Prediction of Density and Excess Properties of Binary Mixtures Using the Modified GMA Equation of State

Document Type : Research Article


1 Department of Chemistry, University of Isfahan, Isfahan, I.R. IRAN

2 Department of Chemistry, Payame Noor University, Tehran, I.R. IRAN


The formulation of the fluid properties in terms of its affecting variables is important in practical works that cannot be tested in the laboratory. In this work, the modified GMA equation of state which was developed with the (3, 6, 9) average intermolecular potential, has been used for the description of the behavior of the binary mixture. The application of the equation of state for some binary mixtures was investigated and the temperature dependence of its parameters in different mole fractions was determined. It is found that the parameters of the equation of the state obey the cubic mixing rule. The excess volume, excess internal energy, and excess enthalpy of the studied mixtures were calculated in the different temperatures and mole fractions using the equation of state and compared with the experiment. Good compatibility of the predicted values with the experiment indicates the ability of the equation of state in the prediction of such properties. Furthermore, the existence of the common intersection point in the isotherms of the excess enthalpy of ethanol-methyl cyclohexane, cyclohexane-n-hexadecane, TEGME-HFC-134a, and propane-isobutene mixtures show that the temperature dependence of the excess enthalpy in this mole fraction is very low and consequently, the value of excess heat capacity in this mole is nearly zero. An expression was obtained for the mole fraction of the common intersection point that more experimental data needs to approve.


Main Subjects

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