Solid-Liquid and Liquid-Liquid Equilibrium in the Formamide-Acetophenone System

Solid-liquid (s-l) and liquid-liquid (l-l) equilibrium was determined in the binary system formamide-acetophenone. The s-l equilibrium was measured by recording time-temperature cooling and warming curves. The l-l equilibrium was obtained in a wide range of temperatures by the turbidity method. A considerable supercooling preceding solidification made it possible to examine metastable l-l equilibrium yet at temperatures lower than the solidus ones. Activity coefficients evaluated from the stable region of l-l equilibrium were correlated by Novak's modification of the Wilson equation. Calculation of the s-l equilibrium was performed with the obtained parameters. Heat capacity of solid and liquid acetophenone was measured and its dependence on temperature is given. The transition enthalpy betwen two solid modifications of acetophenone is also given.