Learning Activity: pH Level of Pop

Explanation of the activity:

Bone calcium is turned into alkaline by the body to neutralize pH in pop, thus depleting bone calcium. This experiment is designed to test the pH level in various beverages to identify the beverage with the lowest pH level. The lower the pH, the more likely the beverage will aid in bone calcium depletion.

Note: It may be more cost-effective to purchase 2-liters instead of 6-packs of pop. Also, even though the students are conducting the experiment individually, have students share a pH meter in groups of 6 unless you have opted to use the pH strips.

Preparation:

Lay out all the materials for the students. Mark the inside of the plastic cups at the same level so the students pour the same amounts of pop in the cup for testing. Make sure not to open the pop before the experiment. The results may change depending on the flatness of the pop.

Directions:

1. Assign students to test Coca-Cola, Pepsi, Mountain Dew, Sprite, Orange Soda, Root Beer, water, or milk. Note: Please make sure that the class is evenly dispersed with the different types of beverages. Ask students to predict the pH levels of their respective beverage. Write some of the predictions on the chalkboard. Have the students fill in the “Hypothesis” and pH level guesses on their Lab Sheets.

2. Have each student gather their 3 cups and pour their respective beverage into the first cup up to the designated mark. To test the pH level, place the pH meter or pH strips in the beverage and wait 10 seconds or until the numbers or color stops changing. Have students record the number that is on the pH meter or the number that is associated with the color on the pH strips. The student should repeat this process two more times and take the average of the results. Note: Since the students will be sharing a pH meter within the group, have each student wait to open their pop until it is their turn to test the pop using the pH meter.

3. Have students complete the experiment using the directions outlined on the Lab Sheet and answer the follow-up questions.

4. At the conclusion of the experiment, have each student present their findings and discuss their conclusions.