Locus of Binary and Ternary Azeotropes in Chloroform-Methanol-Acetone Mixture

Initializing live version
Download to Desktop

Requires a Wolfram Notebook System

Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.

Consider a ternary mixture of chloroform, acetone, and methanol at . The vapor-liquid equilibrium (VLE) behavior is described by a modified form of Raoult's law with activity coefficients predicted by the Wilson model [1].


This mixture presents four azeotropes, whose compositions and boiling points are:

This Demonstration shows the density plot of the function . At azeotropes, and thus ; also for pure components (i.e., at the vertices of the triangle).

This mixture presents three binary azeotropes and a ternary azeotrope. Azeotropes and pure components can be readily identified by the orange-colored regions. You can drag the locator to display the corresponding value of the function . Locator coordinates (i.e., the mole fractions of chloroform and acetone in the liquid phase) are displayed in the upper-right corner. The last snapshot shows a situation where the value of is very small near the ternary azeotrope, .


Contributed by: Housam Binous and Brian G. Higgins (September 2011)
Open content licensed under CC BY-NC-SA




[1] G. M. Wilson, "Vapor-Liquid Equilibrium XI: A New Expression for the Excess Free Energy of Mixing," Journal of the American Chemical Society, 86(2), 1964 pp. 127–130.

Feedback (field required)
Email (field required) Name
Occupation Organization
Note: Your message & contact information may be shared with the author of any specific Demonstration for which you give feedback.