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An experiment for Osmosis by potato osmoscope.Please explain it with a diagram.
AIM:
To demonstrate the principle of osmosis with the help of a living system.

MATERIALS REQUIRED:
Potato, beaker with water and strong sugar solution.

PROCEDURE:
Potato tuber is taken and its one end is cut to make it flat. At the other end of the potato, a cylindrical cavity is made. Strong sugar solution is poured into the cavity of the potato. This initial level is marked with the help of a ball pin. This set up is called potato osmoscope or potato osmometer.
This potato osmoscope is placed in a beaker containing colored water.

OBSERVATION:
After a few hours, the sugar solution rises within the osmoscope and gets colored.

INFERENCE:
The reason for the rise in the sugar solution is osmosis. This movement of water molecules towards the higher concentration solution through a membrane is osmosis. The potato cell membrane acts as the semi-permeable membrane.

Osmosis Using Potato Osmoscope



demonstration of osmosis
  • Peel off the skin of a large sized potato with a scalpel.
  • Cut its one end to make the base flat.
  • Make a hollow cavity in the potato almost up to the bottom.
  • Add sugar solution into the cavity and mark the level by inserting a pin in the wall of the cavity of the tuber.
  • Place the potato in the beaker containing water.
  • After sometime, it will be noticed that the level of solution in the cavity rises. This is due to the phenomenon of osmosis.
  • This experiment demonstrates that living cells of potato act as differentially permeable membrane.
  • Water molecules from a region of their higher concentration (water in the beaker) move into a region of their lower concentration (sugar solution in potato cavity) through the differentially permeable cell membrane of the potato cells.


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