Colligative properties are applicable to:

dilute solution

The correct answer is Option (1) → dilute solution

Core Concept

Colligative properties depend only on the number of solute particles and are valid for dilute solutions.

colligative properties are those properties of solutions that depend on the ratio of the number of solute particles to the number of solvent particles in a solution, and not on the nature of the chemical species present.

Colligative properties of a solution include relative lowering of vapour pressure, elevation of boiling point, depression of freezing point, and osmotic pressure.

Detailed Explanation

Option 1: Dilute solution

Colligative properties like lowering of vapour pressure, elevation of boiling point, depression of freezing point and osmotic pressure are accurately applicable only when solutions are dilute.

In dilute solutions, solute particles behave ideally.

Option 2: Solid solutions

Colligative properties apply to liquid solutions mainly, not solid phase systems.

Option 3: Concentrated solutions

In concentrated solutions, solute-solute interactions become significant.

Hence deviations from ideal behavior occur.

Colligative laws no longer apply accurately.

Option 4: Only aqueous solution

Colligative properties are not restricted to water.

They apply to any solvent.