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