Which statement best defines colligative properties?

• A. Properties of solutions that depend primarily on the molar mass and chemical identity of the solute
• B. Properties of solutions that depend only on the number of dissolved particles (solute concentration), not on the chemical identity of the solute
• C. Properties that describe how a solute changes the rate at which a reaction reaches equilibrium in solution
• D. Properties of pure substances that depend on intermolecular forces in the pure liquid or solid, not on dissolved solutes

Answer: (B)

Verified step by step guidance

1. Understand that colligative properties are characteristics of solutions that depend on the presence of solute particles, but not on what those particles actually are chemically.
2. Recognize that these properties depend only on the number of dissolved particles, which means they are influenced by solute concentration rather than the solute's molar mass or chemical identity.
3. Recall common colligative properties such as boiling point elevation, freezing point depression, vapor pressure lowering, and osmotic pressure, all of which change based on the quantity of solute particles.
4. Eliminate options that mention dependence on molar mass, chemical identity, reaction rates, or properties of pure substances, as these do not align with the definition of colligative properties.
5. Conclude that the best definition is: 'Properties of solutions that depend only on the number of dissolved particles (solute concentration), not on the chemical identity of the solute.'