Photosynthesis Lab Procedure

So for this lab, the whole thing basically worked backwards. We got results and data, but had to write the procedure and conclusion from that data. Without actually doing the experiment.

Materials:

• Distilled Water
• Bromothymol Blue (BTB)
• Aquariums Snails
• Elodeas (the plant things)
• One Test Tube 
• 200 ml Beakers
• Light
• Dark Space (closet maybe?)

Procedure:

1. In a test tube, mix 25ml of water with 10 drops of BTB (or until it turns blue), record your observations.
2.  In a beaker, mix 100ml of water with 20 drops of BTB (or until it turns blue), add in an aquarium snail. Let sit in light over night.  Record your observations.
3. In a beaker, mix 100ml of water with 20 drops of BTB (or until it turns blue), add in a single eloda, Let sit in light over night. Record your observations.
4. In a beaker, Mix 100ml of water with 20 drops of BTB (or until it turns blue), add in a single eloda and a aquarium snail. Let sit over night in the light. Record your observations. 
5. Repeat number four letting it sit in the dark for 3 hours. Record your observations. 

Observations (and Conclusions):

1. Water plus BTB is blue-green.
1. BTB stays blue-green in a neutral pH, because distilled water is perfectly neutral, it stays blue-green.
2. Water plus BTB plus a snail turns yellow.
1. Animals respire (put CO2 out), so because CO2 plus water makes carbonic acid, then because the BTB turns yellow in acid, the carbonic acid turns it all yellow.
3. Water plus BTB plus Eloda is blue green in light.
1. The plant respires and produces CO2, but then uses that CO2 for photosynthesis.
4. Water plus BTB plus snail plus eloda is blue green in light, and yelow when left in the dark for three hours
1. The solution is green in the light because the plant does photosynthesis with the CO2 (from the snail AND the plant) preventing carbonic acid.
2. In the dark the plant does not photosynthesize so the CO2 from the snail and the pant from carbonic acid in the water.