Thermodynamic Calculation of a Heat of First-Order Phase Transitions

Sobko AA

Abstract

A transition heat is the most important characteristics of first-order phase transitions. Black [1] was first who discovered in 1762 that in the transfer of water to vapor, some quantity of heat is absorbed, which he termed the latent evaporation heat. In spite of more than the two-hundred-year period of the heat transfer concept existence there are no analytical expressions relating the transition heat with other parameters of phase transitions. For example, the fundamental "Physics Encyclopedia", articles devoted to the transition heat, evaporation heat, and so on, comprises no formulae but only tables of experimental data. One can also mention monographs [2-9] which have no relationships except for the conventional definition of the transition heat λ=TΔS. Hence, obtaining the relationships between the transition heat and other parameters of first-order phase transitions will be a substantial contribution into the theory of first-order phase transitions.