Question

Seawater is desalinated to get fresh water by which of the following methods?

• A. when pressure more than osmotic pressure is applied pure water is squeezed out of seawater by reverse osmosis
• B. when excess pressure is applied on sea water pure water moves in by osmosis
• C. Water moves out from seawater due to osmosis
• D. Salt is precipitated from seawater when kept undisturbed for sometime

Answer 1

Answer: (A)

when pressure more than osmotic pressure is applied pure water is squeezed out of seawater by reverse osmosis

$\ast$ If external pressure applied on solution is more than osmostic pressure then solvent molecules move from solution to solvent and this phenomenon is known as Reverse Osmosis $(R.O.)$.

$\ast$ This process can be used to obtain pure water from sea water.

$\ast$ Pure water is squeezed out of sea water by $R.O.$