Photosynthesis Experiment
“ Proving that the plants needs Carbon Dioxide”
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 from the previous color, that means the plants doesn’t absorbed carbon dioxide.
Materials:
- - Bromothymol Blue
- - 3 test tubes
- - Test tube rack
- - Pondweed
- - Straw
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.
Result:
At the end of the experiment, there was changes of color in different test tube. Some needs carbon dioxide as its color changes and some didn't need carbon dioxide as the color stay the same.
The first test tube in this picture still contains carbon monoxide and was put down for 2 days to see the changes of color.
Before
AfterAfter 2 days, the color changes into darker green which proves that the plant needs carbon dioxide as it's already been absorbed
The result from the 3 test tubes after 2 days:
Before -> After
