Details

The saturation pressures were calculated using the Antoine equation:

,

where represents either benzene or toluene ( or ), is temperature (°C), and , and are Antoine constants.

The fugacity of a component depends on temperature and molar composition.

In the liquid region:

,

where is the liquid mole fraction and both and have units of bar.

In the vapor region:

,

where is the vapor molar composition and is the total pressure (bar).

When vapor and liquid are in equilibrium (VLE):

.

The screencast video at [1] explains how to use this Demonstration.

Reference

[1] Fugacities in an Ideal Binary Mixture [Video]. (Dec 1, 2016) www.colorado.edu/learncheme/thermodynamics/FugacitiesIdealBinaryMixture.xhtml.