Mass spectrometric determinations of the rates of elementary reactions of NO and of NO2 with ground state N4S atoms
- 1 January 1975
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases
- Vol. 71, 2189-2202
- https://doi.org/10.1039/f19757102189
Abstract
Kinetic studies of the reactions of NO, (1) and of NO2, (2), with N 4S atoms have been made using direct mass spectrometric detection of N atoms in a discharge flow system. The rate constant k1(cm3 molecule–1 s–1) for the rapid reaction (1), N + NO [graphic omitted] N2+ O (1), has been determined with pseudo first-order kinetic analysis ([NO]0/[N]0 1). The mean value for k1 was (2.2 ± 0.2)× 10–11 at 298 K, and between 298 and 670 K, k1 was given by the expression (8.2 ± 1.4)× 10–11 exp[–(410 ± 120) K/T]. Similar kinetic studies of the N + NO2 reaction, using pseudo first-order analysis with very large excesses of NO2([NO2]0/[N]0 > 80), showed the rate constant for this reaction to be an order of magnitude less than the literature value. However, at lower values of [NO2]0/[N]0, much greater apparent rate constants for the N + NO2 reaction were obtained, similar to those found previously. These high values are attributed to a rapid catalytic cycle capable of removing both N atoms and NO2, i.e., N + NO2 [graphic omitted] N2O + O (2A), O + NO2 [graphic omitted] NO + O2(3), N + NO [graphic omitted] N2+ O (1). Reactions (1)+(3) have the stoichiometry, N + NO2→ N2+ O2: No evidence was found from N2O yields in the N + NO2 reaction for any reactive channel involving N + NO2 other than reaction (2A). The results give a mean value for k2A equal to (1.4 ± 0.2)× 10–12 cm3 molecule–1 s–1 at 298 K.Keywords
This publication has 0 references indexed in Scilit: