Next came setting up the lab. Each group received and set up with a small glass bottle (including a rubber cork with a long rubber tube), a tall graduate glass cylinder, an arm to hold said graduated cylinder, a few smaller graduated glass cylinders, a thermometer, and a rubber tub. Before the groups were permitted to delve into the experiment, a control for the rate of the chemical reaction needed to be established. Each group then filled their rubber tub almost to the top with water which was allowed to sit until the water was about room temperature (about 22 °C). Once the water was about room temperature, everyone filled the large graduated glass cylinder completely with water and slid it upside-down into the arm to hold the lip just below the surface of the water. Sam then filled one small graduated cylinder with 5 mL of yeast and Bridgette filled the other with 5 mL of hydrogen peroxide. The yeast was poured into the small glass bottle, and the hydrogen peroxide was added second. The cap with the rubber tube was placed on quickly, and it was placed underwater just as quickly. The rubber tube coming from the cork was then slid up into the tall graduated glass cylinder, and Bridgette began timing. Every twenty seconds across 5 minutes, Sam would write down how much oxygen gas had displaced the water (see "Control " graph and for the results).
Now that a control had been established, the next step was to test the effects of different pH in the solution. Our first pH that was tested was pH 4. Sam added 2 mL of this to the yeast, and began timing. After she finished recording the data, our group moved onto pH 8. Subsequent to pH 8 was pH 10 (see "pH " graph and for results).
Another variable that was tested was the temperature of the water the reaction occurred in. The first temperature that was tested by the groups was 5 °C. The bucket was filled with the water, 5 mL of yeast and of hydrogen peroxide were poured into the small glass bottle.
