ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Mixtures of N2O, H2, O2, and trace amounts of NO and NO2 were photolyzed at 213.9 nm, at 245°-328°K, and at about 1 atm total pressure (mostly H2). HO2 radicals are produced from the photolysis and they react as follows:Reaction (1b) is unimportant under all of our reaction conditions. Reaction (1a) was studied in competition with reaction (3) from which it was found that k1a/k31/2 = 6.4 × 10-6 exp { z-(1400 ± 500)/RT} cm3/2/sec1/2. If k3 is taken to be 3.3 × 10-12 cm3/sec independent of temperature, k1a = 1.2 × 10-11 exp {-(1400 ± 500)/RT} cm3/sec. Reaction (2a) is negligible compared to reaction (2b) under all of our reaction conditions. The ratio k2b/k1 = 0.61 ± 0.15 at 245°K. Using the Arrhenius expression for k1a given above leads to k2b = 4.2 × 10-13 cm3/sec, which is assumed to be independent of temperature. The intermediate HO2NO2 is unstable and induces the dark oxidation of NO through reaction (-2b), which was found to have a rate coefficient k-2b = 6 × 1017 exp {-26,000/RT} sec-1 based on the value of k1a given above. The intermediate can also decompose via Reaction (10b) is at least partially heterogeneous.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550100106
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