1. Analyzing Antacids
Science 10

2. Background Information
Chemical reactions change the food you eat into compounds that your body uses to grow, maintain & repair cells & tissues & provide energy.
These reactions are collectively known as digestion.
The stomach is one of several organs involves in digestion.

3. Stomach

4. The stomach secretes an acid that helps break down food particles.
This acid can cause a condition called heart burn / acid indigestion.
It occurs when the stomach contents are pushed into the lower area of the esophagus
The esophagus does not have a protective lining like the stomach, so you feel a burning sensation in your throat & chest

6. Creating an Experiment
In this investigation, you and your partner will study one aspect of antacids
Formulate a question based on information you have studies in this unit
Then decide how you will carry out an experiment to answer your question

7. Think about it !
Go to page 132 – 133 in your science 10 text book to look at some suggested areas and methods of this investigation

8. By the End of Class I Must See:
Introduction
Hypothesis/Prediction
Step by step procedure with diagram
Data / observation section (creation of a table?)

9. Materials available to you:
150 mL beakers
Bromothymol blue
HCl (5-10 mL limit of HCl per antacid)
Sodium bicarbonate (used to neutralize HCl)
pH paper
pH meter
Weigh boats
Antacids (Rolaids, Tums, Pepto bismol, Maalox, Alka-selter)

10. About materials: Do NOT exceed 10 mL of HCl per antacid tablet
Rule of thumb: 100mg of antacid = 1mL of HCl
Take only 1 antacid tablet per use
Use beakers to mix acid/base with antacid
Use granulated cylinders for measuring ONLY
Use HCl to neutralize the antacid (to reduce amount of HCl used)

11. Possible investigation questions:
Does a neutralization reaction take place? If so, how can you use indicators to compare effectiveness of active ingredients in antacids?
How do antacid tablets of different brands compare in terms of neutralizing ability? What does this have to do with mass of the tablet or active ingredient?
What are the products of the reaction between an antacid and an acid?

12. Things to think about: Will you need to weigh your antacid?
Will you need the same amount of HCl or sodium bicarbonate?
How will you measure the pH?