Liquid-liquid equilibrium and heat capacity for the critical binary solution of {n-decane + benzonitrile}

Abstract

The liquid-liquid coexistence curve in a temperature range of about 8 K from the upper consolute point and the specific isobaric heat capacity in a wide temperature range for the critical binary solution of {n-decane + benzonitrile} have been precisely measured. The upper consolute mole fraction xc of benzonitrile and the upper consolute temperature Tc were determined to be xc = 0.530, Tc = 286.930 K, respectively. From the data collected near the upper consolute point, the critical exponents corresponding to the heat capacity and the coexistence curve were deduced and found to be consistent with the theoretical predictions of the 3D-Ising universality. The chain-length dependences of the critical properties were investigated, and the asymmetric behavior of the coexistence curve was analyzed based on the complete scaling theory, which confirmed that the heat capacity related term was of importance.