Activity : Experimental Investigation - Carbon dioxide is necessary for photosynthesis

Activity : Experimental Investigation - Carbon dioxide is necessary for photosynthesis

1. Take a destarched potted plant. Take a conical flask and put some potassium hydroxide into it. 

2. Potassium hydroxide absorbs the carbon dioxide. 

3. Insert one leaf into this conical flask through a split cork. 

4. Leave the plant in sunlight for few hours. 

5. After few hours take out this leaf from conical flask and remove it from the plant.

6. Take another leaf from the same plant.

7. Test both these leaves for presence of starch.

8. You will observe that the leaf from the conical flask does not turn blue - black while was exposed to atmospheric air turns blue - black. 

9. This shows that carbon dioxide is necessary for photosynthesis.