Dissociation of Cl2 in Shock Waves

Abstract

The dissociation of Cl2 in Cl2–Ar mixtures was measured in a shock tube over the temperature range 1700° to 2500°K. Direct absorption spectrophotometry was used to follow the course of the reaction. A rate constant given by k=8.90×1013 exp —48 300/RT cm3/mole-sec [or,alternatively,k=3.13×1012(57 080/RT)2.087exp−57 080/RT cm3/mole·sec]was found to fit the measured data over the entire temperature range with a most probably error of ±6%. The activation energy determined agreed exactly with that measured by Hiraoka and Hardwick although the over-all rate constants were a factor of 10 lower than those reported by these investigators. Recombination rate constants, calculated from the measured dissociation rate constants by use of the thermodynamic equilibrium constant, were found to be in good agreement with the theoretical predictions of Benson and Fueno.