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Title: Direct determination of the activation energy for the reaction of nitric oxide with ozone

Thesis/Dissertation ·
OSTI ID:5105044

The activation energy for the reaction of nitric oxide with ozone has been directly measured as a function of temperature. The instrument constructed for this study consisted of two flow tubes that are connected together at each end, where the reaction zone temperature of each flow tube was controlled independently. The reaction of nitric oxide and ozone was pseudo-first order ((NO)/(O/sub 3/) greater than or equal to 250) and studied by following the reduction of the chemiluminescence of one of the products (NO/sup *//sub 2/(/sup 2/B/sub 1,2/)) of the reaction. The chemiluminescence was measured using a microcomputer-controlled photon counter designed for these studies. The activation energy has been found to vary with temperature. The activation energy varies from 2390 +/- 10 calories at 216 K to 2970 +/- 60 calories at 333 K. The variation over the complete temperature range studied (204-353 K) is large enough (650 calories) that the errors associated with the method cannot account for all of the variation. There are other pathways for this reaction other than ground state reactants going to ground state products, and their contribution to the activation energy (approx.500 calories) has been found to be sufficient to account for the observed variation with temperature when added to the variation predicted by either transition state (180 calories) or collision (150 calories) theory.

Research Organization:
Illinois Univ., Urbana (USA)
OSTI ID:
5105044
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English