Which of the following is NOT a colligative property of a solution?

• A. Freezing point depression
• B. Boiling point elevation
• C. Color
• D. Osmotic pressure

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what colligative properties are. Colligative properties depend on the number of solute particles in a solution, not on their identity. These properties include freezing point depression, boiling point elevation, vapor pressure lowering, and osmotic pressure.
2. Step 2: Review each option given: Freezing point depression, boiling point elevation, and osmotic pressure are all classic colligative properties because they depend on solute particle concentration.
3. Step 3: Consider the option 'Color'. Color is a physical property related to the nature of the solute or solvent molecules and how they absorb or reflect light, not the number of particles.
4. Step 4: Conclude that since color depends on the chemical identity and not on the number of dissolved particles, it is NOT a colligative property.
5. Step 5: Therefore, the correct answer is 'Color' because it does not depend on the concentration of solute particles in the solution.