Limiting activity coefficients in binary mixtures of 1-alkanols and toluene

Limiting activity coefficients in binary mixtures of six lower 1-alkanols (C1–C6) and toluene were determined employing alternatively the techniques of inert gas stripping (IGS) and comparative ebulliometry (EBU). For each case, the suitable technique was chosen on the basis of the limiting relative volatility of the solute. Measurements were typically carried out at four temperatures covering a range of 30 K and were done with a good precision (1–3%). The new data were compared with available literature information on both the activity coefficient and calorimetric partial molar excess enthalpy at infinite dilution. All the critically evaluated information was merged and processed simultaneously to produce the recommended temperature dependencies of the limiting activity coefficients. The performance of leading prediction methods (UNIFAC, modified UNIFAC, ASOG, MOSCED, DISQUAC) was further examined using this data. An attempt was also made to interpret the behavior of the systems studied using a non-athermal association model.