Question

The osmotic pressure of the solution is given by the relation :
where,
$\pi \text{is osmotic pressure}$
$T\text{is temperature}$
$R\text{is ideal gas constant}$
$n\text{are number of moles}$
$V\text{is volume}$
All quantites are in their SI units

• A. $\pi =\frac{V\times R\times T}{n}$
• B. $\pi =\frac{n\times R\times T}{V}$
• C. $\pi =\frac{V}{n\times R\times T}$
• D. $\pi =\frac{n\times V}{R\times T}$

Answer 1

The correct option is B $\pi =\frac{n\times R\times T}{V}$

Osmotic Pressure
The external pressure which must be applied on the solution of higher concentration side just to stop the process of osmosis.
$P_{ext}$ must be applied on the side that has higher solute concentration.
The osmotic pressure has been found to depend on the concentration of the solution.
$\pi \propto \text{Concentration (Molarity)}$
$\pi \propto T$
$\pi =CRT=\frac{n\times R\times T}{V}$
Since the osmotic pressure is only dependent on solute concentration and not its nature, hence it is a colligative property.
At a particular temperature :