The activity coefficient i can be estimated by the use of the Wilson equation. The Wilson equations for binary systems containing two components indicated as 1 and 2 have the form

Image No 1

where 1 and 2 denote activity coefficients of the components 1 and 2, respectively. The Wilson parameters _12 and _21 are expressed by

Image No 2

where V1 and V2 are the molar volumes [cm3.mol−1] of component 1 and component 2; A21, A12 - interaction energy parameters [cal.mol−1] between unlike molecules, in which A12(= _12 − _11) and A21(= _21 − _22) are the cross-interaction energy parameters, independent of temperature and composition; R - universal gas constant [J.mol−1.K−1]; T - temperature [K]. The activity coefficients at infinite dilution provide a good basis for the initial estimate of the parameters of the Wilson’s equation for binary systems,

Image No 3

Several methods were developed for the measurement of activity coefficients at infinite dilution. The most important methods are: gas-liquid chromatography (GLC), non-steady-state gas-liquid chromatography, differential ebulliometry, static methods and the dilutor method. The simple experimental method for rapid determination of activity coefficients at infinite dilution is based on gas-liquid chromatography.

Dear Eman El-Gendy

https://www.btxonline.com/media/wysiwyg/tab_content/BTX%20Manual%20Plate%20Handler.pdf

Regards

Maytham

Is wilson equation for ternary mixture the same as for binary mixture ? and how can I get wilson's parameters ?

Using the nonlinear least-squares method coupled with use of the Q function as an objective function, we calculated the Wilson parameters A12 and A2\ for fifteen binary systems at one atmosphere and predicted the vapor-liquid relations for five ternary mixtures.

you can read the attached paper … please don't hesitate to contact me when you need

best regards

raghd