Discharge Flow Measurements of the Rate Constants for the Reactions OH+SO2+He and HOSO2+O2 in Relation with the Atmospheric Oxidation of SO2

Article abstract of DOI:10.1021/j100408a061

The reactions OH+SO2+M (M=He, SO2)->HOSO2 (1) and HOSO2+O2 (2) have been studied by the discharge flow EPR technique at room temperature and at pressures ranging from 1 to 6.4 Torr in a halocarbon-wax-coated reactor.For He and SO2 as the third body the bimolecular rate constant can be expressed as k1(He)=(8.1+/-0.2)*10^-32+(2.4+/-0.4)*10^-15 (P=1-6.4 Torr) and k1(SO2)=(1.3+/-0.4)*10^-30 (P<*>0.1 Torr).Units are cubic centimeters per molecular per second.Reaction 2 was studied by adding O2 to the reacting medium and NO for the conversion of HO2 into OH.The value of k2 was found from the computer fitting of the OH profiles with and without added O2 as a function of reaction time: k2=(3.5+/-1)*10^-13 cm³ molecule^-1 s^-1.