Br + O-3 and Cl + CH3OH/O-2 methods respectively. The rate coefficient for the reaction was found to be k(1) = ( 2.35 +/- 0.82) x 10(11) molecule(-1) cm(-3) s(-1) at 298 K and 760 Torr O-2. Uncertainty limits correspond to combined 2 standard deviation statistical variation and systematic factors. This result is briefly compared with previous determinations of k(1). A study of the enhancement of the HO2 self-reaction rate in the presence of methanol was also performed, with the observed second-order loss rate coefficient given by k(obs) = (2.9 x 10(-12) + alphabeta[CH3OH])/(1 + alpha[CH3OH])(2), with alpha = (6.15 +/- 0.90) x 10(-19) molecule(-1) cm(-3) and beta = (3.2 +/- 0.5) x 10(-11) molecule(-1) cm(-3) s(-1) at 298 K and 760 Torr O-2, for [CH3OH] less than or equal to 5.5 x 10(17) molecule cm(-3).