Volumetric properties of imidazolium-based ionic liquids using Song and Mason equation of state

The major objective of this paper is the application of a reliable model to describe volumetric properties of imidazolium-based ionic liquids. In this regard, we have applied the Song and Mason equation of state for [Bmim][PF6], [C2mim][NtF2], [C3mim][NtF2], [C6mim][NtF2], [C7mim][NtF2], [C2mim][EtOSO3], [Bmim][MeSO4], [Bmim][OcSO4], [C4mim][dca], [Bmim][BF4], [hmim][PF6], [omim][PF6] and [omim][BF4]. This equation of state consists of three temperature dependent parameters. These parameters have been calculated as functions of reduced temperature with the use of a law of corresponding states. It is shown that knowledge of liquid density at the normal boiling point and normal boiling temperature are sufficient to predict the volumetric properties of these ionic liquids. We have taken 2469 experimental points for 13 ionic liquid to show the reliability of the present equation of state. The overall average absolute deviation is 1.06%. A comparison of the predicted results, using the present equation of state (which needs just two input parameters) with the results of some previous equations of state (needing 3 input parameters) indicates that this equation of state is more accurate than those.