Equation of state of dense systems due to multiple interactions many-particle at the molecular level is very complex. However, in recent years several equations of state for dense systems is presented but each has their own strengths and weaknesses and only used for special systems. Equations of State for mixed binary and ternary systems are more complex than pure liquid. Of course, in fluids such as mixed ionic liquids because of the multiple ions, this complexity is more and depends trongly on the temperature of the system and less on the pressure. Given to the importance of equation of state and its usage in industry, an empirical mode function (correlation function) that is proposed before for pure ionic liquids extended to mixed ionic liquids and its ability to predict the volume, pressure compressibility factor and isothermal compressibility factor of the liquid mixture of ionic and nonionic has been evaluated. To achieve this purpose, some important mixing rules has been chosen and tested. The results show success of these correlation functions in predicting simultaneously of volume, pressure compressibility factor and also isothermal compressibility factor. Due to the importance of excess volumes of the liquid mixture, a new correlation function for the excess volume is proposed with good accuracy in predicting this important quantity.
