Kinetic study of the reaction of F with H2 and CF3H by ESR methods

Abstract

The reactions between F and H2, H and F2, and F and CF3H were studied by using a fast flow reactor with electron spin resonance detection. The reaction rate constant for F+H2→HF+H was determined to be 1.00±0.08×1013 cm3 mole−1⋅sec−1 at 298 °K. The rate of the reaction H+F2→HF+F was determined in a system where known amounts of F and F2 were injected into a stream of H2 in He. Using finite difference techniques to solve the rate equations, the rate constant was found to be 0.26±0.06×1013 cm3 mole−1⋅sec−1. These reaction rates are in good agreement with other published values. The rate constant determined for the reaction F+CF3H→HF+CF3 was 0.90±0.08×1011 cm3 mole−1⋅sec−1. Techniques are presented which permit ESR to be used in studies of complex reaction mechanisms and in nonuniform flow velocities.