Equations for the Ideal method

The following equation shows Raoult's Law:

where

xi is the liquid phase mole fraction of component i

yi is the vapor phase mole fraction of component i

Pisat is the vapor pressure of pure component i at the temperature of the system

The product on the left side of this equation (yiP) is known as the partial pressure of component i.

We calculate the liquid phase fugacity coefficient according to the following equation:

We can rewrite this equation as:

For ideal systems, the activity coefficient is 1:

For ideal systems, the vapor phase fugacity coefficient is 1: