Question

Define colligative property. Which colligative property is preferred for the molar mass determination of macromolecules?

Hint:

- Colligative properties depend on the number of solute particles, not their identity. - Osmotic pressure is preferred for macromolecules due to its high sensitivity and suitability at room temperature.

Answer 1

A colligative property depends only on the number of solute particles and not on their nature. Osmotic pressure is the preferred colligative property for molar mass determination of macromolecules. 
Step 1: Definition of Colligative Property Colligative properties are solution properties that depend only on the concentration of solute particles and not on their identity. 
Examples of Colligative Properties: - Relative lowering of vapour pressure - Boiling point elevation - Freezing point depression - Osmotic pressure

Step 2: Why Osmotic Pressure is Preferred for Macromolecules? - Osmotic pressure (\( \pi = CRT \)) is highly sensitive to small concentrations, making it ideal for determining the molar mass of macromolecules like proteins and polymers. - Unlike boiling point elevation or freezing point depression, osmotic pressure is measurable at room temperature, preventing thermal degradation of macromolecules.