New Thermodynamic Consistency Test for Isobaric Vapour-Liquid Equilibrium Data

A thermodynamic consistency test for the vapour-liquid equilibrium data obtained under isobaric conditions is proposed. According to this procedure, the coexistence equation with correction term for the nonideality of the vapour phase was used. The differential equation has two singulier points and was solved by numerical integration according to the method predictor-corrector Adams combined with the classical Runge-Kutta method. The nonideality of the vapour phase is considered by using the second coefficients from the virial equation of state. The residuals of the vapour phase obtained as differences between the calculated, respectively experimental values were statistically analysed to detect systematic and random errors. In this order Student and Abbe tests were used. A study of the influence of the method and the step of the integration is also presented. In this order Runge-Kutta and Adams methods were compared and for the estimation of the second virial coefficients different published procedures have been taken into account. In this paper the method of Tsonopoulos and Hayden - O'Connell are taken into account. A correlation analysis is performed to evaluate the results of this study. This revised version was published online in July 2006 with corrections to the Cover Date.