Q:

(a)- describe the Berkley-Hartley method to measure osmotic pressure along with its limitations???

(b)- dissolution of ammonium chloride is endothermic process.What is the effect of temperature on its solubility?

plsss solve

 

The figure shows the apparatus for Berkley-Hartley method to measure osmotic pressure.The solvent and solution are separated by a semi permeable membrane consisting of copper ferrocyanide. To prevent the flow of solvent molecules into the solution, a hydrostatic pressure is applied to the solution.The level of solvent in the capillary tube tend to decrease due to osmosis which is prevented by applying pressure.The pressure at which the level of solvent in the capillary tube remains stationary is known as the osmotic pressure of the solution.

Limitations:

If the membrane used is slightly leaky, the solvent molecules would easily enter the solution.To prevent the solvent molecules entering in the solution, a large amount of pressure will have to be applied.Thus, the osmotic pressure will have an increased value.

 2) According to Le Chatelier's principle, an endothermic reaction is favoured by an increase in temperature.Since the dissolution of ammonium chloride is endothermic process, therefore, increase in temperature will increase the solubility of ammonium chloride and vice versa.