Help a struggling biology student?? (Diffusion)

An animal cell with a high concentration of molecule X is put in a solution with a lower concentration of melecule . If X can pass through the membrane, which way will it move? If the membrane is impermeable to X, what will happen? Explain your answers.

Ok im thinking.... if x can pass through the plasma membrane then it will and try to make the whole thing isotonic or (=) but if it can't... it will draw in water and try to dilute X. Also is Na+ moving to a higher concentration facilitated diffusion, or simple diffusion?

yeah your on target. Diffusion will move from the hypertonic solution to the hypotonic solution. If x cannot pass throught the membrane the solvent -undoubtedly water- will move instead.

edit: when the water moves its called osmosis

Thanks man I appreciate it, im tryin to get some of these questions done on a wksht and dont have my book to check my answers with.

sure. nice avatar btw