Question

The best and accurate method for determining osmotic pressure is:
A. Negative pressure method
B. Berkeley and Hartley method
C. Morse and Frazer method
D. Preffer’s method

Answer 1

We need to know that the osmotic pressure is equal to the pressure which should be applied to the solution to resist the movement of fluid while separating the solution and semipermeable membrane from the pure water. Hence, we can say that the osmotic pressure is equal to the pressure applied to the solution. Mainly a solution contains two components and that is solute and solvent. The component which is present in smaller particles is known as solute and the component present in larger particles is known as solvent.

Complete answer:
The negative pressure method is not the best and accurate method for determining osmotic pressure. Hence, option (A) is incorrect.
The Berkeley and Hartley method is a best and accurate method for determining osmotic pressure. Here, an external pressure should be applied on the solution by using a piston. So, the level present in the capillary tube remains stationary and we can record the readings. And by using this method, we can measure the osmotic pressure accurately. Hence, option (B) is correct.
The Morse and Frazer method is not the best and accurate method for determining osmotic pressure. Hence, option (C) is incorrect.
The Preffer’s method is not the best and most accurate method for determining osmotic pressure. Hence, option (D) is incorrect.

Hence, option (B) is correct.

Note:
We need to remember that the Berkeley and Hartley method is the best and accurate method for determining osmotic pressure. Here, by applying the external pressure, it prevents the inflow of water and it will keep the liquid meniscus at the position until it reaches equilibrium. And the excess pressure which is applied to the solution which prevents the inflow of water and it gives the osmotic pressure at a particular temperature.