Intermolecular associations in liquid systems of non-polar and slightly polar compounds were studied through excess molar volumes, and excess dielectric properties for mixtures of carbon tetrachloride with benzene, toluene and p-xylene. These excess properties were calculated from measurements of density, static permittivity and refractive index over the whole range of concentrations, at 298.15K. The values of the excess dielectric properties for these mixtures were fitted in two different ways, one through least squares using the Redlich-Kister equation and the other using a model developed to explain deviations from ideality. The first fit was found to be descriptive while the second gave the equilibrium constant values for the interaction products actually formed in the mixtures and the respective electronic polarizabilities and dipole moments, indicating the existence of interaction products.