DENSITIES, REFRACTIVE-INDEXES, AND EXCESS PROPERTIES OF MIXING OF THEN-HEXANOL PLUS ETHANENITRILE PLUS DICHLOROMETHANE TERNARY-SYSTEM AT 25-DEGREES-C

Excess molar volumes and excess refractive indexes of the n-hexanol ethane-nitrile + dichloromethane system and the three corresponding bi nary mixtures have been determined at 25 degrees C, by measuring densi ties and refractive indexes. Different expressions exist in the litera ture to predict these excess properties from binary data. The empirica l correlation of Cibulka is shown to be the best in this system. An es timation of excess molar volumes is also evaluated using a modified He ller equation, which depends on the refractive indexes of the mixtures . Comparison of the predictions by different methods with the experime ntal values of the physical properties has been made.