Answer: Osmotic pressure.
- A Colour of solution
- B Viscosity
- C Osmotic pressure
- D Density
Correct answer: C. Osmotic pressure
Explanation: Colligative properties (osmotic pressure, boiling point elevation, etc.) depend on number of solute particles, not their nature.
Adding a non-volatile solute lowers the solvent's vapour pressure at every temperature, which is the root cause behind all four colligative properties: it shifts the freezing point down and the boiling point up.
Concept context
Learn how substances dissolve and form mixtures. Covers concentration terms, colligative properties (boiling point elevation, freezing point depression, osmotic pressure), and ideal vs non-ideal solution behaviour.