Thermodynamic Properties as a Function

The integral in equation (11.137) must be evaluated numerically. Table A6.7 of Appendix 6 gives the heat capacity and other thermodynamic properties as a function of 0d/T. It can be used to obtain values for the thermodynamic properties as a function of the temperature. 

FIGURE 7-7 Schematic diagram of excess thermodynamic properties as a function of solution composition (various properties can be negative, depending on the system). 

Many equations, either empirical or derived from models, are available to represent excess thermodynamic properties as a function of the liquid mole fraction and of a number of adjustable parameters for use in Equations 4.3 and 4.4 (Prausnitz, Lichtenthaler, and Gomes de Azevedo 1999). In the treatment of our experimental data, we have examined the capability of many of these equations to fit data with the smallest number of parameters and with the least standard deviation of the O.F. (Lepori et al. 1998). For the majority of systems, either binary or ternary, examined by us in the course of about two decades, the rational form (Myers and Scott 1963) of the Redlich-Kister (RK) expression (Redlich and Kister 1948), and the Wilson (Wilson 1964) equation in the extended form (Novtik, MatouS, and Pick 1987), have resulted in the most appropriate representations of and For ternary systems, the excess functions can be expressed as the sum of a contribution (subscript B), which depends only on the parameters of the three binary systems, and a ternary contribution (subscript T), which involves additional parameters. 

Source Calculated from L. V. Gurvich et al., "Thermodynamic Properties as a Function of Temperature," in CRC Handbook (rf Chemistry and Physics (1913-1995), 75th Edition (Special Student Edition), editor-in-chief,... 

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