Reaction of hydroxyl radicals with NO, NO2 and SO2

Abstract

The reactions of OH with NO, NO₂ and SO₂ have been studied in a discharge-flow system, using resonance fluorescence for the determination of [OH]. Rate constants were obtained, for the loss of OH, which were effectively third order at pressures of a few Torr with M = Ar and N₂. Values of 7 ± 2 × 10^–31, 1.5 ± 0.5 × 10^–30, 4.5 ± 1.5 × 10^–31 cm⁶ molecule^–2 s^–1 were obtained for reactions with NO, NO₂ and SO₂, respectively, with Ar as third body; with M = N₂, the rate constants were 15 ± 5 × 10^–31, 2.6 ± 1.0 × 10^–30 and 7.2 ± 2.6 × 10^–31 cm⁶ molecule^–2 s^–1. Possible implications of the results are discussed in relation to the chemistry of ambient and polluted atmospheres.