Relative rate constants for abstraction of hydrogen by methyl radicals from ethane and from ethylene

Abstract

A method is described for the measurement of relative rate constants for abstraction of hydrogen by methyl radicals from ethane and from ethylene based on the effect of the addition of small quantities of ethane on the rates of formation of products in the thermal reactions of ethylene. The ratio of rate constants for reactions[Formula: see text]over the temperature range 673–733 K was given by the following expression:[Formula: see text](R = 1.987 cal mol−1 deg−1). Using a value of k4, from the literature the following expression was obtained for k3, over the same range of temperature:[Formula: see text]It was concluded that a previous measurement of k3 in a lower range of temperature was too close to the value of k4.