Farkhondeh Mozaffari

In this work, we have extended Song and Mason equation of state with a simple modification to imidazolium and phosphonium based ionic liquids. Four temperature-dependent parameters in the equation of state have been calculated as functions of reduced temperature with the use of the law of corresponding states. It is shown that the knowledge of surface tension, liquid density at the room temperature and two other constants that are obtained by fitting against experimental data is sufficient to predict the PVT properties of these ILs. Predicted densities are in good agreement with experimental literature data in a wide range of temperatures, 273.15–472.6 K, and pressures, 0.1–200.0 MPa. The overall average absolute deviation of calculated densities from literature values for 3302 data points of 17 ionic liquids was found to be 0.89%. Moreover, we indicate that the Zeno line regularity can well be predicted by proposed model for ILs. Also, we have demonstrated the density behavior of studied imidazolium based ILs in terms of the chain length of alkyl group of cation using modified SM EOS.