Inactive Tutor answered • 03/26/20
Osmotic pressure is the force caused by water as it passes through a semi-permeable membrane. It works as follows:
Assume you have 2 solutions that are separated by a semi-permeable membrane (a membrane with tiny holes that allows water to pass through but NOT larger particles/solutes). If one solution has a high solute concentration and the other has a low solute concentration, the water will move from the low-concentration solution to the high-concentration solution to balance out the concentrations; effectively this dilutes the high-concentration solution and concentrates the low-concentration solution.The force that the water exerts on the membrane as it moves through the tiny holes is called osmotic pressure.
This is related to diffusion, only diffusion refers to the movement of the solute from high solute concentration to low solute concentration. Thus, EITHER process causes concentration to equalize, but osmotic pressure arises when solute movement is restricted.
