AN INVESTIGATION OF THE REACTIONS OF NO3 RADICALS WITH CL AND CLO

The reaction (1) Cl + NO3 --> ClO + NO2 was studied at 298 K by observing the kinetic behaviour of NO3, Cl and ClO using discharge-flow mass-spectrometric technique. A rate constant k(1) = (2.26 +/- 0.17) . 10(-11) cm3 molecule-1 s-1 was obtained. The secondary processes between NO3 and ClO were also investigated and OClO was detected as a reaction product. For the rate constant of the reaction (2a) ClO + NO3 --> ClOO + NO2 an upper limit of k(2a) = 1 . 10(-13) cm3 molecule-1 s-1 was found. In contrast to previous findings it is shown that reaction (2b) ClO + NO3 --> OClO + NO2 is the predominant channel with k(2b) = (4.3 +/- 1.0) . 10(-13) cm3 molecule-1 s-1.