Which of the following does not come under the category of colligative properties?

Depression in Freezing point of the solute

The correct answer is Option (4) → Depression in Freezing point of the solute

Colligative properties depend only on the number of solute particles, not on their nature. Relative lowering of vapor pressure, osmotic pressure, and depression in freezing point of the solvent are standard colligative properties. These properties occur due to the effect of solute particles on the solvent's physical properties. Freezing point depression always refers to the solvent, not the solute.