Desalination of seawater is done by using reverse osmosis. The pressure applied to the solution is
[amp_mcq option1=”larger than osmotic pressure” option2=”smaller than osmotic pressure” option3=”equal to osmotic pressure” option4=”equal to atmospheric pressure” correct=”option1″]
This question was previously asked in
UPSC CDS-2 – 2017
The correct answer is larger than osmotic pressure.
Osmosis is the spontaneous movement of solvent molecules through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. Osmotic pressure is the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution. Reverse osmosis is a process where a solvent is forced through a semipermeable membrane from a region of high solute concentration to a region of low solute concentration by applying a pressure greater than the osmotic pressure. This is the principle used in desalination to separate pure water from seawater.