The Reaction of Coke and Mentos
Group # 8
Joe Tunnera
Nick Vassiliadis
Kevin Uyleman
Marlborough High School
STEM ECHS
January 10, 2014
The Reaction of Soda and Mentos
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Problem Statement:
Which brand of soda, Coke, Diet Coke, Sunkist, or Barq’s, will shoot the highest when mixed
with Mentos?
Research
Nucleation
Nucleation is the extremely localized budding of a distinct thermodynamic phase. (Nucleation,
2013.) Nucleation is important in Group 8’s project because when soda is combined with
Mentos, it creates a geyser. This happens because gas bubbles form off of the Mentos and rise
to the top of the soda bottle/can/etc. Then the bubbles escape from the top at a high pressure,
forming a geyser. Nucleation is more of a physical change that chemical change. Nucleation is
important to Group 8’s project because without nucleation, there would be no geyser.
Nucleation, in this experiment, can only happen with Mentos.
Mentos
Mentos are a key part of Group 8’s experiment. Mentos combines with soda and reacts through
nucleation. The ingredients in a single Mento are sugar, glucose syrup, hydrogenated coconut
oil, gelatin, dextrin, natural flavor, corn starch, and gum. The rough dimply surfaces of Mentos
encourage bubble growth because they efficiently disrupt the polar attractions between water
molecules, creating bubble growth sites. It has been determined that mint Mentos has the
The Reaction of Soda and Mentos
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biggest reaction of all of the Mentos flavors. Also, colored candies have a smaller geyser than
candies that do not have coloring. Mentos would have no reaction without the independent
variable, the soda.
Control and Variables
For the control of the experiment, Group 8 decided to use Coca Cola. Coca Cola would be the
best choice for this experiment because it is one of the most common types of soda that a lot of
people drink. For the independent variables for the project, it was decided to use only products
sold by The Coca Cola Company. This way, the results of the experiment would have fewer
problems because different soda companies use different ingredients to make the soda. So if the
experiment only has one brand of soda, the results would be more balanced and the chemicals
that caused the reaction would be found easier. In this experiment, Group 8 decided to use diet
Coca Cola, Barq’s root beer and Sunkist orange soda as the independent variables. To find the
chemicals in both the Mentos and soda that causes nucleation, it is necessary to find the
ingredients in both the Mentos and the soda.
Soda Ingredients
The ingredients used to produce Coca Cola, the control in the experiment, are: carbonated
water, high fructose corn syrup or sucrose, cane sugar, caramel color, caffeine, phosphoric acid,
coca extract, lime extract, vanilla, and glycerin. (Coca-Cola, 2010) The ingredients in diet Coca
Cola, an independent variable, are: carbonated water, caramel color, sweeteners (aspartame,
acesulfame-K), natural flavorings including caffeine, phosphoric acid, citric acid. Contains a
source of phenylalanine. (Diet Coke, 2010) The ingredients in Barq’s root beer, one of the
independent variables, are: carbonated water, high fructose corn syrup and/or sucrose, caramel
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Color, sodium benzoate (to protect taste) citric acid, caffeine, artificial and natural flavors,
acacia. The ingredients in Sunkist orange soda are: carbonated water, high fructose corn syrup,
citric acid, sodium benzoate, modified food starch, natural flavors, caffeine, ester gum, yellow
6, and red 40. All of the sodas (Coca Cola, diet Coca Cola, Barq’s root beer, and Sunkist
orange soda) have carbonated water, some form of sugar, and natural flavoring, which all could
contribute to the chemical reaction of nucleation.
Misc.
Diet sodas have been known to have a bigger reaction with Mentos than regular soda. The
geysers of diet sodas traveled about seven meters in length. Also, soda that didn’t have caffeine
in them had about the same size geyser as the sodas with caffeine. The size of the geysers
depends on factors that affect the growth rate of carbon dioxide bubbles. Diet Coke creates
more bubbles than regular Coke because the surface tension of the water is lower because Diet
Coke contains a sweetener aspartame. (Muir, 2008.)
Hypothesis
Based on these facts, it is hypothesized that the diet Coca Cola will have the tallest geyser
because of the lower surface tension due to the artificial sweetener, aspartame.
Design and Preform an Experiment
Materials:
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40 Mentos
10 Two Liter Coke Bottles
10 Two Liter Diet Coke Bottles
10 Two Liter Sunkist Orange Soda Bottles
10 Two Liter Barq’s Root Beer Bottles
1 Geyser Tube
The Reaction of Soda and Mentos
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4
1 Meter Stick
1 Ladder
1 Adding Machine Tape
1 Pen
1 Sharpie
1 Piece of Lined Paper
1 Hammer
10 Nails
Procedure:
1. Mark adding machine tape every ten centimeter with meter sticks for four meters.
2. Set up ladder to full height against a tree perpendicular to the ground.
3. Climb ladder with adding tape and nail the top of the tape to the tree with the hammer.
Make sure that the zero meter mark is touching the ground.
4. Nail adding tape every meter until the ground.
5. Take down ladder.
6. Place soda bottle thirty centimeters away from tape.
7. Place one Mento inside the geyser tube.
8. Take off cap of soda.
9. Screw geyser tube onto open end of soda tightly
10. Release Mento by pulling red lever.
11. Watch, measure, and record data of how high the geyser goes.
12. Repeat steps 6-11 ten times each for all four soda types.
Analyze and Draw a Conclusion
Table 1: Height of Geyser (m)
Trial
1
2
3
4
5
6
7
8
9
10
AVG
Coke (m)
4.2
3.45
2.8
3.1
2.5
3.4
2.9
2.6
3.1
1.8
2.985
Height of Geyser
Diet Coke (m)
2.7
3.35
4.3
4.1
3.9
3.1
2.95
4
4.5
3.7
3.66
Sunkist (m)
1.3
0.4
1.1
1.6
0.9
0.85
1.9
0.6
1.1
0.55
1.03
Barq's (m)
3.5
1
0.3
2.15
1.7
1.55
1.5
1.7
1.6
1.9
1.69
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Graph 1: Avg Height of Geysers
Average Heights of the Geysers
4
3.66 m
3.5
2.985 m
3
2.5
Coke (m)
Diet Coke (m)
2
1.69 m
Sunkist (m)
Barq's (m)
1.5
1.03 m
1
0.5
0
Graph 2: Heights of the Geysers
Height of Geysers
5
4.5
Height of Geyser
4
3.5
3
Coke (m)
2.5
Diet Coke (m)
2
Sunkist (m)
1.5
Barq's (m)
1
0.5
0
0
2
4
6
Trial
8
10
12
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Table 2: Confidence Intervals
Lower 95% Confidence Limit
Mean
Upper 95% Confidence Limit
1
1
1
Control - Coke
2.456
2.985
3.445
2
2
2
Diet Coke
3.226
3.66
4.094
3
3
3
Sunkist
0.691
1.03
1.369
4
4
4
Barq's
1.106
1.69
2.274
5
5
5
Graph 3: Confidence Intervals of Geyser Heights
95% Confidence Intervals of Geyser Heights
4.5
4
3.5
Height (m)
3
2.5
2
1.5
1
0.5
0
0
0.5
1
Control-Coke
1.5
2
Coke
2.5
Sunkist
3
3.5
4
4.5
Barq's
Table 3: P-values
p-values
Control-Coke
Diet Coke
Sunkist
Barq's
ControlCoke
1
0.013
2.868
0.0005
Diet Coke
Sunkist
Barq's
0.013336123
2.868
2.504
1
0.0005
5.656
0.0221
0.0221
1
1
2.504
5.656
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Conclusion
The reason for this project was to see which soda, Coca-Cola, Diet Coke, Sunkist, or Barq’s,
will create the highest geyser. Through a process called nucleation, the Mento reacts with the
soda and carbon dioxide bubbles form off of the Mento and get put to the side and forced out
through the top. Nucleation is boosted in Diet Coke because Diet Coke contains an artificial
sweetener called aspartame.
To test the problem, first, set up the ladder and tape the measure tape to a high surface. After,
take down the ladder and bring out all of the soda. Place one bottle of soda on a certain spot,
about 15-20 cm, away the measure tape. Put one Mento is the geyser tube and attach it to the
bottle. Release the tube and record the height of the geyser. Repeat this process until you have
finished all of your testing.
Based on the averages, the diet coke had a higher geyser when one Mento is put into it with an
average of 3.66 m high. The second highest average goes to Coca-cola with an average of
2.985 m tall. The third was Barq’s with an average of 1.69 m. And Sunkist was the last with an
average of 1.03 m.
If the data is collected in the same fashion and the same factors play a role in every trial, there is
a 95% confidence that the average geyser height of Coca-Cola will be between 2.456 m and
3.445 m. With the Diet Coke, there is a 95% confidence that the average will be between
3.226 m and 4.094 m. With the Sunkist, however, the confidence interval goes down
tremendously: between 0.691 m and 1.369 m. And Barq’s confidence interval is between 1.106
m and 2.274 m.
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The t test results for the variables supports the confidence interval conclusions. Becacuse the pvalue of Coke and Diet Coke is 0.013336123, or less than 0.05, the average height of Diet Coke is
higher than that of Coke. Also, because the p-value of Coke and Sunkist ≥ 0.05, the Coke had a higher
geyser than Sunkist.
Based on the data, the hypothesis is proven correct. The Diet Coke did have the highest geyser because
of boosted nucleation because of an artificial sweetener, aspartame. Sunkist and Barq’s did not live up to
the performance of Coke and Diet Coke.
The sources of error group 8 had to deal with was the wind. The wind would blow the adding machine
tape a little bit, even with it nailed to a tree. The will could also blow the geyser a little, which could
decrease some geyser heights. Also, some geysers were hard to measure by the naked eye. This could
throw the data off a little.
This project does not have much importance. But it is actually important in chemistry. In the chemical
industry, nucleation is used in the process of preparing metal powders that can serve as catalysts.
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References
Coca Cola Company (2010). Coca?Cola : Cherry Coke : Coca?Cola Vanilla : Ingredients &
GDAs - Coca-Cola GB. Retrieved December 2, 2013, from http://www.cocacola.co.uk/brands/coca-cola.html
Coca Cola Company (2010). Diet Coke Ingredients & Nutrition : Weight Loss & Diabetes Coca-Cola GB. Retrieved December 2, 2013, from http://www.cocacola.co.uk/brands/diet-coke.html
Coca Cola Company (2010). Fanta Orange : Lemon : Can & Bottle Nutritional Information Coca-Cola GB. Retrieved December 2, 2013, from http://www.cocacola.co.uk/brands/fanta.html
Muir, H. (2008, June 12). Science of Mentos-Diet Coke explosions explained - physics-math 12 June 2008 - New Scientist. Retrieved November 27, 2013, from
http://www.newscientist.com/article/dn14114-science-of-mentosdiet-coke-explosionsexplained.html#.UpTVsMSsim5
[Nucleation]. (2014, June 14). Retrieved from
http://www.scientificamerican.com/article.cfm?id=bring-science-home-coke-mentos
[Two Mentos Rolls]. (2012, February). Retrieved from http://www.couponcloset.net/wpcontent/uploads/2011/02/mentos1.jpg
Wikipedia (2013, November 30). Diet Coke and Mentos eruption - Wikipedia, the free
encyclopedia. Retrieved December 3, 2013, from
http://en.wikipedia.org/wiki/Diet_Coke_and_Mentos_eruption
[Nucleation]. (2014, June 14). Retrieved from
http://www.scientificamerican.com/article.cfm?id=bring-science-home-coke-mentos
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