Which of the following is a colligative property?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Osmotic pressure
Colligative properties depend only on the number of solute particles, not on their nature. The four are relative lowering of vapour pressure, elevation of boiling point, depression of freezing point and osmotic pressure. Of the given options, only osmotic pressure is itself one of these.
Why the other options are incorrect
Option (1) Vapour pressure — Incorrect. The vapour pressure of a solution depends on the nature of the solvent; the colligative property is the relative lowering of vapour pressure.
Option (3) Freezing point — Incorrect. The freezing point itself depends on the solvent; the colligative property is the depression of freezing point.
Option (4) Boiling point — Incorrect. The colligative property is the elevation of boiling point, not the boiling point itself.
NCERT (2026-27 edition):
Colligative Properties and Determination of Molar Mass
