Dioxide Chlorophyll
6CO2 + 6H2O C6H12O6 + 6O2
Apparatus:
Beaker
Spatula
Stopwatch
Bulldog Clips
Canadian Pond Weed
Sodium Hydrogen Carbonate
Angle Poised Lamp – 60 Watts
Prediction
I predict that the closer the lamp (bulb) to the pond weed the higher the number of oxygen bubbles given off, as the light source is moved closer the more intense light speeds up the rate of photosynthesis.
Plan
To do this experiment we had to get a beaker full with water and some Canadian pond weed weighted down with bulldog clips, so the entire weed is covered in water. We had an angle poised lamp with a 60w bulb shining on the beaker, we measured the distances from the pond weed to the bulb every time, then counted the number of oxygen bubbles given off. To make this a fair experiment we had to mark a point on the beaker and counted every bubble that rose above that point.
Method
The variables we can control are the background (room) lighting, because if the surroundings were darker in some and not in others the number of oxygen bubbles that are given off may change. To speed up the rate of photosynthesis we added a spatula of Sodium Hydrogen Carbonate (Bicarbonate of Soda).
Safety
To make this experiment safe, we will have to tuck in chairs and make sure that coats and bags are tucked away because you may trip and fall spilling or smashing a beaker, or if you spill something on your desk you don’t have to get wet just move out of the way. We don’t have to wear any safety goggles, as this experiment doesn’t involve any chemicals in risk of coming into contact with our eyes.
Results
Conclusion
In conclusion to my results, I can see that I have proved my prediction right that the higher the intensity of light, the quicker the rate of photosynthesis. I can see this from my line graph that more bubbles rose when the bulb was closer, than when the bulb was further away.
Evaluation
I think that I could have done better if I got a first set of results that were correct, but instead our teacher gave us a set of more consistent results so it wouldn’t mess up our graphs or conclusions. Our results weren’t consistent because it was hard to tell how many bubbles rose at a time, because the bubbles were stuck to the leaf and some of them were too small to see. We also could have sped up the rate of photosynthesis by increasing the carbon dioxide, as it needs this to do the process.
Scott Swanson
10DJG