Correlation of Excess Energies of Electron-Impact Dissociations with the Translational Energies of the Products

Abstract

Translational energies of products of unimolecular dissociations resulting from electron impact have been measured at the appearance potentials of the fragment ions. Excess energies for each process were determined from the measured appearance potentials and the known heats of formation of ground-state products and reactants. Results are compared with the predictions of the statistical theory and found to be in agreement if the classical density of states is used. Application of the method to accurate determinations of heats of formation of radicals and radical ions is demonstrated.