Question

prove by an experiment how co2 is liberated during respiration

Answer 1

Procedure:

1. Take the conical flask and place some germinating gram or pea seeds in it.

2. Insert the shorter end of the glass tube through the hole in the cork and fix it on the conical flask.

3. Before fixing the cork, hang a test tube containing KOH solution inside the conical flask with the help of a thread.

4. Take coloured water in the beaker and keep the longer end of the glass tube dipped inside it.

5. Make the conical flask airtight by applying Vaseline on its rim.

6. Note the initial level of water in the tube.

7. Observe and note the rise in the water level after an hour, without disturbing the apparatus.

OBSERVATION: Water rises up in the bent tube.

RESULT:
The rise in the level of water indicates that CO2 is produced by germinating seeds during respiration. Actually, the germinating seeds respire and produce CO2, which is absorbed by KOH solution. This creates a vacuum in the conical flask. The air present in the bent glass tube moves into the conical flask. This pulls the water in the bent tube further up.

Answer 2

During the process of cellular respiration, carbon dioxide is given off as a waste product. This carbon dioxide can be used by photosynthesizing cells to form new carbohydrates. Also in the process of cellular respiration, oxygen gas is required to serve as an acceptor of electrons.