Stomach and Antacid Lab
You have learned that your stomach contains strong
Hydrochloric Acid. It is protected because of a
mucous lining. You researched ulcers and found out
that some people get a sore in their stomach because
of a few factors: a bacterial infection (H. pylori), stress,
spicy foods and extra stomach acid.
One type of medication that can help people are
antacids. Examples are: Tums, Rolaids, Malox, ENO.
In chemistry we learned that when you mix:
ACID + BASE = NEUTRAL (WATER)
Remember, this is a neutralization reaction.
This is what happens in your stomach when you take
an antacid. Antacids are bases. They neutralize extra
stomach acid.
We will test Tums Extra Strength and Rolaids
We will know when the acid is neutralized because we
will use the indicator Bromothymol Blue. It is yellow in
an acid and will turn green to blue when the mixture is
neutral and basic.
Purpose: To test which antacid works best to
neutralize acid.
Hypothesis: Which antacid (Tums or Rolaids) do you
think will work best? ___________________.
Safety: Hydrochloric acid will burn your skin and eyes:
wear goggles, gloves, lab coat ALWAYS!
Materials:
Tums or Rolaids
Mortar and Pestle
Beaker
Hydrochloric Acid with Bromothymol Blue
¼ tsp measuring spoon
Stir stick
Procedure:
1. Crush up 3 antacid tablets (either Tums or Rolaids)
using the pestle and mortar
2. Measure ¼ tsp of antacid powder and weigh it.
Record the weight. _________________grams
3. Your teacher will give you 50 mL of Acid in a
beaker.
4. Add 6 drops of Bromothymol Blue. Record the
colour of your acid. _______________________
5. Add one even ¼ tsp of antacid to the beaker. Stir
gently.
6. Continue to add ¼ tsp of antacid to the beaker.
*put a check mark in the box for every ¼ tsp you add.
7. Stop when your mixture goes a milky greenish
blue.
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Questions:
1. Which antacid did you use?
2. How many ¼ tsp scoops did it take before the
mixture went from yellow to green/blue?
3. How many scoops did the other group use?
4. Which antacid worked the best? How do you know?
5. Why do antacids work? (What type of reaction is
happening in your stomach when you take an
antacid?)