How Do Antacids Work?

Source Institutions

Source Institutions

Add to list Go to activity
You just ate a big meal and feel heartburn coming on. You take an antacid and feel better. Why? Heartburn is caused by stomach juice (an acid) burning the esophagus. In this activity, dye, fake stomach juice and antacid are used to show how antacid (anti-acid) soaks up the loose hydrogen atoms (acid) in the fake stomach juice. [Activity is publicly available through a web crawler capture on]

Quick Guide

Preparation Time:
10 to 30 minutes

Learning Time:
30 to 45 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 11 - 18

Resource Types:
Activity, Experiment/Lab Activity


Materials List (per group of students)

  • Bottle of antacid (the tablets should be broken into smaller pieces)
  • A Mortar and pestle
  • Dropper bottle with fake stomach juice = (0.01M HCl, or use vinegar)
  • Round wooden sticks in plastic container
  • Dropper bottle with dye (pH indicator diluted to 20% in water) Any indicator dye that can differentiate between pH 2 and 7 will work.
  • Plastic cups


  • Life Sciences
    • Human Body
      • Digestion
  • Physical Sciences
    • Chemistry
      • Chemical Reactions
      • Acids and Bases


To use this activity, learners need to:

  • see
  • see color
  • touch

Learning styles supported:

  • Uses STEM to solve real-world problems
  • Involves hands-on or lab activities


Access Rights:

  • Free access


Source Collection

  • Pfizer Foundation Biochemistry Discovery Lab


  • All rights reserved, New York Hall of Science, 2001

Funding Sources:

  • Pfizer Foundation
  • National Science Foundation, 9814954
  • The Camille and Henry Dreyfus Foundation, Inc.