Generalized vapor pressure behavior of substances between their triple points and critical points

Several approaches are utilized for the estimation of the parameters associated with the normalized vapor pressure equation\documentclass{article}\pagestyle{empty}\begin{document}$$ \ln P_R = \alpha + \frac{\beta }{{T_{R^m } }} + \gamma T_{R^7} $$\end{document}to develop a capability for the prediction of vapor pressures consistent with the theorem of corresponding states. In this development, conditions and restrictions associated with the critical point and the normal boiling point were used to establish the vapor pressure parameters α, β, γ, and m . For the evaluation of these parameters, five different approaches were applied, and vapor pressures calculated with each of them were compared with corresponding experimental values presented in the literature. These comparisons were further examined using the results of four other well‐known vapor pressure equations available in the literature. This evaluation included 138 substances of all types and involved a total of 7,633 literature reported vapor pressure values to show that improved results are possible through the involvement of the generalized vapor pressure equation of this investigation.