Mass Spectrometric Studies of Atomic Reactions. III. Reactions of Hydrogen Atoms with Nitrogen Dioxide and with Ozone

The reaction of H atoms with excess NO2 results in the production of one NO molecule for every NO2 molecule consumed and the consumption of 1.5±0.1 NO2 molecules per H atom initially present. The secondary reactions are rapid and make the over‐all reaction very suitable for H‐atom titration. A mechanism is proposed to explain these results. The reaction of H atoms with excess O3 results in the consumption of 3.1±0.2 O3 molecules for each H atom initially present. Addition of H2 and N2O to the system showed that vibrationally excited OH formed in the initial reaction decomposes O3. Other mechanisms for the additional O3 consumption are discussed. The rate constant for the primary step was found to be (4.8±0.5) × 10—11 cm3 molecule—1 sec—1 for the NO2 reaction and (2.6±0.5) × 10—11 cm3 molecule—1 sec—1 for the O3 reaction.