Effect of nitric oxide on hydrogen formation in irradiated HCl

Abstract

Nitric oxide reduces the production of hydrogen in irradiated HCl and leads to ClNO formation. The results can be interpreted on the basis of a competition between HCl and NO for H atoms and (HCl)x− negative ion intermediates. The yield of (HCl)x− = 2.4 ± 0.3 per 100 eV is similar to that found from experiments with chlorine, as was the total yield of scavengable H atoms plus electrons, ge + gH. From analyses of the competition kinetics for experiments both with and without added SF6, the ratio of the termolecular rate constant for reaction of H with NO in the presence of HCl as third body to that for reaction of H with HCl was estimated to be 6.3 ± 0.8 × 10−19 cm3 molecule−1 at 298 K.