EXCESS PARTIAL MOLAR FREE-ENERGIES, ENTHALPIES, AND ENTROPIES IN 2-BUTANONE-H2O MIXTURES - SOLUTE SOLUTE INTERACTIONS

The excess partial molar enthalpies, H(m)E(i), in 2-butanone (BUT)-H2O mixtures were measured at 4.20, 20.00, and 25.00-degrees-C (i = BUT or H2O). The vapor pressures were also measured by a static method at 20.00 and 25.00-degrees-C. From the latter data, the partial pressures and hence the excess partial molar Gibbs free energies, G(m)E(i), were calculated by the method. The excess partial molar entropies, S(m)E(i), were then calculated at 20.00 and 25.00-degrees-C. From the composition derivatives of these partial molar quantities, the nature of the solute-solute interactions was discussed in relation to the global information about the mixture: existence of phase separation, the way in which the phase boundary slants, and existence of azeotropy and addition compound.