TEMPERATURE-DEPENDENCE OF THE RATE-CONSTANT FOR THE HO2+BRO REACTION

The rate constant for the HO2 + BrO reaction has been measured using t he turbulent flow technique with high-pressure chemical ionization mas s spectrometry for the detection of reactants and products. At room te mperature and 100 Ton pressure, the rate constant (and the two standar d deviation error limit) was determined to be (1.4 +/- 0.3) x 10(-11) cm(3) molecule(-1) s(-1). The temperature dependence of the rate const ant was investigated between 298 and 210 K, and the data was fit to th e following Arrhenius expression: (2.5 +/- 0.8) x 10(-12) exp[(520 +/- 80)/T] cm(3) molecule(-1) s(-1). Although the negative activation ene rgy value agrees well with the current recommendation for stratospheri c modeling, our absolute values for the rate constant are about a fact or of 2 lower than this same recommendation.