Methane—Tritium System. II. Kinetics of the Exchange Reaction

The rates of the reactions of CH4 with T2 to give, successively, CH3T, CH2T2, CHT3, and CT4, and of the reverse reactions of the tritiated molecules with protium were measured. Second-order rate constants were obtained from the data, and radiation yields were determined. The reactions were shown to follow two paths. Beta decay energy deposited in the tritium resulted in an exchange reaction in which approximately one exchange took place per ion pair formed. Energy initially deposited in the methane resulted in six exchanges per ion pair. Equilibrium constants were calculated from the steady-state concentrations and were shown to be close to the high-temperature, classical values. Hot atom, ion, and radical reactions are believed to play a predominant role in the exchange.