Determination of electron affinities. Part 8.—Carbon tetrachloride, chloroform and hexachloroethane

Abstract

The electron affinities of CCl₄, CHCl₃ and C₂Cl₆ have been determined by the magnetron method and are found to have respectively the following mean values at the stated temperatures: 52.6 (1240°K), 44.2 (1250°K) and 37.9 kcal (1270°K). These values referred to 0°K are 48.9, 40.5 and 34.1 kcal respectively. In addition, the electron affinities of the CCl₃ and C₂Cl₅ radicals are 37.5 kcal at 1540°K and approximately 40 kcal at 1470°K becoming 33.1 kcal and approximately 35 kcal respectively at 0°K. In CCl₄ the first bond dissociation energy D(CCl₃—Cl) is found to be 69.9 kcal and in CHCl₃ the CCl₃—H bond dissociation energy is calculated to be 91.4 kcal, both at 0°K. A process involving the adsorption of chlorine atoms on the platinum filament is observed and the heat of adsorption found to be 36.7 kcal at 1430°K.