Question

Which of the following colligative property can provide molar mass of proteins (or polymers or colloids) with greatest precision?

Options

• Osmotic pressure

• Elevation of boiling point

• Depression of freezing point

• Relative lowering of vapour pressure

Answer 1

Osmotic pressure

Explanation:

The osmotic pressure method is the best way to determine the molecular masses of polymers. For one thing, other colligative properties have such low values that they cannot be measured accurately, and for another, osmotic pressure measurements can be performed at room temperature and do not require heating, which may change the nature of the polymer.