A head-space gas chromatographic technique has been used to determine vapou
r/liquid equilibria at 298.15 K of binary mixtures of di-n-butyl ether plus
an organic compound (hexane, octane, diethyl ether, tetrahydrofuran, propy
lamine, butylamine, propanone, cyclopentanone, methanol, butan-1-ol, aceton
itrile). Excess molar Gibbs energies, G(E), for the systems investigated ha
ve been obtained by a least-squares treatment of equilibrium data. Mixtures
with hexane, octane and diethyl ether revealed an almost ideal behaviour.
Other systems showed positive deviations, which increase with the polarity
of the second component. Dibutyl ether+butanol and +cyclopentanone revealed
the formation of azeotropic compositions. The Kirkwood-Buff integrals over
the entire composition range have been calculated from the composition dep
endence of G(E), and briefly discussed.