Which Antacid Raises pH the Most? - Oklahoma Biological Survey

Which Antacid Raises
pH the Most?
Biochemistry – Division II
March 6, 2007
Christopher Chan
8 th Grade
Classen School of Advanced Studies
Oklahoma City, OK

ABSTRACT
The purpose of this project was to find out which antacid neutralizes acid the most.
Antacids are commonly used for heartburn or upset stomach. The results could be beneficial for
anyone who needs an antacid to soothe their stomach.
To do this experiment, I tested seven antacids with vinegar. I chose vinegar instead of
hydrochloric acid because it is not corrosive. With a pH of 2, vinegar has an acidity that is
similar to the acidity of the stomach. The antacids tested were AlternaGEL, Gaviscon Regular
Strength Oral Liquid, Maalox Maximum Strength Multi Symptom Oral Liquid, Mylanta
Supreme Oral Suspension, Pepto-Bismol, Extra Strength Rolaids Tablets, and Extra Strength
Tums Smoothies Smooth Dissolve Tablets. I added 30 mL of each liquid antacid or three of
each type of triturated antacid tablets to 60 mL of vinegar. Then I stirred the mixture. After ten
minutes, I measured the final pH of the mixture and recorded the data.
I discovered that Mylanta Supreme Oral Suspension neutralized the acid the most. Next
was Extra Strength Rolaids Tablets followed by Extra Strength Tums Smoothies Smooth
Dissolve Tablets, Gaviscon Regular Strength Oral Liquid, Maalox Maximum Strength Multi
Symptom Oral Liquid, and AlternaGEL. Pepto-Bismol neutralized acid the least. The antacids
containing a combination of calcium carbonate and magnesium hydroxide neutralized the acid of
the vinegar the most. Therefore, the use of Mylanta Supreme Oral Suspension or Extra Strength
Rolaids Tablets should be the top choices when choosing effective antacids.

INTRODUCTION
My experiment is “Which Antacid Raises pH the Most?” The purpose of this experiment
was to determine which antacid is the most effective in neutralizing stomach acid. My
hypothesis was that if all antacids are not the same, then I can discover the most effective
antacid; therefore, I will know which antacid neutralizes acid the most. Antacids are different
because the ingredients in them are different. I tested different combinations and forms of
antacids. I used oral suspensions and chewable tablets. I tried to find out which antacid is the
best. The results of this experiment could be beneficial for anyone who needs an antacid to
soothe their upset stomach.
An antacid is a type of medicine that neutralizes stomach acid. It is used when your
stomach feels upset. The pH level in your stomach is from 1.5 to 2.5. (1) I used vinegar that has
five percent acidity for this experiment because vinegar has a pH of 2 and is less corrosive than
hydrochloric acid. The stomach produces hydrochloric acid which aids in the chemical digestion
of food. The stomach is protected from the acid by a mucous lining. This mucous lining
prevents the stomach wall from being eaten up. (2)
Antacids neutralize stomach acid. They can be used when you have heartburn, an upset
stomach, or acid indigestion. (3) Most antacids contain magnesium hydroxide, aluminum
hydroxide, calcium carbonate, or a combination of these. (4) Antacids that contain magnesium
can cause diarrhea. Patients in renal failure need to use extreme caution when taking antacids
that contain magnesium. Aluminum or calcium containing antacids could lead to constipation.
Although antacids bring the quickest relief, they last for a short amount of time. (5)
The measure of the hydrogen ion concentration is pH. In the late 1880s, Svante
Arrhenius, a Swedish chemist and physicist, said that an acid was made of hydrogen ions. (6)

This led to the modern definition of pH today. The pH scale ranges from zero to fourteen with
zero being the most acidic and fourteen being the most basic. Seven is neutral. The pH scale
uses a logarithmic scale. Therefore, it covers a large range of acidity values. (7)
A neutralization reaction occurs when an acid combines with a base. An acid tastes sour
when dissolved in water, turns blue litmus paper red, and neutralizes bases. Bases taste bitter
and feel slippery when dissolved in water, turn red litmus paper blue, and neutralize acids.
When a neutralization reaction occurs, the properties of the mixture are not similar to the
properties of the acid or the base. A neutralization reaction produces water and a salt.
MATERIALS
4,200 mL of vinegar
pH meter
300 mL of AlternaGEL
300 mL of Gaviscon Regular Strength Oral Liquid
300 mL of Maalox Maximum Strength Multi Symptom Oral Liquid
300 mL of Mylanta Supreme Oral Suspension
300 mL of Pepto-Bismol
30 Tablets of Extra Strength Rolaids
30 Tablets of Extra Strength Tums Smoothies Smooth Dissolve Tablets
100 mL graduated cylinder
7- 400 mL beakers

7 glass stirring rods
Glass mortar and pestle
METHOD
1.) Labeled each beaker from 1 to 7.
2.) Put 60 mL of vinegar in each of the seven beakers.
3.) Measured the pH of the vinegar using the pH meter.
4.) Recorded the pH of the vinegar.
5.) Added 30 mL of AlternaGEL to beaker #1.
6.) Stirred the vinegar and antacid mixture for 10 minutes.
7.) Measured the final pH of the vinegar and antacid mixture with the pH meter.
8.) Recorded the data.
9.) Cleaned the pH meter.
10.) Added 30 mL of Gaviscon Regular Strength Oral Liquid to beaker #2.
11.) Repeated steps 6 through 9.
12.) Added 30 mL of Maalox Maximum Strength Multi Symptom Oral Liquid to beaker
#3.
13.) Repeated steps 6 through 9.
14.) Added 30 mL of Mylanta Supreme Oral Suspension to beaker #4.
15.) Repeated steps 6 through 9.
16.) Added 30 mL of Pepto-Bismol to beaker #5.
17.) Repeated steps 6 through 9.

18.) Triturated 3 tablets of Extra Strength Rolaids using the mortar and pestle.
19.) Poured the Extra Strength Rolaids powder into beaker #6.
20.) Repeated steps 6 through 9.
21.) Triturated 3 tablets of Extra Strength Tums Smoothies Smooth Dissolve Tablets
using the mortar and pestle.
22.) Poured the powder from the Extra Strength Tums Smoothies Smooth Dissolve
Tablets into beaker #7.
23.) Repeated steps 6 through 9.
24.) Washed and dried all 7 beakers.
25.) Repeated steps 1 through 24 nine more times.
26.) Plotted line graph with the x-axis as the antacids and the y-axis as the final pH of the
mixture of the vinegar and the antacid.
27.) Plotted line graph with the x-axis as the antacids and the y-axis as the average pH
from trial #1 through trial #10 for each antacid.
28.) Plotted line graph with the x-axis as the antacids and the y-axis as the difference in
pH from the vinegar and the average pH of each antacid.
29.) Analyzed and evaluated results.
RESULTS
I discovered that Mylanta Supreme Oral Suspension neutralized the acid the most. The
average final pH of Mylanta Supreme Oral Suspension and vinegar after ten minutes was 6.59.

The next most neutralizing antacid was Extra Strength Rolaids Tablets followed by Extra
Strength Tums Smoothies Smooth Dissolve Tablets, Gaviscon Regular Strength Oral Liquid,
Maalox Maximum Strength Multi Symptom Oral Liquid, and AlternaGEL. Pepto-Bismol
neutralized acid the least. Pepto-Bismol and vinegar had an average pH of 2.59 after ten
minutes. The average variation in pH of the antacid and vinegar mixture was 0.07 for
AlternaGEL, 0.13 for Gaviscon Regular Strength Oral Liquid, 0.08 for Maalox Maximum
Strength Multi Symptom Oral Liquid, 0.09 for Mylanta Supreme Oral Suspension, 0.08 for
Pepto-Bismol, 0.16 for Extra Strength Rolaids Tablets, and 0.11 for Extra Strength Tums
Smoothies Smooth Dissolve Tablets.

DISCUSSION OF RESULTS
The data shows that Mylanta Supreme Oral Suspension neutralized the vinegar the most.
The antacids containing calcium carbonate and magnesium hydroxide were Mylanta Supreme
Oral Suspension and Extra Strength Rolaids Tablets. These antacids neutralized the vinegar the
most. The average final pH of the mixture of Mylanta Supreme Oral Suspension and vinegar
after ten minutes was 6.59. The average final pH of the mixture of Extra Strength Rolaids
Tablets and vinegar after ten minutes was 5.09. Calcium carbonate and magnesium hydroxide
combined to produce the highest pH results in my experiment. The antacids that contained other
active ingredients alone or in different combinations such as aluminum hydroxide, bismuth
subsalicylate, calcium carbonate, magnesium carbonate, and magnesium hydroxide did not
neutralize the pH of the vinegar as much.
CONCLUSION
Based on the results of this experiment, Mylanta Supreme Oral Suspension is the antacid
of choice for the relief of upset stomach, heartburn, and acid indigestion. Mylanta Supreme Oral
Suspension should not be used in renal failure because it contains magnesium hydroxide.
Elevated magnesium levels can lead to cardiovascular and neurological problems. Mylanta
Supreme Oral Suspension may cause hypercalcemia and is contraindicated in patients that have
had kidney stones in the past.

ACKNOWLEDGEMENT
I would like to give special thanks to Ms. Linda Barnett, my science teacher, for
supervising and guiding me throughout the Science Fair process. I would also like to thank my
parents, Peter and Betty Chan. They supported and encouraged me all the way. They also
provided the materials necessary for my project.
REFERENCES
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from World Book Online Reference Center database: http://www.worldbookonline.com/
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to heal heartburn and acid reflux (p. 61). New York: John Wiley and Sons.
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everywoman needs-real solutions to stop the pain and achieve lasting digestive health
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5. Miskovitz, P., M.D., & Betancourt, M. (2005). Treating reflux disease. In The doctor’s guide
to gastrointestinal health: Preventing and treating acid reflux, ulcers, irritable bowel
syndrome, diverticulitis, celiac disease, colon cancer, pancreatitis, cirrhosis, hernias,
and more (p. 55). Hoboken, NJ: John Wiley and Sons.
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connections (2nd ed., p. 72). San Diego, CA: Academic Press.
7. Hess, F. C. (1984). PH. In Chemistry made simple (Rev. ed., p. 76). New York: Doubleday.
(Original work published 1955)