J. D. van der Waals
J. D. van der Waals was a Dutch scientist from Leiden who developed the first equation of state p(V,T) in his doctorate in 1873, which could also be used to calculate the liquid phase, phase equilibria of fluids and the critical point. He took into account the repulsion of molecules and their attractive interaction with their intrinsic volume. Phase equilibria of binary mixtures could also be calculated using mixing rules in which the parameters are averaged in a suitable manner. Today, equations of state for real fluids are the basis for modeling countless technical processes such as distillation, extraction or particle production, etc.