  The description of fluid mixtures molecular behavior is significant for
various industry fields due to the complex composition of fluid found in
nature. Statistical mechanics approaches use intermolecular interaction
potential to predict fluids behavior on the molecular scale. The paper provides
a comparative analysis of mixing rules applications for obtaining
intermolecular interaction parameters of mixture components. These parameters
are involved in the density functional theory equation of state for mixtures
(Mixture DFT EoS) and characterize thermodynamic mixture properties in the
bulk. The paper demonstrates that Mixture DFT EoS with proper intermolecular
parameters agrees well with experimental mixtures isotherms in bulk for
different mixtures. However, predictions of vapor-liquid equilibrium (VLE)
experimental data are not successful. Halgren HHG, Waldman - Hagler, and
adaptive mixing rules that adjust on the experimental data from the literature
are used for the first time to obtain intermolecular interaction parameters for
the mixture DFT model. The results obtained provide a base for understanding
how to validate the DFT fluid mixture model for calculating thermodynamic
properties of fluid mixtures on a micro and macro scale.
