VAPOR-LIQUID EQUILIBRIA OF BINARY SYSTEMS OF WATER WITH METHANOL AND ETHANOL AT EXTREME DILUTION OF ALCOHOLS

A new method for determining vapor-liquid equilibrium data for binary systems, including measurements at concentrations of one of the components in the parts per million range, is described. The method is based on the use of radioactive tracers, as the component in low concentration is added partly in an isotopic form. The method has been tried at 760 mm. of Hg pressure for two systems, methanolwater and ethanol-water, at low concentrations of the alcohols. Separation factors and activity coefficients for the alcohols at extreme dilution are given. The data have been tested for thermodynamic consistency and proved consistent. © 1969, American Chemical Society. All rights reserved.