In this work vapor pressures and
activity coefficients at infinite
dilution (γ
i
∞) were measured using a newly commissioned
ebulliometer (a noninvasive phase equilibrium measurement device),
that has been modified with the view to improve the precision and
measurement time of the apparatus, as well as the effects of superheating.
The systems considered were C2–C4 n-alcohols
with three different classes of solvents (ester, n-alkane, ketone), namely, (ethanol/propan-1-ol/butan-1-ol) + (ethyl
acetate, n-octane, butan-2-one). The temperature
range considered was T = (303.15 to 343.15) K, which
corresponded to subatmospheric conditions. The γ
i
∞ data were correlated empirically for temperature using standard
procedures. A portion of the γ
i
∞ data measured are available
in the literature and compared well with an acceptable correlation
for this type of data, for the majority of the systems considered.
The data were also compared to extrapolations of γ
i
∞ from reliable vapor–liquid equilibrium data. Vapor–liquid
equilibrium predictions were also made from the limiting activity
coefficients and established that the presence of azeotropes and their
temperature dependence were correlated from the measured γ
i
∞.