Photosynthesis Experiment : Carbon Dioxide

Photosynthesis Experiment

“ Proving that the plants needs Carbon Dioxide”

Materials:

-       Bromothymol Blue

-       3 test tubes

-       Test tube rack

-       Pondweed

-       Straw

Hypothesis

The result of this experiment is the change of color in the Bromothymol Blue. If the color of the solution changes to dark green or dark blue, it shows that the pondweed has absorbed carbon dioxide, which proves that the plant needs carbon dioxide in photosynthesis. If the color of the solution doesn’t change, that means the plants doesn’t absorbed carbon dioxide.

Procedure:

1.     Cut the pondweed into 3 small parts, all on similar lengths

2.     Set aside the pondweed and prepare the Bromothymol Blue

3.     Fill ¼ of the test tube with Bromothymol blue and add water until it fulfill half of the test tube

4.     Put the straw inside the test tube and slowly blows from your mouth, this will trigger the change of color to yellow green. Be very careful to not inhale the solution

5.     Afterwards, take out the straw and slowly drop the pondweed to the solution

6.     Put the three test tubes on the test tube rack and see the color changes.

Noted that the test tubes are put in the same condition, in this case under the sun or the light.

Results and Comparison

1. The solution when it was first put bromothymol blue and water with the pondweed. Solution still has the carbon monoxide

 2. After being left for 2 days, in the shaded but still can obtained sunlight

3. Comparison between the first solution ( when it still has the carbon dioxide) and the second solution ( when the plant has already absorb the carbon dioxide in the solution)

First Solution

Second Solution