demonstrate that we breathe out CO2.Requirements, Procedure, Observation, Conclusion
Answers
Answer:
procedure
1. Using a spatula, place about 30 germinating bean seeds in a conical flask.
2. Pour 4ml of potassium hydroxide (KOH) solution into a measuring cylinder.
3. Transfer the KOH solution from the measuring cylinder into a small test tube.
4. Tie a cotton thread around the neck of the test tube.
5. Suspend the test tube in the conical flask above the germinating seeds.
6. Close the mouth of the conical flask with a cork.
7. Insert one end of a delivery tube into the conical flask through the cork and dip the other in a beaker containing water.
8.Take some Vaseline with your finger and apply this on the cork to make the apparatus air tight.
9. Keep the apparatus undisturbed for two hours.
Observation:
After two hours, you will see that the level of water has risen in the delivery tube at the end dipped in the beaker of water.
conclusion:
The germinating seeds in the conical flask release CO2 during respiration, which is absorbed by the KOH solution kept in the small test tube. This creates a partial vacuum in the flask that forces the water up the delivery tube. Thus, it proves that germinating seeds produce carbon dioxide during respiration.