Reaction H+C2H4: Investigation into the effects of pressure, stoichiometry, and the nature of the third body species

The detection of H atom concentrations by Lyman α photometry has been employed in a time resolved experiment to obtain the pressure dependence of the apparent bimolecular rate constant for the reaction of H atoms with C2H4 at room temperature. A computer simulation analysis has been applied to adjust the observed rate constants for H atom depletion in reactions subsequent to the initial reaction. The pressure falloff behavior at low pressures of various heat bath species He, H2, N2, Ar, Ne, Kr, and SF6 were also obtained. Experiments at high pressures of He have permitted an extrapolation to the high pressure limit of the rate constant of (16.1± 3.2) × 10−13 cc molecule−1· sec−1.