What is reverse osmosis? What is this process used for?

Dear student.

Osmosis is the net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in order to equalize the solute concentrations on the two sides.

However, if the pressure applied on concentrated solution is greater than its osmotic pressure, then the direction of osmosis is reversed i.e., the solvent starts passing from solution with high concentration of solute to solution with low concentration of solute. The phenomenon is called reverse osmosis.

This process is widely used in the desalination of sea water.

Regards.