Explain reverse osmosis and purification of water.

Explanation

The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomen on is called reverse osmosis.

The pressure required for the reverse osmosisis quite high . A workable porous membrane is a film of cellulose acetate placed over a suitale support. Cellulose acetate is permeable to water but impermeable to impurities and ions present in sea water. These days many countries used esalination plants to meet their potable water requirements.