Name _____________________________________
Subject __________________, Period ____ Teacher __________________
Texas High School
Date ____________
Lab Worksheet – My Tummy Hurts
Table 1
Acid solution
Base solution
Color of Phenophthalein
Table 2 – How much stomach acid will my antacid neutralize?
Measurement taken
Antacid 1
Antacid 2
Brand of Antacid Tested
Antacid 3
Weight of the Powdered Antacid Table (grams)
Initial Na(OH) Reading (milliliters)
Final Na(OH) Reading (milliliters)
Total Na(OH) Volume Used To Neutralize
Remaining Stomach Acid (milliliters)
Milliliters of Stomach Acid Neutralized by the
Entire Antacid Tablet
Milliliters of Stomach Acid Neutralized by
ONE GRAM of Antacid
Milliliters of Stomach Acid Neutralized by
ONE PENNY’s Worth of Antacid
1. Which antacid that you tested neutralized the greatest amount of acid per table? ______________
2. You have 75 ml of HCl in your stomach. How many tablets of your best antacid would you have
to take before the entire 75 ml of acid was neutralized? ______________
3. Which antacid that you tested neutralized the greatest amount of acid per gram? ______________
4. Which antacid that you tested neutralized the greatest amount of acid per penny? _____________
5. Based on the class data, and taking all calculations into consideration, which ONE antacid would
you recommend that your family and friends purchase? _________________
6. Based on the class data, and taking all calculations into consideration, which AONE antacid
would you least recommend for your family and friends to purchase? ____________________
7. You are experiencing an upset stomach and take an antacid that contains Mg(OH)2 to neutralize
your excess stomach acid. A neutralization reaction occurs and your stomach feels much better!
What chemical compounds are now present in your stomach? Please write the correct chemical
formulas for the compounds now found in your stomach.
Mg(OH)2 + HCl  __________________ + __________________
8. You get ready to test the strength of a new antacid using the titration method. Just before titrating
you realize you are out of Phenolphthalein Indicator Solution. OH NO!!! You find some Phenol
Red Indicator Solution in the cabinet and decide to use it instead. You add the Phenol Red to your
“stomach” flask and begin titrating. How will you know when all the acid has been neutralized?
9. List TWO reasons why a buret is a great laboratory tool to use when completing a titration.
10. Write a pH number that would best fit the following situations as they occurred during this
training lab.
A. The “stomach” acid before adding anything to it. ______________
B. The “stomach” acid after adding an antacid tablet. ______________
C. The Na(OH) you placed in the buret. ____________
D. The “stomach” acid after adding an antacid tablet, phenolphthalein, and titrating with
Na(OH) until the solution turned a pink color. ________________
E. The antacid tablet if you were to dissolve it in distilled water. _____________