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.



1 comment:

  1. You explain the set up and lab well, but forget to discuss the enzyme. Where was the enzyme and how did it contribute to the reaction? Also, find a way to include a data table. I love the pictures.

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