Rate Constant of the Reaction of OH Radicals with HBr over the Temperature Range 235–960 K

The kinetics of the reaction hydroxyl radicals with HBr, important in atmospheric and combustion chemistry, has been studied a discharge flow reactor combined an electron impact ionization quadrupole mass spectrometer temperature range 235–960 K. rate constant OH + HBr ? H2O Br (1) was determined using both relative method (using Br2 as reference) absolute measurements, monitoring consumption under pseudo-first-order conditions excess HBr. observed U-shaped dependence k1 is well represented by sum two exponential functions: = 2.53 × 10–11 exp(?364/T) 2.79 10–13 exp(784/T) cm3 molecule–1 s–1 (with estimated conservative uncertainty 15% at all temperatures). This expression for k1, recommended T 240–960 K, that from previous low studies, 1.06 (T/298)?0.9 23–240 allows to describe behavior over extended 23–960 current direct measurements temperatures above 460 only ones date, provide experimental dataset use volcanic plume modeling basis test theoretical calculations.