Some of the things that I observed was that for the soda, nothing extreme happened, like
I thought it would. The pressure started out by only changing a range from .1 to .2, so it
was not major. But all of a sudden the pressure changed, and it went up about one. Towards
the end of the testing session, there were bubbles starting to form in the soda. Maybe from the
building pressure. For the stomach antacid, the mixture remained the same, it was foggy
hydrogen peroxide. After we completed the test, the mixture became very bubbly and it was
stirring around. There was also a little amount of foam clinging on the sides of the glass testing
tube. The pressure for this was 100.70.
The one with the greatest yeast activity and pressure was the Diet Coke soda, which had the pressure of 102.7. I think that the carbonation in the soda had something to do with the pressure. Also the carbon dioxide was released inside, and it was trying the find a way to escape. The test that had to slowest yeast activity and pressure was the slim milk. The skim milk pressure was 100.58. Milk has a pH around 6.4 to 6.8, so it is not actually neutral. The soft drink has a pH 3.0 or lower and the stomach antacid has increased pH in your stomach. I did some research on hydrogen peroxide. I found out that it was a oxidizer, that it commonly found in bleach. Bleach, on the pH scale, is one of the most basic, at 12.5. Pure hydrogen peroxide has a pH of 6.2, which will make it a weak acid. So, it really depends on what it is mixed with it. So the basic and the acid will have a different reaction than a acid and acid reaction/pressure.
Some things that I concluded from my results of the experiment was that there the reaction between acids and bases are different, but they can both create very similar pressures, because they were so close. Some of things that went wrong is the experiment was turning the Diet Coke test. After we had added the two drops of yeast, we shook the mixture, but we did not start the test right after. This could have released some of the carbon dioxide, that could contributed to the pressure. Another action was that we had to retest a test, because the data was not collecting any of the pressure.
What can you conclude from the results of your experiment?