Photosynthesis Lab

Materials:
Bromoythmol Blue
aquarium snail
Water
Elodea
Aquarium Plant
container

Procedure:
1. Fill a container with 500 milliliters of bromothymol blue (BTB)

2. Mix 500 milliliters of water into the BTB

3. Now put an aquarium snail into the BTB

4. Add elodea to the water, let sit for 1 hour in a well lit room, and then notice the color of the BTB.

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

6. Let sit for 1 hour in a well lit room, then place it in a dark room with no light for 3 hours. Notice the color of the BTB.

Observations:
-Adding water to bromothymol blue is a blue-green.
Because CO2 mixed with water makes carbonic acid, and mixed with bromothymol blue, it changes to a blue-green color, because the acid mixes with the neutral Bromothymol blue, to change the pH to a lower number.

-If you add an aquarium snail to the blue-green water, the water turns yellow.
The acid from the snail changes the Ph to a lower number, and the blue-green liquid changes yellow when reacting with an acid.

-If you add water and elodea and an aquarium plant to bromothymol blue, it looks blue green in light
Green plants photosynthesis in light and always respire, therefore the aquarium plant takes in the carbon dioxide keeping closer to a neutral pH level.

-If you add water, elodea, and an aquarium snail to bromothymol blue, it looks blue green in light, but yellow in the dark.
Carbon dioxide and water produces sugar and oxygen when chlorophyll and sunlight are present, and when Bromothymol blue reacts with an acid it turns yellow, and changes back to blue green when it gets back to a normal pH Level.

Conclusion:
So after we experimented, we discovered that acidic substances change bromothymol blue yellow by changing the pH level and if the pH level is returned to a neutral number, then the color changes back to a blue green shade. We have discovered that plants photosynthesis in light, and constantly respire. Also, that carbon dioxide mixed with water, produces a carbonic acid.