In this paper, we calculate the second virial coefficient for binary mixtures of Ar with CH4 and CO in order to evaluate the performance of equations of state (EOSs). The investigated EOSs are van der Waals (vdW), Redlich-Kwong (RK), Peng-Robinson (PR), Carnahan-Starling–van der Waals (CS-vdW) and Guggenheim-van der Waals (G-vdW) based on van der Waals model. In our work, we also use Dieterici ...