What is the effect of osmolarity on water movement between compartments?
There will be net movement of water to the compartment where the solute concentration is highest...........
Across the membrane separating the compartments, there will be movement of water IN BOTH DIRECTIONS. The rate of movement will be GREATER TOWARDS the side that expresses a solute concentration. That is the less concentrated solution exerts an osmotic pressure.
Of course the membrane separating the solutions are permeable to water but not to salt particles, hence a