Abstract:
The total vapour pressure of the systems hydrogen bromide+xenon and hydrogen bromide +
hydrogcn chloride have been measured as a function of composition at 195.42 K. The results have
been used to estimate the excess Gibbs function GE. The volume of mixing J/E has been determined
for each system at 195.42 K. The HBr + Xe system departs considerably from ideal behaviour, while
HBr+HCl is only slightly nonideal. Neither system exhibits an azeotrope at the temperature
studied. These results, together with similar data reported previously for the HCl + Xe system
(J.C.S. Faraday I, 1975, 71, 1372), are compared with theoretical calculations based on perturbation
theory for liquids of nonspherical molecules. Agreement is good for all three systems. The results
show that both dipolar and quadrupolar forces for the 1-IC1 and HBr molecules have a large eifect
on the phase diagram, while other types of anisotropic intermolecular forces (overlap, dispersion,
induction) appear to have a considerably smaller effect.
