Photosynthesis

Photosynthesis Dry Lab


Supplies:
Bromothymol blue,
container
aquarium snail
water
elodea
aquarium plant

Procedure:
1. Fill the container with 500Ml Bromothymol Blue (BTB)

2.Mix 500 Ml water into the BTB

3. Put aquarium snail in the BTB

4.add elodea, let sit 1 hour in a well lit room

5.remove the snail and replace it with an aquarium plant.

6. Place in a dark room for 3 hours.

Obsevations:
1.adding water to bromothymolblue is blue-green
-because water mixed with co2 makes carbonic acid, and when mixed with bromothymol blue, it changes to a blue-green color. Because the acid mixes with the neutral BTB to lower the PH.

2.Water plus bromothymol blue plus an aquarium snail turns yellow.
-the snail emits acid and this causes a reaction that lowers the PH of the water changing it to yellow

3. Water plus bromothymol blue plus elodea, an aquarium plant, is blue-green in light.
-green plants photosynthesize in light and respire all the time. The plant takes in all the carbon dioxide returning the water to an almost neutral state.

4. Water plus bromothymol blue plus a snail plus elodea is blue green in light and yellow when in the dark for three hours.
- Carbon dioxide in water produces sugars and oxygen when sunlight is present btb changes to yellow when in acid and back to blue green when returned to neutral PH.

Conclusion:
After a few experiments we found that acid changes the color of BTB by changing the PH, and changes back to the normal color when it is returned to a neutral state. Plant photosynthesize and constantly respire. Furthermore carbon dioxide mixed with water makes carbonic ascid.