Tuesday, December 2, 2008

POTATO OSMOSCOPE

POTATO OSMOSCOPE

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.