Here our motivation is to build upon the work of Elliott and Lira , and present an alternative discussion and motivation for eq. ( ) to explain the linearity of ln P sat versus 1/T. Within our discussion here we will consider the case of water and hexane, using reference data readily available from the "Thermophysical Properties of Fluid Systems" by NIST . MATLAB code used for all of the analysis and figures is provided in the supporting information accompanying the electronic version of this manuscript, along with additional systems that may be used as an example. The goal of the MATLAB code is to provide a useful resource for undergraduate thermodynamics students.