| Abstract
| - Total vapor pressures for liquid mixtures of xenon + ethane at 161.40 and 182.34 K and of xenon + propaneat 161.40, 182.34, and 195.49 K have been measured. Both systems show negative deviations from Raoult'slaw at all temperatures. The corresponding excess molar Gibbs energies () have been calculated from thevapor pressure results. Liquid molar volumes have also been measured for both mixtures at 161.40 K, leadingto calculated excess molar volumes () which are negative in all cases. Additionally, the excess molarenthalpies () for the xenon + ethane system have been determined directly using a batch calorimeter andfound to be negative. Xenon + ethane is thus the simplest system which exhibits negative values for all threemajor excess molar functions. The results were interpreted using the statistical associating fluid theory forpotentials of variable attractive range (SAFT-VR). The theory is able to predict the phase behavior of bothsystems in close agreement with the experimental results. It was found that the xenon + n-alkane mixturesobey Lorentz−Berthelot combining rules, so that no unlike interaction parameters are fitted to experimentalmixture data. The theory is therefore totally predictive. It was also found that the parameters calculated forxenon using this model lie within the average values of the parameters obtained for the n-alkanes. This impliesthat, in contrast with the anomalous behavior of methane, xenon can be treated as the first member of then-alkane family. Furthermore, the xenon + n-alkane mixtures can be thought as a particular case of mixturesof n-alkanes.
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