Question

Which one of the following, measures osmotic potential of a solution by measuring its freezing point?

• A. Potato osmometer
• B. Cryoscopic osmometer
• C. Potometer
• D. All of the above

Answer 1

The correct option is B Cryoscopic osmometer

Potato osmometer is used to demonstrate osmosis in the laboratory. "Cryo" prefix denotes low temperature. The cryoscopic osmometer measures the osmotic potential of a solution by measuring its freezing point. Solutions have colligative properties that collectively depend on the number of dissolved particles. One of the colligative properties of solutions is the decrease in the freezing point as the solute concentration increases. The decrease in freezing point will give a measure of solute concentration in the solution. Once we know the solute concentration in the solution, the osmotic potential can be easily worked out using the formula -CRT, where C is the concentration, R the universal gas constant and T the absolute temperature.

So, the correct answer is 'Cryoscopic osmometer'