Question

Three cylinders of potato were carefully dried on blotting paper and weighed. Each piece weighed 3 grams. Each one was placed in the beaker as shown below:

Answer the following questions:

1. After 48 hours, which potato cylinder would be the heaviest?
2. The movement of which substance is mainly responsible for the weight change in the potato cylinders?
3. Name and define the process which is responsible for the movement of the substance mentioned in answer (b).
4. Write specific names of the processes which occur in beakers B and C. [kinds of processes defined in answer (c)].
5. Would there be any difference in the weight of the potato cylinder in beaker A after 48 hours? Give reason.

Answer 1

1. Cylinder B will be the heaviest when it is stored in distilled water for 48 hours. Distilled water will function as a hypotonic solution for the potato cylinder. Through the process of endosmosis, the potato cylinder will absorb distilled water from the beaker, resulting in an increase in its weight.
2. When the potato cube is placed in water, the water starts entering the cube, thus increasing its size and due to the pressure of the cell contents on the cell wall, there appears to be firmness in the wall of the cube.
3. The physical process involved in it is Osmosis.
   Osmosis: Water diffusion from a dilute to a concentrated solution across a differentially selectively permeable membrane.
4. Beaker B - Endosmosis
   Beaker C - Exosmosis
5. Because the potato cylinder is maintained in air, its weight will remain constant in beaker A. There is no significant change in the weight of the potato cylinder in beaker A, as there is no movement of water between the potato cylinder and beaker.