FT-IR spectroscopy is used to directly measure the composition of the sorbed phase on a charged, expandable organo-montmorillonite placed into contact with binary solvent solutions. Experimental data are compared with thermodynamic computations of the sorbed phase composition. The theoretical treatment, developed in part 1, examines the extent of partitioning due to electrical charging of the clay-water interface which is in addition to any partitioning that might result from purely chemical differences between the interlayer environment of layered aluminosilicate clay minerals and an external solution. Provided the extent of partitioning is expected to be large, as it is for the acetone-toluene system, the agreement between theory and experiment is very good. On the other hand, as the predicted extent of partitioning becomes smaller, the agreement between theory and experiment degrades. In addition to composition measurements, the magnitude of the interfacial electric field is characterized by examination of the carbonyl stretching frequency of acetone, which is common to all three solvent combinations studied. As the component of smaller dielectric constant is displaced, the carbonyl stretching frequency is observed to rise. This is expected since an increased dielectric constant will reduce the electric field and thereby favor the nonpolar form of acetone with its higher stretching frequency. The implications of our results to electrical double-layer theory, which treats the dielectric constant as spatially fixed, are briefly discussed.