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Kinetics of the reaction of HO 2 with NO
Author(s) -
Howard Carleton J.,
Evenson K. M.
Publication year - 1977
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl004i010p00437
Subject(s) - exothermic reaction , reaction rate constant , torr , radical , kinetic energy , analytical chemistry (journal) , kinetics , reaction rate , molecule , chemical kinetics , order of reaction , chemistry , chemical reaction , materials science , thermodynamics , physics , organic chemistry , quantum mechanics , catalysis
The gas phase reaction of HO 2 radicals with NO was studied using a discharge‐flow system and laser‐magnetic resonance detection. Concentrations of HO 2 down to 2 × 10 9 molecules/cm³ were detectable, thus allowing the reaction to be studied under pseudo‐first‐order kinetic conditions. The rate constant was measured using three independent kinetic schemes, one of which involved the detection of the reaction products OH and NO 2 . The three schemes gave results in excellent agreement. The rate constant, k 1 , for the reactionHO 2 + NO → OH + NO 2( 1 ) is (8.1 ± 1.5) × 10 −12 cm³/molecule·s at 296K and a pressure of 140‐220 Pa (1.1‐1.7 torr). The measurements also indicate that the rate constants for two other exothermic channels of the reaction are less than 2% of k 1 .