Desorption enthalpy, complex transition

Table 6.5 Desorption enthalpies of Mg- and Ca-based complex transition metal hydrides...

In addition to chemical reactions, the isokinetic relationship can be applied to various physical processes accompanied by enthalpy change. Correlations of this kind were found between enthalpies and entropies of solution (20, 83-92), vaporization (86, 91), sublimation (93, 94), desorption (95), and diffusion (96, 97) and between the two parameters characterizing the temperature dependence of thermochromic transitions (98). A kind of isokinetic relationship was claimed even for enthalpy and entropy of pure substances when relative values referred to those at 298° K are used (99). Enthalpies and entropies of intermolecular interaction were correlated for solutions, pure liquids, and crystals (6). Quite generally, for any temperature-dependent physical quantity, the activation parameters can be computed in a formal way, and correlations between them have been observed for dielectric absorption (100) and resistance of semiconductors (101-105) or fluidity (40, 106). On the other hand, the isokinetic relationship seems to hold in reactions of widely different kinds, starting from elementary processes in the gas phase (107) and including recombination reactions in the solid phase (108), polymerization reactions (109), and inorganic complex formation (110-112), up to such biochemical reactions as denaturation of proteins (113) and even such biological processes as hemolysis of erythrocytes (114). 

Complex metal hydride solid-state compound containing homoleptic, anionic metal-hydrogen complexes d, d, d etc electron configuration of transition element h.H enthalpy of hydride formation as determined from pressure-composition isotherms during desorption by using van t Hoff s method... 

Phase transitions of starch-Upid complexes are also seen in calorimetric curves. These weak endothermic phenomena occur around lOOX and have enthalpies of less than 30 J/g DM [57]. Sometimes interactions between water and the foods or food constituents (dissolution, absorption, or desorption) in addition to interactions of cations and sugars in water are studied [102-104]. 

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