Azeotropic line determination from the caloric data on binary stratifying systems

The experimental isochoric heat capacity values of stratifying n-hexane-water mixtures of the compositions 0.120, 0.166, 0.200, and 0.256 H₂O mole fractions were obtained using a high-temperature adiabatic calorimeter over the density ranges 244.74–498.25, 121.06–438.21, 252.02–500.00, and 208.11–398.88 kg/m³, respectively. The C _{V, x} heat capacities were tabulated for the mixture with 0.120 H₂O mole fractions. Liquid-liquid and liquid-gas phase equilibrium curves were plotted. The suggestion was made that the intersection point between these curves characterized the state of an azeotrope. The azeotropic line with the critical point at its end was constructed.