Question

The osmotic pressure of a solution:

(P) increases with an increase in number of moles of solute.

(Q) decreases with an increase in number of moles of solute.

(R) increases at a higher temperature.

(S) is dependent on the nature of solute.

Which one of the following is correct?

Options

• Only (P) and (Q) are correct.

• Only (P) and (R) are correct.

• Only (P) and (S) are correct.

• Only (Q) and (S) are correct.

Answer 1

Only (P) and (R) are correct.

Explanation:

Osmotic pressure (π) is given by the formula:

π = CRT

Where,

C = Concentration of solute (depends on the number of moles of solute)

R = Gas constant

T = Absolute temperature

(P) Correct: Osmotic pressure increases with an increase in the number of moles of solute due to the rise in concentration.

(Q) Incorrect: Osmotic pressure increases with an increase in the amount of moles of solute, rather than decreasing.

(R) Correct: Osmotic pressure increases with a higher temperature, as seen by the expression where π is directly proportional to T.

(S) Incorrect: Osmotic pressure is a colligative feature, indicating that it is contingent solely upon the quantity of solute particles, irrespective of the solute’s characteristics.