A STUDY OF ALKA-SELTZER IN DIFFERENT TYPES OF
LIQUIDS
Peyton Gozon
Cary Academy
2013
ABSTRACT
The purpose of this study was to determine if Alka-Seltzer would
dissolve quicker depending on the amount of pieces in the liquid.
Alka-Seltzers are made to dissolve quickly, in a whole tablet in
water to relieve headaches, Stomach pain and heart burn. AlkaSeltzer was taken and broken apart into 2, 4, and 8 even pieces,
Also there was a whole tablet being tested. The 4 pieces of AlkaSeltzer had the best time dissolving time, this is because the 4
Figure 1: Basic idea of the nucleation
process. The small circles are the co2
pieces is the right size for the quickest nucleation process (The
bubbles rising off
nucleation process is where CO2 forms in small divots on the AlkaSeltzer, and the CO2 is released), and the 2 pieces took slightly longer to dissolve, and the
whole tablet took the longest, however 8 pieces took longer than the 4 pieces because the tablet
is too small for the nucleation process. This is because the Nucleation process forms co2 around
the tablet, dissolving the tablet, in this case reducing the pH of the liquid. However if the site
for the Nucleation process is smaller, then it slows down, but if there are pieces then that is
almost 2x as fast as the whole tablet.
INTRODUCTION
In the year 1931, the Alka-Seltzer tablet was made. This tablet relieved heartburn, upset
stomachs, acid indigestion with headaches and body aches. Alka-Seltzer tablets contain mainly
1916mg of sodium bicarbonate, 325mg of Aspirin, and 1000mg of anhydrous citric acid. There
are some experiments that have been done before, even at this school. Enoch Kuan did an
experiment that tested how long it took an Alka-Seltzer to dissolve in different types of liquids
and amounts of the liquid. In water the Alka-Seltzer dissolved the quickest and it dissolved
slower in sprite. It was also found that the more liquid the Alka-Seltzer tablet was put in, the
quicker it dissolved. There are some experiments that have been done before. Enoch Kuan did
an experiment that tested how long it took an Alka-Seltzer to dissolve in different types of
liquids and the different amounts of the liquid. In water the Alka-Seltzer dissolved the fastest
and it dissolved slower in sprite. It was also found that the more liquid the Alka-Seltzer tablet
was put in, the quicker it dissolved.
Alka-Seltzer is put in water, drank and then the stomach, after some time, is feeling better.
Alka-Seltzer works fast because it is already in a solution when
it
is taken, so it is absorbed quickly. That means there is rapid
relief from the stomach, heartburn, acid indigestion or
headache. Alka seltzer contains Acetylsalicylic acid or aspirin,
Citric acid and Sodium bicarbonate. Alka-Seltzer reactions, and
they create sodium citrate (anti acid) and sodium
acetylsalicylate (paint reliever).
Sodium citrate is a proven substance for neutralizes acids. It
acts as a buffer, to the gastric acid lowers the concentration of
the acid. Things that do this called anti-acids.
Acetylsalicylic acid is aspirin; however the advantage to AlkaSeltzer is that the acetylsalicylic acid is because Alka-Seltzer is
absorbed in water. This allows the acid to get down quicker and
go to the small intestine where it starts to relieve pain.
Carbon dioxide is an odorless, colorless gas and is one of the
gasses that make up part of the atmosphere (Carbon dioxide is
about 394.39 ppm (parts per million)). Around the year 1630 a
Flemish scientist Jan van Helmont found out that some
different vapors differed from air. He created the term gas to
describe these vapors. In 1756 Joseph Black probed that carbon
dioxide (or called fixed air) is in the atmosphere and that it forms
compounds when mixed with some other chemicals. The amount
of carbon dioxide has been significantly increased since the mid
1800’s because of the factories producing it. Carbon dioxide is
heavier than air. Carbon dioxide is known as co2,
because it contains 1 carbon atom and 2 oxygen
atoms. A ball and stick diagram of carbon
dioxide:
Figure 3: Carbon
Carbon dioxide is used in many things that are used every day. One of the
Dioxide "ball and stick"
main things is it creates “sparkling water” or water that fizzes. The sparkling model.
water is normally drunk as a carbonated soft drink. It is also used to create the candy Pop Rocks
and Baker’s Yeast. Carbon dioxide is also used in the process of wine making. It gets turned
into “dry ice” or a solid very cold form of carbon dioxide. The dry ice is used to cool down
large amounts of grapes quickly to slowdown and to prevent spontaneous fermentation by wild
yeast, spoiling the grapes and reducing the sugar in the grape must, which lowers the alcohol
content. Carbon dioxide has a lot of practical uses like the fire extinguisher because fires need
to have oxygen in order to “live” or to keep burning. The carbon dioxide replaces the oxygen
Figure 2: Main symptoms of carbon dioxide at
different carbon dioxide levels.
and then the fire starts to die out. Liquid carbon dioxide is used to keep some refrigerators cool.
However carbon dioxide can also harm someone. If the concentrations get to 1% (10,000 ppm)
it can make a person drowsy. It the concentrations get to 7 – 10% it could cause suffocation,
headaches, visual and hearing problems and making the person go unconsciousness for a few
minutes to an hour. Carbon dioxide is still a very useful thing to have around.
Stomach acid also known as Gastric acid, has a pH of 1.5 – 3.5. It contains about 5000 ppm of
hydrochloric acid, large quantities of potassium chloride and sodium chloride. The cells that
line the walls of the stomach produce the acid to help digest the different foods in the body. The
presence of Gastric acid was first found by a USA army surgeon, William Beaumont around
1830.
Stomach acid is created by the lining stomach cells, when they split chloride and hydrogen ions.
The cells that do this are called parietal cells, they have proteins that pumps out hydrogen ions
out of the cell and potassium ions into the cell. Both ions are positively charged, and the
proteins prevent an imbalance of positively and negative charge. The ions that where pumped
out are pushed into the stomach, where they pass over a pH neutral area (the mucus that lines
the walls) and into the stomach. While this happens some other cells in the stomach produce
bicarbonate, a base that is used to buffer the liquid to it does not become too acidic. People
normally will take something like an Alka-Seltzer when the acid is too acidic because AlkaSeltzer has some bicarbonate in it.
MATERIALS AND METHODS
The items used in the experiments were 500 mL beakers, orange juice, white distilled vinegar,
lemon juice, Alka-Seltzer, pH strips, and water (room temperature, hot and, cold.
Alka-Seltzer was placed into 100mL of orange juice, lemon juice, and white distilled vinegar.
The starting pH of the three liquids was taken before the Alka-Seltzer. After the Alka-Seltzer
dissolved, the final pH was also taken and written down. This was repeated 3 times and an
average was taken.
Alka-Seltzer was taken and broken into 2, 4, and 8 pieces, there was also a whole tablet, and
placed in 100mL of water to find the dissolve time. The tablets were put together in one as one
beaker would have the 8 pieces, while another one would have the 4 pieces. While they
dissolved the time was recorded. This was repeated 3 times and an average was taken.
Alka-Seltzer was taken and broken into 4 pieces, powder and one was left whole, and placed
into 50mL of White Distilled Vinegar. The pH of the White Distilled Vinegar was taken every 5
sec and recorded up to 125 sec because this was the time of the first whole tablet and the one
that took the longest time to dissolve. This was repeated 3 times and an average was taken.
Alka-Seltzer was put into 100mL of 77, 21 and 15°c water. The time was taken to see how long
it took to dissolve in the water. The time was taken while the Alka-Seltzer was dissolving. This
was repeated 3 times and an average was taken.
pH of liquid
RESULTS AND DISCUSSION
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Before PH
After PH
Lemon Juice
Orange Juice
White Distilled
Vinegar
Type of liquid
Figure 4: The pH of before and after an Alka-Seltzer was put into each liquid
It was found that Lemon Juice had the most dramatic change in pH. This is because Lemon
Juice starts with a very acidy pH of 2, there for the Alka-Seltzer does what it was made to do,
neutralize the acid. Also the stomachs pH is from 1.5 to 3.5, so Alka-Seltzer is made to tackle
low pH liquids. However the Orange Juice’s pH only changed by 1 pH. This is because AlkaSeltzer is made to neutralize the pH of something, and 7 is the base pH. The White Distilled
Vinegar only changed by 2 pH, and ended with 6 as its final pH because Alka-Seltzer was made
to change the pH of liquids like Gastric Acid (Stomach acid), and dissolve in things like water.
60
Time to dissolve (sec)
50
40
30
20
10
0
0
2
4
6
8
10
Amount of tablet parts
Figure 5: The time taken to dissolve in 100mL of water.
It was found that it was most effective to break apart the tablet into 4 pieces when trying to
dissolve the tablet quicker. This is because Alka-Seltzer relies on a thing called the Nucleation
process. The Nucleation process is where tiny pockets of air form on the Alka-Seltzer, and they
release carbonating the water (most of the time) and dissolves the chemicals in Alka-Seltzer.
There are 12 different locations for the Nucleation process to happen, all the tops, bottoms and
sides, releasing much more gas. Also using a whole tablet took the longest, because that means
there are only 3 areas for the tablet to do the Nucleation process, the top, bottom and side, there
for slowing it down. However when the tablet is broken into 8 pieces, it is slowed down also,
because there is too much gas being released at once so not as much water can get back onto
the tablet.
8
pH of the vinegar
7
6
5
4
Tablet
3
4 pieces
2
Powder
1
0
0
20
40
60
80
100
120
140
Time (sec)
Figure 6: The pH of 50mL of vinegar over 125 sec when there is a whole tablet, 4 pieces or a powder.
It was found that the Tablet and the 4 pieces both turned the White Distilled Vinegar’s pH into
7, however the Powder did not. This is because the Tablet and 4 pieces have more surface area
for the Nucleation process; however there are more sides for the Nucleation process on the 4
pieces. Also the 4 pieces have proven to be more effective in the earlier above. However the
Powder was not very effective, as the small places are too small for much Nucleation;
effectively slowing it down. Also some of the powder will not dissolve, but instead sit on top of
the Vinegar, as they are the pieces too small for the Nucleation process, also lowering how
effective it is.
Temperature of water (c)
80
70
60
50
40
30
20
10
0
0
20
40
60
80
100
Time taken to dissolve (sec)
Figure 7: How long the Alka-Seltzer took to dissolve in different temperatures (c) of water.
It was found that Alka-Seltzer dissolves a lot quicker in hot water, as the molecules are moving
around franticly in hot water, so that speeds up the Nucleation process and pull the Alka-Seltzer
apart. The molecules move quicker because hot water is normal water, but with heat energy
added in. The heat adds increases the kinetic energy for the molecules, making them move
quicker. However in cold water, the molecules have the cold energy added onto them, reducing
the kinetic energy kinetic energy for the molecules therefore slowing them down. In normal
temperature (room temperature) the molecules are balanced out and it dissolves them at a
normal rate of about 20 sec.
CONCLUSION
It was found that Alka-Seltzer dissolves the quickest in hot water, over the other materials
tested, this is due to the fact that Alka-Seltzer is manufactured to dissolve in water and to
dissolve quickly. This data could be helpful for those who have an upset stomach, heartburn, or
headache, Alka-Seltzer dissolves the fastest in hot water, this is useful for those who want to be
able to drink the Alka-Seltzer quick, however room temperature water is also about as good, for
those who can wait and don’t want to burn themselves. The results were not surprising as the
Alka-Seltzer was made to be put into water, and heat adds on a second energy source for the
molecules, speeding the molecules up. In the future it would be interesting to determine if the
Alka-Seltzer dissolves quicker or slower when put into a compound liquid like hydroxide, or if
the Alka-Seltzer was put into a liquid combination to see if the compound changes the speed of
which an Alka-Seltzer dissolves.
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