stubbs

Hey This is my first post so i'm not sure if this is the appropriate section to ask this question so please let me know if not. Basically i'm studying medicine and specifically the kidneys currently and have managed to forget lots of my basic school bio knowledge so was hoping someone could help me out. My question is this: what happens if you have a membrane separating 2 solutions of different osmolarities and the membrane is only permeable to solute "X" (not even water). if... solute X is in high concentration on one side relative to the other BUT the osmolarity of the solution on the other side is higher, what happens? Any help is much appreciated.