The three-parameter corresponding states principle

Abstract

A multiproperty approach for the evaluation of the existing three-parameter corresponding states principles (CSP) and calculation of the corresponding states parameter is presented. This technique is based on the assumption that contribution of the third parameter to the thermophysical properties is much smaller than the contributions of the first two parameters. The first two parameters are, generally, the molecular energy and length parameters, e/k and σ (or critical temperature and volume, T c and V c ). Based on the present multiproperty technique, several existing three-parameter CSPs are evaluated. It is demonstrated that the three-parameter CSP, which is based on the two- and three-body intermolecular potential parameters, effectively satisfies the requirements of this technique. The corresponding states parameters of several compounds, including normal alkane hydrocarbons (CH4 to C20H42), for which proper thermophysical data are available, are calculated through the present technique, and they are reported here.