MODELING THE THERMAL-DECOMPOSITION OF SOLIDS ON THE BASIS OF LATTICE ENERGY CHANGES - PART 2 - ALKALINE-EARTH PEROXIDES

In Part 1, the decompositions of the alkaline-earth metal (Ca, Sr, Pa) carbonates to their oxides, with the release of CO2 gas, were modeled by devising a symmetry-based sequence of steps by which the reactant structure is converted to the product structure. Lattice energies were evaluated at each step to yield energy profiles for the postulated re action processes. The observed (apparent) activation energies were com parable to the energy barriers for the postulated mechanisms, suggesti ng that the postulated mechanisms are energetically feasible. The calc ulations are repeated here (in Part 2) for the decompositions of the c orresponding alkaline-earth peroxides, The energy barriers found are l ow compared to the observed activation energies. This result is taken to suggest that the postulated processes are energetically inaccessibl e, (C) 1998 Academic Press.