Rate constant for the reaction of O(/sup 3/P) with H/sub 2/ by the flash photolysis-shock tube and flash photolysis-resonance fluorescence techniques; 504K less than or equal to T less than or equal to 2495K

The rate constant for the reaction, O(/sup 3/P) + H/sub 2/ ..-->.. OH + H, was measured over the temperature range of 504 K to 2495 K by two independent experimental methods. The flash photolysis-shock tube (FP-ST) technique, combined with atomic resonance absorption spectroscopy (ABAS), was used over the temperature range 880K to 2495K. The results from the FP-ST work, expressed in simple Arrhenius form are included. The flash photolysis-resonance fluorescence (FP-RF) technique was utilized to measure rate constants from 504 K to 923 K. Results from the FP-RF experiments, also expressed in simple Arrhenius form are included. These kinetic results for the reaction of O(/sup 3/P) with H/sub 2/ exhibit non-Arrhenius behavior. This conclusion is confirmed by the recent kinetic data of Presser and Gordon (297K less than or equal to T less than or equal to 471K). The combined results from these three data sets are expressed by three parameter fit. The estimated error in this expression is about +-30% over the entire temperature range, 297K to 2495K. Rate constants for reaction (1) from recent ab initio calculations are in excellent agreement with these experimental results. 49 refs., 3 figs., 3 tabs.