. Toluene Acetone/Water
Compound X *
Compound Y *
If you had compound X in toluene while having compound Y in acetone/water, would you need to separate them?
This "problem" applies to a solid-solid, solid-liquid, or liquid-liquid mixture that can be partitioned between two nearly immiscible phases.
Toluene is miscible with acetone. Acetone is miscible with water. Acetone and water when mixed together experience strong dipole-dipole interactions that cannot be overcome by toluene. Hence if you take your mixture, then dump it into a separatory funnel containing the three solvent system, compound X will be in the upper phase (toluene, d = 0.87) while compound Y will be in the lower phase (acetone-water, d = 0.93 for 1:1 mixture 20C, J. Chem. Eng. 1965, 10(4), 330-334.). Be prepared for a really nasty emulsion with this one. In principle this works, however I wouldn't want to do it in the lab.
When it comes to something like this, it's easier to concentrate on images rather than words. The words sometimes lead to confusion.