Question

______ is a semi-permeable membrane.

• A. Copper ferrocyanide
• B. Copper ferricyanide
• C. Copper sulphate
• D. Potassium ferrocyanide

Answer 1

The correct option is A Copper ferrocyanide

The synthetic semipermeable membrane used in Berkeley-Hartley method is Copper Ferrocyanide. Berkeley-Hartley method It is used to measure the osmotic pressure of two solutions of different concentration separated by semi-permeable membrane procedure: in this method, there are two cylinders one covering other and separated by a semipermeable membrane as shown in the figure. On end is connected by theisel funnel called and another end by the capillary tube to measure the height of solution filled in the inner cylinder. The upper layer of the cylinder is connected with the piston and pressure gauge apparatus. In this outer cylinder, the concentrate solution is filled while in the inner cylinder dilute solution like water is filled. When osmosis takes place the height in capillary tube decreases while the piston moves in the upward direction. In order to maintain, the same height on the capillary tube, the pressure over piston is applied. The minimum pressure which is applied to maintain the same height in the capillary tube is measured by pressure called which is called osmotic pressure.

It is ${Cu}_{2}Fe{\left(CN\right)}_6$ molecule in the gelatinous state to work as semipermeable in nature.

Hence, the correct option is $\text{A}$