RATES OF THERMAL-DECOMPOSITION OF LIOH(S), LIOD(S) AND LIOT(S)

Kinetic studies on the thermal decomposition reactions, 2LiOH(s) → Li2O(s) + H2O(g), 2LiOD(s) → Li2O(s) + D2O(g), and LiOH(s) + LiOT(s) → Li2O(s) + HTO(g), have been carried out with mass spectrometric and radiometric methods over the temperature range 530-690 K. Those reaction rates were found to be of first order in the quantity of released water. The rate-constants, k, in s-1, were: kH = 1.8 × 108 exp(29 500/RT), kD = 1.7 × 108 exp(29 000/RT), and kHTO = 1.6 × 107 exp(30 700/RT), respectively. The apparent activation energy obtained for the thermal decomposition of LiOH(s), Ea = 29.5 ± 1.1 kcal/mol, coincided with a literature value of the enthalpy of reaction, ΔH°600° = 29.8 ± 1.0 kcal/mol. © 1979.