Maedeh Kamel - Department of Chemistry, Payame Noor University, PB BOX ۱۹۳۹۵-۴۶۹۷ Tehran, Iran
Kamal Mohammadifard - Department of chemical engineering, Ferdowsi University of Mashhad, Mashhad, Iran

New parameters of the linear isotherm regularity, the so-called LIR equation of state, are used to calculate the bulk modulus of dense fluids. In this work, we drive an expression for the bulk modulus of dense fluids (CO, C6H6, C6H5CH3) using the linear isotherm regularity (LIR). In later stages, bulk modulus calculated by Peng - Robinson (PR) equation of state as a test of the other equation of state. Comparison of the calculated values of bulk modulus with the extended coefficients of the linear isotherm regularity with the values obtained experimentally shows the accuracy of this method to be is general, quite good.

Bulk Modulus, Dense fluids, LIR equation, Peng-Robinson equation