Table of Contents
- 1 Why did the pH of the water surrounding your Elodea change color when placed under a light?
- 2 When the pH is basic the pH indicator we used in the photosynthesis experiment is?
- 3 Why did the tube with elodea change to a light blue?
- 4 How does light affect the rate of photosynthesis?
- 5 Why are carbon fixation test tubes placed under grow lights?
Why did the pH of the water surrounding your Elodea change color when placed under a light?
Why did the solution that contained Elodea maintained in light change from pale yellow to red? Just as the addition of carbon dioxide to a solution increases proton concentration (and therefore, decreases pH), the removal of carbon dioxide from a solution decreases proton concentration (and therefore, increases pH).
When the pH is basic the pH indicator we used in the photosynthesis experiment is?
chemical bromothymol blue
This lab uses the chemical bromothymol blue. This chemical is used as a pH indicator. When the pH is above a 7 (basic) it is blue, but when the pH drops below 7 (acidic) it starts to turn yellow.
Why did the water the elodea was in change color from yellow to pink after photosynthesis was allowed to be carried out for a period of time?
Water plants, such as Elodea, absorb carbon dioxide from the surrounding water and return their gaseous wastes to it. If the carbon dioxide concentration in the water decreases the solution will change to pink. If the carbon dioxide concentration in the water increases the solution will change to yellow.
Why did the tube with elodea change to a light blue?
It absorbed the carbon dioxide (photosynthesis) and the tube turned the blue, Why? carbon dioxide is absorbed from water by the plant in presence of light. The absorption of Co2 from water by the elodea in light is revealed through the change in color of the bromothymol blue from blue to green.
How does light affect the rate of photosynthesis?
These bubbles can be counted and the rate of bubbling can serve as an indication of the rate of photosynthesis. When the light intensity is increased, the rate of bubble production should increase. Decrease the light intensity and the rate of bubbling should decrease.
Which is the control in the phenol red experiment?
The control in this experiment was the test tube containing the phenol red solution, but no elodea plant. This was the control, because there was no contaminant in the solution, and so if any color change occurred within the vial, it could be determined that it was not in relation to the elodea plant.
Why are carbon fixation test tubes placed under grow lights?
Because of this, despite being called light independent, carbon fixation usually only occurs during the daytime, and therefore the test tubes in this procedure needed to be placed under grow lights. Did you see a change in color of the phenol red test tube with no elodea added? Why or why not?