The Most Potent Antacid

Science Fair Project made by: Nabiha Choudhury


Which antacid is most potent?


I think Pepto-Bismol will be most potent because it is the only one with color and I think it is the strongest antacid out of all antacid because it has many uses.


  • Grape Juice (no sugar)
  • Eye Dropper
  • Lemon Juice
  • Several Test Tubes (I used glasses)
  • Several different types of Liquid Antacids: Pepto-Bismol, Up&Up Liquid Antacid, Equate maximum strength Liquid Antacids, Gaviscon Extra Strength Liquid Antacid, Rolaids Liquid Antacid


Independent variable-all of the antacids

Dependent variable-the change in color

Control variable- the amount of lemon and grape juice needed.


  1. Add ten drops of grape juice to each test tube.Grape juice is a natural acid-base indicator ,so it turns colors depending on whether the solution it is placed in is a acidic or basic.
  2. Rinse the eyedropper thoroughly
  3. Add ten drops of lemon juice (an acid)to each test tube.
  4. Name each test tube with the name of one of the liquid antacids you are testing.
  5. Add the first antacid drop byr drop to the first test tube, stop as soon as it changes color.A color change means the antacid neutralized the acid in the lemon juice.
  6. Record the number of drops it took to make the color changes
  7. Repeat the process with the remaining types of antacid adding drops of one antacid to each remaining test tube.
  8. Record results.


PeptoBismol- 1st trial:17 drops,Turned light magenta,2nd trial:12 drops,Turned light pink

3rd trial:10 drops,Turned light magenta

Gaviscon- 1st trial:6 drops,Turned pink,2nd trial :7 drops,Turned pink,3rd trial:7 drops,Turned light pink

Rolaids-1st trial:5 drops,Turned black,2nd trial:4 drops,Turned black,3rd trial:6 drops,Turned brown

Up&Up-1st trial:16 drops,Turned hot pink,2nd trial:19 drops,Turned pink,3rd trial:15 drops,Turned dark hot pink

Equate-1st trial:27 drops,Turned light pink,2nd trial:22 drops,Turned light pink,3rd trial:20 drops,Turned bubble gum pink


My hypothesis was incorrect because PeptoBismol was not the most potent antacid or change color in the the least amount of drops,it was Rolaids. Pepto took more drops and Rolaids to the least amount of drops.


  • Antacid works by neutralizing a acid in a chemical reaction
  • It is used to relieve upset stomach,sour stomach, and heartburns
  • Antacids have a rapid onset and short duration of action.Rapid relief
  • Antacid might be in to classes.One that works with chemicals neutralization of gastric acid and one that uses adsorption of acid.(non-absorbable antacid)
  • Chemical antacid show most rapid action,may cause a condition where the gastric acid relieves greater concentrations after drug effect stay
  • Calcium and magnesium salts is adsorption of the acid,are less prone with the rebound effect
  • An acid is a chemical substance whose solution characterized by a sour taste, and can turn blue litmus red