Question

Osmotic pressure of a solution is
A. Greater than the pure solvent
B. Less than the pure solvent
C. Equal to the pure solvent
D. Less than or greater than the pure solvent

Answer 1

Osmotic pressure is the minimum pressure that needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. It is usually defined as the measure of the tendency of a solution to take in a pure solvent by osmosis.

Complete answer:
The concentration is in direct relationship with the osmotic pressure as according to this $\left( {\pi = icRT} \right)$ . Osmotic pressure increases with the increase in concentration. In the above question a solvent is given which is not having any solute yet. So if a solution is formed it will cause the addition of solute into the solvent hence causing an increase in the threshold amount of pressure to oppose or prevent osmosis for example as occurs in a cell. So as to maintain the solution at the same concentration osmotic pressure that is applied should be higher in amount. Increasing the amount of solute will concentrate on the solution and directly lead to an increase in osmotic pressure.

Hence, the correct answer is Option A.

Note: The concentration is actually in direct relationship with the osmotic pressure as according to this $\left( {\pi = icRT} \right)$ equation. Osmotic pressure usually increases with the increase in concentration Osmotic pressure is the basis of filtering (“reverse osmosis”), a process commonly and mostly used in water purification. The water to be purified is placed in a chamber and put under an amount of certain pressure greater than the osmotic pressure exerted by the water and the solutes dissolved in it.