Bio 4A Laboratory Name:_________________Acids and Bases Lab

Procedure 1, 2 and 3. pH of common solutions, pH meter and pH calculation

Solution pH paper pH meter pH calculatevinegarhousehold ammonialemon juicecolablack coffeenonfat milkHCl 0.01M**HCl 0.001M**HCl 0.0001M**

1. **Comment on the measured and calculated values for the HCl solutions:

Procedure 4. Antacid effectiveness

Antacid Product Number of drops of acid

2. Which antacid neutralizes the greatest amount of acid? Which one neutralizes the least?

3. What can you conclude regarding the advertisements for these products?

4. How did the baking soda behave in this test? Could you use baking soda instead of an OTC antacid for your “sour stomach?”

Bio 4A LAB: Acids and Bases Worksheet (rev.5/9/2023) Page 1 of 3

Table 2. pH of some common solutions measured by paper, meter and calculated

Table 3. Effectiveness of some common antacids (one dose dissolved in 100 ml water) measured by dropwise neutralization of 0.1ml HCL

Procedure 6. Measuring the effect of a buffer on pH

No. of drops of 0.1M HCl

Pure Water Bicarbonate Sample

02468101214161820

5. Explain any difference between the pH change of the water and the bicarbonate solution when acid is added.

6. Please create a graph of these data in Excel. Use a line graph, with one line indicating pure water pH and one line indicating bicarbonate pH. Please see page Figure 1 from the lab directions

Bio 4A LAB: Acids and Bases Worksheet (rev.5/9/2023) Page 2 of 3

Table 4. pH change after acid addition to water and bicarbonate solution

Procedures 6 and 7. CO2 production and pH

7. How much time did it take for the color to change for each test subject in your group:

Before exercise?

After exercise?

8. What does this color change indicate?

9. State testable hypothesis for the question: Does the concentration of CO2 in exhaled air increase after exercise?

10.State the null hypothesis for this experiment:

11.Conceptual understanding to think about….Explain any difference in the time for color change to take place between the resting and exercise data.

12.Based upon the data collect for this experiment, what can you conclude about the mean data before and after exercise? You will need to run the appropriate statistical analysis to answer this question (hint: you are collecting data on the same subject before and after exercise).

13.Construct an appropriately label figure for your data analysis.

Bio 4A LAB: Acids and Bases Worksheet (rev.5/9/2023) Page 3 of 3