Yeast Beasts in Action

Results:

When hydrogen peroxide was added to each solution, it seemed a little lighter. This was because the hydrogen peroxide was a clear substance.

When we put the yeast in the water, it spread out on the top. It didn't really mix in very well until we stirred it. After it was stirred, the mixture was a cloudy tan that had clumps of gooey yeast in it.

All of our mixtures had a starting kPa of 96.88.

The acid solution was soda, and had the greatest activity, because the gas pressure rose the quickest and went the highest. The ending kPa was 104.7. The reaction caused a lot of bubbles to rise to the surface of the solution.

The neutral solution was milk, and actually had the least activity. This makes sense, though it contradicts our hypothesis, because neutral things tend to not get involve

d. It ended with a kPa of 99.7. The reaction produced a thin, foamy layer on top of the milk.

The base solution was antacid. Its reaction occurred faster and had larger kPa than that of the neutral solution, but slower than that of the acid. The reaction created a thick, foamy layer of bubbles above the solution. The ending kPa was 101.79.

Conclusions:

Hypothesis: The acid will produce a stronger reaction that happens quicker than the others. The base reaction will be the slowest and least powerful. The neutral reaction will be between the other two.

We rejected our hypothesis. This was because the neutral reaction had less gas pressure than the base reaction. We were quite surprised by this, but after some thought, we came to the conclusion that it was probably because neutral substances have less to react with. From this experiment, we concluded that acids released the most gas pressure because they have a corrosive nature. The yeast was thus dissolved faster and more thoroughly, releasing more gas. I think the reason we used hydrogen peroxide was because it helped to thin the solutions, and it is a weak acid. From this experiment, we learned that sometimes, comparing data to information on parts of the experiment or to things in real life can help conclusions be made. For instance, my group decided that the neutral substance was the least reactive because neutral items, countries, substances, etc. tend to not get involved/have an effect on a situation. My group encountered no errors. We had a quick, successful experiment.