Correlation model to estimate the thermodynamic properties

A technique for constructing the correlation dependencies of the thermodynamic properties of similar compounds was proposed. This technique is based on the Taylor expansion in the supposed analytic relationship between properties. The constructed correlation dependencies were used to estimate the thermodynamic properties of the condensed bromides and iodides of hafnium HfG(n) (G = Br, I and n = 1, 2, 3, 4) and the compounds formed in the PbO-SiO2 system. Standard formation enthalpy Delta H-298(o), entropy S-298(o), heat capacity C-p,298(o) and temperature dependencies C-p(T) at temperatures T = 298 k to 3000 k were estimated. The standard estimation error of the thermodynamic properties of the compounds in the PbO-SiO2 system does not exceed 2% for all the estimated properties. For condensed halides, the standard estimation error was (1) S < 8% for enthalpy, (2) S < 5.6% for entropy, (3) S < 4.6% for heat capacity.