Sunday, August 28, 2011

Oxygen Lab.

On Friday the 26th of August we did a lab involving yeast, 3% hydrogen peroxide (H2O2), and water. We were measuring the the enzyme activity using these products above. We also used some equipment such as a graduated cylinder, a large rubber container, about a ten inch plastic tube, parafilm, a tube with a lid and a ring-stand. With all of this materials we were testing the change in water level as the Hydrogen Peroxide, and yeast caused a chemical reaction producing oxygen.

Set Up
We began with filling our large rubber container with water. We filled it about three-quarters of the way full. After that we sat our container in the base of the ring stand and began then we placed the graduated cylinder and filled it full of water. When it was full we turn it upside down where the open end of the graduated cylinder was still in the water not releasing any of the water while still having space under it to be able to insert the tube into the cylinder.. We then attached the clamps around the graduated cylinder. After that we place one end of the tube in the cylinder and the other end through the hole of the container with the lid. Our hole as a little large to prevent oxygen being released through the creases we place parafilm around the tube and the lid.


Experiment
Now that we have the experiment set up we shall begin. We began by putting 100 ml of Hydrogen Peroxide (H2O2) in the container. As soon as we were ready we placed 10 ml of a yeast and water mixture. We capped it then placed it into the water. We let the chemical reaction take place for five minutes. and at the end of five minutes we recorded the change of water level in our graduated cylinder. We performed three trials. One with 10 ml of the yeast and water mixture, one with 5 ml, and one with 2.5 ml. When this experiment was performed the yeast and the Hydrogen would chemically react and produce a chemical reaction creating/releasing oxygen. As the oxygen was released it would rise to the top of the graduated cylinder through the tube and change the water level inside the graduated cylinder. When we performed these we came to the conclusion that the less of the yeast mixture we used, the gas level decreased. Due to that, the change in water level decreased.

Conclusion
When we finished our experiment we came to a conclusion that the less yeast you use to react with Hydrogen Peroxide the less of a chemical reaction there is, there for a lower gas level which produces a small change in the water level.

Below are some picture from our experiment.



Sunday, August 14, 2011

Rollie Pollie (pillbug) Lab

  With this lab me and my group tested how the pillbugs would react to a changing enviorment. In our project we seperated the soil out evenly with an even amount of pill bugs on each side of the choice chamber. On one side of the choice chamber we wet one of the filters (group A) and the other was dry. After we did that we every two minutes for twenty minutes we counted how many pillbugs were in each chamber. After every time interval we noticed that our results were inconsistent. We believe that this could have been affected by lack of time and the stress levels of the pill bugs.  Below are the results of our experiment.


 Time (minutes)
2 min
 4 min
 6 min 
8 min
10 min
12 min
14 min
16 min
18 min
20 min
# of bugs in Chamber "A" (wet)
8
9
5
6
6
5
3
4
4
4
# of bugs in Chamber "B: (dry)
6
5
9
8
8
9
11
10
10
10