Calorimetric search for reliable excess enthalpy data as a function of temperature

Abstract

In the search of a useful method for determining excess enthalpies as a function of temperature Calvet calorimetry was employed. To this end, excess molar enthalpies $$P = {a \over {t_{\lim } + b}}$$ at 298.15 and 333.15 K and excess molar heat capacities $$P = {a \over {t_{\lim } + b}}$$ within 283.15–333.15 K were determined for the 1-decanol+n-decane system over the whole composition range. An isothermal flow Calvet-type calorimeter was used for $$P = {a \over {t_{\lim } + b}}$$ measurements, whereas $$P = {a \over {t_{\lim } + b}}$$ were determined by means of a Setaram Micro DSC calorimeter. Excess enthalpies within 283.15–333.15 K were indirectly obtained through the integration of $$P = {a \over {t_{\lim } + b}}$$ (T) data using $$P = {a \over {t_{\lim } + b}}$$ at 298.15 K. The results obtained at 333.15 K agreed with those determined directly, implying the thermodynamic consistency of the measured data and, therefore, the reliability of the indirect method.