Absolute Rate Constants for the Reaction of Atomic Oxygen with Ethylene over the Temperature Range 232–500°K

Abstract

Rate constants for the reaction of atomic oxygen with ethylene were measured over a temperature range of 232–500°K using the flash photolysis‐resonance fluorescence technique. The rate constant at room temperature was also determined using a flash photolysis‐kinetic absorption spectroscopy system and a discharge‐flow system coupled to a mass spectrometer. Within the experimental errors of the three techniques, good agreement was found for the rate constant at 298°K. The bimolecular rate constant was also found invariant to changes in both total pressure and reactant concentration. Over the temperature range of the experiments, the rate data could be fitted by a simple Arrhenius expression of the form, $${\text{k=5.42± 0.30× 10}}^{\text{−12}}\hspace{0.17em}\exp \text{[(−1130± 32\hspace{0.17em}}{\mathrm{cal\; mole}}^{\text{−1}}\mathrm{)/RT]}{\mathrm{cm}}^3{\mathrm{molecule}}^{\text{−1}}·{\sec }^{\text{−1}}.$$