Kevin Osei
Culminating Lab: Determining the Most Effective Antacid
Background:
Heartburn (A.K.A. acid indigestion) is the burning feeling in someone’s chest/stomach after
consuming certain foods or beverages. Every week, around 5 million Canadians experience this pain
every week! Heartburn is caused by having the gastric juices from your stomach regurgitate up through
your esophagus, and it is not a very good sensation to have.
These gastric juices in your stomach have hydrochloric acid (HCl), and usually, this chemical has
a pH of around 2. This is actually corrosive enough to burn and damage many things it touches. And if
this raises up into your esophagus, you won’t be feeling the best. A way to battle heartburn can be
neutralizing the acid, with antacids. These are mild bases that can neutralize the acids, in liquids,
chewables, tablets, and other forms. But which of these various antacids will be most effective? And
which will be worth the money?
We will be testing 3 different types of liquid antacid. Philips Milik of Magnesia, Life Brand Milk of
Magnesia, and Diovol Plus AF. The prices for the respective brands are $8.99, $7.99, and $9.99. We will
find out which brand is the most effective at neutralizing the acid.
Hypothesis:
Looking at the background information given, I am going to blindly assume that the Diovol Plus
AF will be the most effective antacid. I am assuming this because usually, with medical things like these,
and in situations like these, the most expensive would be the superior one, because you would paying
the extra few dollars for quality.
Materials:
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Safety goggles
2 100 mL beakers
Stirring rod, eye droppers (Pippettes)
Antacids, 0.2 M Hydrochloric acid (HCl)
Phenolphthalein, Universal pH paper
Method:
1. Obtain an antacid brand beaker from the front counter. Write down the name of the brand in
the chart.
2. Transfer your 5 drops of antacid liquid into a small beaker.
3. Using pH paper, take an initial measurement of the pH of your antacid solution. Record these
values in your observation chart.
4. Add one drop of phenolphthalein and stir the mixture using stirring rod. Observe.
5. Using medicine dropper, add drops of HCl to your antacid mixture. Count diligently. Stir per 10
drops
6. Record all results.
7. Stop test when antacid becomes fully neutralized.
8. Repeat steps 1-7 with remaining antacid brands.
Observations:
Antacid Brand
Diovol
Phillips
Life Brand
Number of Drops
of Antacid
5
5
5
Initial pH Paper
Colour & pH
Reading
Bright yellow, 7
Bright yellow, 7
Bright yellow, 6.5
Number of Drops
of HCl Acid added
to Change
Indicator Colour
to Clear
7
160
220
Final pH Paper
Colour &pH
Reading
6.5
6.5
5.5
Results:
With each antacid brand, my group had only used 5 drops. All three had an initial pH paper
rating of around 7, and had a pH colour of a bright yellow. For the Diovol antacid, we had to use 7 drops
of HCl acid to it to make it neutral. This would indicate that the diovol can only handle 7 drops of the
HCl. The final pH paper reading for this was 6.5. The Phillips Milk of Magnesia antacid required 162
drops of acid to have it neutralized. This means that the Phillips brand can handle 162 drops of HCl acid.
The final pH paper reading was 6.5. The Life Brand Milk of Magnesia needed 220 drops of HCl acid to
change the base to a neutral substance. If this is correct, this would mean that this antacid can take on
220 drops of HCl. This final pH paper reading was 5.5.
Conclusion:
From our results and observations, I had realized that what I had hypothesized was completely
wrong. Because of previous experiences, I had assumed that the Diovol would be much stronger of an
antacid, because of the fact that it costs the most. Usually with this type of situation, the more you pay,
the better you get. It was a bit naive and blunt of me to assume this instead of thoroughly checking the
ingredients. But by looking at this, I have noticed that the Life Brand Milk of Magnesium is by far the
strongest. It can take on 220 drops of HCl acid, much more than the Phillips, which can only take 162,
and the Diovol, which can only take 7. To purchase the Life Brand would be definitely more efficient, not
only because it is the strongest, but also because it is the strongest.
Discussion:
1. Based on my results, the most effective antacid was definitely the Life Brand Milk of
Magnesium. I had not taken down the most active ingredient in any of the three antacids, so I
could not be able to state the most active ingredient in this particular antacid.
2. One source of human error that we may have encountered could have been not being careful
with the droppers. We could have put in too much, or too little of the antacid, the indicator, or
the HCl acid into the mixture. An experimental error that could have occurred could have been
not washing the beakers clean enough. This could throw off the whole experiment. Considering
how concentrated the antacids are, if we were careless enough to leave a single drop in, we
could have had to add another hundred drops of HCl into our mixture.
3. In my opinion, adding the ACID to the BASE wasn’t very realistic, but it was much more precise.
Realistically, we use the base (the antacid) to neutralize the acids in our stomachs. But what’s
interesting about the antacids are that they are much stronger and concentrated than thought.
If it took 220 drops of HCl to neutralize only 5 drops of antacid, it would be very hard to figure
out how many drops of antacid it would take to neutralize the HCl. Unless you are incredibly
lucky, chances are the antacids would not neutralize the HCl, but overthrow the acids, and turn
it into a weak basic substance.
4. Scientifically speaking, it is somewhat more beneficial to take the antacid after you feel the
heartburn. That’s if we are talking about taking it after consuming the foods that trigger
heartburn. If you take the antacids before you eat, you will be left with unnecessary amounts of
a basic substance with no reason for it to be there. It would be best to take the antacids only
after you are done eating.
5. In regards to antacid effectiveness, an additional question I would be interested in researching
would be “How effective are the tablets compared to the liquid antacids?”
My experimental procedure for this situation would have to do with grinding up the tablets into
powder and adding the suggested amount of water to be taken with it, taking the pH value,
adding the indicator, and adding HCl into the mixture to see how much acid it could handle.