Question

Define reverse osmosis in chemistry class 12

Answer 1

Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property, that is driven by chemical potentialdifferences of the solvent, a thermodynamicparameter. Reverse osmosis can remove many types of dissolved and suspended species from water, including bacteria, and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be selective this membrane should not allow large molecules or ions through the pores holes, but should allow smaller components of the solution such as solvent molecules to pass freely.

Answer 2

Hey !!

If a pressure larger than the osmotic pressure is applied to the solution side, the pure solvent (or water) flows out of the solution through the semipermeable membrane. In this way the direction of osmosis is reversed and so the process is called ''REVERSE OSMOSIS''

                             Thus, we can say that reverse osmosis is just opposite to the osmosis when an extra pressure is applied. Reverse osmosis is used in desalination to get pure water from sea water.

Hope it helps you !!