What is osmotic pressure and why reverse osmotic pressure can be used to purify water?
Diffusion of solvent molecules across semi-permeable membrane results in the osmotic pressure, and keep this in mind as you describe osmotic pressure. The osmotic pressure is similar to pressure of gas in that the molecules or ions in a solution are similar to the molecules in a gas. Thus, by applying a high pressure in concentrated solution, the solvent can be forced to diffuse in a reverse direction. Keep this in mind as you explore the website to understand the reverse osmosis process for purification of water.