Abstract
In a liquid mixture A-B, the fractions of the contact between the like molecules and that between the unlike molecules to the total contact are represented by XA2, XB2, and XAXB, XBXA respectively, where x denotes the mole fraction.
In vapor-liquid equilibrium, at the part of XA2, XB2, in the liquid phase exert the vapor pressures corresponding to their pure liquids A and B, while at the part of XAXB, XBXA the different vapor pressure from their pure state appears. Thus, the total pressure is shown to be the arithmetic sum of the respective vapor pressures and the equations for the prediction of the vapor composition based on the partial fraction give fairly good agreement with the data shown in the literatures.
Other physical properties than vapor pressure in the liquid mixture also endorse the coexistence of "pure state" and "mixed state".
