The

Guilford

Journal

Of

Chemistry

Volume 1 Number 1 October 19, 2007

This issue is dedicated to the investigation of the well-known Mentos Eruption.

Several discoveries are recorded for the first time in this issue, including:

Cold Mentos increase the height of a mentos eruption

A method for extremely long (1 minute) Mentos eruptions

A method for remote-controlled Mentos eruptions

A method for creating a “Mentos mist”

2

The Guilford Journal of Chemistry Dr. Harry Brielmann, Editor

The premier, state of the art venue for publication and broad dissemination of first-rate, fundamental research in

all of chemistry and Mentos Research.

Contributors to the Mentos & Diet Coke Experiment Effect of Surface Coatings:

Jennifer A Carly C

Different Carbonated Drinks and Mentos:

Zach B Ethan S

The Effect of Mentos Temperature:

Rachel C Emma S

Diameter of Nozzle Size:

Aaron D Travis D

The Effect of Diet Coke Temperature:

Justin H Delayed Reaction:

Stephanie M Mike M

Remote Control Eruption:

Paul Mulligan Jared Searles

Spray Effects and Nozzle Shapes:

Gabriella Necklas Kierstin Wall

Fruity vs. Minty:

Allessia Pascarella Johanna Penry

Nozzle Effects:

Taylor Smith Rosie Steffen

3

4

Introduction to this Issue

This first issue of the Guilford Journal of Chemistry includes groundbreaking discoveries in the field of

Mentos Eruptions.

In its simplest form, the Mentos eruption involves dropping Mentos candy into a soda (usually diet coke),

resulting in a foamy eruption, which can often be several meters in height.

The first widely viewed Mentos eruption occurred on September 14, 1999 on the David Letterman show,1

though earlier eruptions using other candies (with less spectacular results) had been used primarily by

teachers dating back to the 1980’s.2 In terms of scientiic research this field is still in its infancy, since

this area of research has almost no peer-reviewed published research results,3 although numerous

videos documenting riveting eruptions are available on the internet,4 and on commercial television.5

Several unverified explanations have been offered to explain the eruption6, usually focusing on the

physical shape of the mint (so-called nucleation sites), or on the various ingredients in the mint,

particularly gum arabic. It is important to note that none of these hypotheses have been scientifically

verified.

This journal represents the first attempts to scientifically investigate the mentos eruption. Several

previously unrepoted discoveries are documented in this journal.

Perhaps the most fascinating discovery was made by Cutler and Smith.7 This featured papers reveals

that that the height of a mentos eruption can be dramatically increased by freezing a mentos candy

prior to dropping it in the soda. Coupled with the predictable observation that heating a mentos candy

will increase the height of an eruption, this creates a bizarre result: the the height of a mentos eruption

is relatively high when the candy is cold, low when the candy is at room temperature, and then high again

when the candy is warm or hot. This discovery could in principle create world-record eruption heights

(the current record is 29.2 feet).

Another serendiptous discovery was made by Marsh and Moalli.8 While attempting to create a time-

delayed Mentos eruption, they chanced upon a method for sustaining an eruption for over 40 seconds.

More importantly, their graph suggests that this method could be applied to create eruptions that occur

for several minutes in theory, though there were some occasional reproducibility issues that will have to

be addressed.

Several of these papers are design-based, in which an eruption of a certain type is desired and executed.

Methods for creating several spectacular effects are published in this issue. Those interested in

creating a unique misting effect should read the work of Necklas and Wall.9 Those looking for both an

extremely high as well as a sustained eruption should turn to the work of Davis and Dillon.10

Space does not permit the higlighting of all articles. However, all of these investigations created

spectacular eruptions and we hope you enjoy reading about them

Dr. H. Brielmann

Editor in Chief

The Guilford Journal of Chemistry

5

References:

1. For an informative historical account of the Mentos Eruption, Speve Spanglers website is

recommended: (http://www.stevespanglerscience.com/experiment/00000109. Note that the original

Letterman Show Mentos Eruption may be viewed on the internet at

http://www.chem.uic.edu/marek/letterman0/video/mentos.htm.

2. For accounts of Mentos-like eruptions dating back to the 1980’s, see: Marek

http://www.rimmkaufman.com/rkgblog/2007/12/21/steve-spangler/

3. For example, the search term Mentos gives no results currently from polular scientific search

engines currently (2008), including PubMed or Google Scholar. Online material is available from

Scientific American (http://science-community.sciam.com/blog-entry/Sciam-Observations/Soda-

Fountains-Diet-Coke-Mentos/300004196) as well as detailed hypotheses by the Royal Society of

Chemistry (http://www.chemsoc.org/pdf/learnnet/classicdemos/mentosexplosion.pdf), but no

experiments were performed in either case to test their ideas.

4. In addition to YouTube, other websites have arrived that are dedicated to the mentos eruption. Of

particular mention is geysertube (http://www.geysertube.com/blog/), where one can view the Mentos

Eruption in ultra-slow motion.

5. For example, on the popular television series Mythbusters

(http://dsc.discovery.com/fansites/mythbusters/mythbusters.html).

6. Most literature on the Mentos Eruption cites the website of Fred Senese

(http://antoine.frostburg.edu/chem/senese/101/consumer/faq/mentos.shtml), however there are no

experiments performed or cited in support of these hypotheses.

7. Rachel Cutler and Emma Smith, Guilford Journal of Chemistry, Volume 1, Pages 6-12 (2007).

8. Steffi Marsh and Taylor Smith, Guilford Journal of Chemistry, Volume 1, Pages 13-16 (2007).

9. Gabriella Necklas and Kiersten Wall, Guilford Journal of Chemistry, Volume 1, Pages 33-35 (2007).

10. Aaron Davis and Travis Dillon, Guilford Journal of Chemistry, Volume 1, Pages 17-18 (2007).

6

Mentos Eruptions are increased by heating or Cooling the Mints. By Rachel Cutler and Emma Smith

Introduction:

Although there have been numerous experiments regarding the temperature of the soda versus

the height of the explosion; we have found that there are no apparent results of the effect of the

temperature of the Mentos in regards to the height of the explosion. 1Many people have conducted

these experiments because it is fun to watch, and because it is quite interesting as to what makes the

two create such a fantastic reaction. Most scientists say that it is the gum arabic that reacts with the

soda and produces the desired result2. There may have been experiments done regarding this, but we

have not found any results of those experiments. This had an effect on our experiment because we had

no previous results to compare our findings to. But in a way this was also good, because it was as if we

were the first ones who were discovering the effect temperature-changed Mentos had on Diet Pepsi.

The reaction between Coke and Mentos usually produces a good reaction3, and although our experiment

was modified it nonetheless produced good results.

Summary:

We wanted to see if the Temperature of the Mentos affected the height of the explosion when

dropped into a bottle of diet Pepsi. We froze Mentos, heated them up, and kept them at room

temperature to test the effects of each one, and then measured the height of the explosion of the diet

Coke.

Experimental Section:

Our goal was to find which temperature most affected the soda, and would therefore create the

biggest explosion. To do that we picked three different temperature areas to focus on: coldest, room

temperature, and the hottest. We put one package of Mentos in a freezer, another sitting out in the

room undisturbed, and another we wrapped in tinfoil and put on a hot plate. We then chose ten Mentos

and put them into a graduated cylinder on top of an open bottle of Pepsi. I walked away after I opened

the bottle of Pepsi, and Rachel ran away immediately after she dropped the Mentos into Coke. By doing

this I was able to get the first look at how the explosion went, and then both Rachel and I were able to

concentrate together once she ran away. We didn’t use any kind of nozzle because we were focusing on

finding how the temperature of the Mentos affects the height of the explosion. We considered our

negative control to be the neutral Mentos, which did produce a result, but not the one that we most

desired. Our positive controls were the Mentos we either heated or froze. Through this we were able to

compare the results of the positive controls to the results of our negative control. Overall, our

experiment was one based not on design, but rather upon finding an answer through an experiment that

produced results.

Experimental Procedure:

Materials:

~at least 3 bottle of Diet Pepsi

~at least 3 packages of Mentos

~2 meter- sticks

~a bin to catch all the sodas if you are conducting the experiment inside

1 http://chemistry.org/education/chemmatters.html

2 http://en. wikipedia.org/wiki/Diet_Coke_and_Mentos_eruption#Explanation.

3 http://en.wikipedia.org/wiki/Mentos#Mentos_and_soft_drink_reaction

7

~towels to clean up the surrounding area, again if you are conducting the experiment inside

~tinfoil

~a hot plate

~a freezer

~a thermometer ~a graduated cylinder which you’ll put your Mentos in

Procedure:

1. Gather all the materials that is necessary for the experiment at hand

2. Put 10 Mentos in a piece of tinfoil in a freezer, and keep them there as long as possible. Put another 10

in another piece of tinfoil and put on the hot plate; remember to keep checking the Mentos so they don’t

melt, or worse, start a fire. And finally, keep another 10 Mentos out to absorb the surrounding

temperature.

3. Set up your experimentation area; with your soda in the bucket, and at least 2 meter sticks tied or

taped together and put the 10 Mentos in the graduated cylinder.

4. Have one person open the bottle of Coke, and the other person line the graduated cylinder up with the

opening of the bottle. After the person who opens the bottle up is done with their job they should move

in front of the area so they can see how high the explosion is. The other person should drop the Mentos

into the bottle and run away as fast as possible so they don’t get wet.

5. Continue the experiment with the other two packages of Mentos and soda bottles, and do as many

experiments as possible so as to increase the validity of your results. Record your results as you go along

in your experiment.

Conclusion:

Through this experiment we were able to realize and discover the fact the temperature of the

Mentos does have an effect upon the height of the explosion. The Mentos that were heated to a degree

of 313K reached a height of about two meters, or 200 centimeters. The Mentos that were kept at room

temperature were about 303K; reaching a height of about 30 centimeters. Our biggest explosion by far

was that produced by the Mentos that were frozen to a degree of 263K, and the force that the

explosion hit the towel with was so great that it sprayed outwards. Because of that, we can only roughly

judge that the explosion reached a height of 350 centimeters. Our results showed us that the

temperature of the Mentos really does have an effect on the height of the explosion.

Although our experiment did produce valid results there were a few errors along the way. Those

included not all the Mentos falling into the Pepsi, and therefore not producing the full effect. We were

also not completely exact in judging the height of the explosion, most of the time we had to make a quick

estimate of where the peak of the eruption was. To make our results more valid we should have done

more tests, which would have given us more support in the deduction that the more extreme the

temperature the greater the eruption will be and more validity regarded the results we made.

Overall, we were able to discover what we had initially wanted to find out; the temperature of the

Mentos does have an effect upon the height of the eruption of the soda. However, to make our results

more valid and better understood we should have done more tests; we also should have done more

experiments because not all of the Mentos were dropped into the Pepsi which made the eruption results

differ. However, we can concur that height is affected by temperature, and we are positive that if

future tests were done regarding this, the scientists or whoever is conducting the experiment will find

the same results that we found.

8

0

50

100

150

200

250

300

350

He

igh

t o

f E

xp

lost

ion

(Ce

nti

me

ters

)

236K

303K

313K

Te

mp

era

ture

(K

elv

in)

Th

e E

ffe

cts

of

the

Dif

fere

nt

Te

mp

era

ture

s o

f M

en

tos in

Die

t C

oke

9

Sustained Mentos Eruptions. Creation of a 40 Second Mentos Eruption by Mike Moalli and Steffi Marsh

Summary

We tested coated mentos to see which coating would create the longest diet coke and mentos eruption.

After testing our control, oil, sugar, molasses, and honey, we concluded that honey made the longest

eruption of 40.28 seconds.

Introduction

There is little to no information about how to delay the mentos reaction or how to make a prolonged

mentos eruption. However it is believe that what causes the mentos and diet coke reaction is not a

chemical reaction but a physical one. The gellan gum and gum arabic in the mentos dissolve and breaks

the surface tension. This disturbs the water connection, so that it takes less work to expand and form

new bubbles¹. Each mentos candy has thousands of tiny pores all over its surface. These tiny pores

function as nucleation sites for carbon dioxide bubbles to form. When the mentos enter the soda,

bubbles form all over their surface. They quickly sink to the bottom, causing carbon dioxide to be

released by the carbonated liquid with which they come into contact along the way. The sudden increase

in pressure pushes liquid up and out of the bottle².

Experimental Section

Our original experiment was to design a delayed mentos eruption. In order to do this we decided to coat

the mentos in a variety of different substances to get the desired affect. Some of these substances

including: honey, oil, molasses, sugar, salt, and others. We would coat three mentos in each of the

substances and drop them into a small twelve ounce bottle of diet coke and then time how long the

reaction was delayed compared to the control (three mentos that were not covered in any substances).

After completing this we found that none of the substance had any significant delay in the reaction,

however we notice that different substances gave a longer reaction. Using this newfound data we

10

retested some of the substances and timed how long each reaction was. After completing this we found

that honey worked the best for creating a longer reaction.

Results

control 7.17

oil 7.89

sugar 10.32

molasses 30.18

honey 40.28

Conclusion

After conducting our experiments we have come to the conclusion that honey coated mentos work the

best for a prolonged mentos and diet coke reaction. However our original experiment was inconclusive in

finding a substance that delayed the mentos reaction. But in the progress of trying to find a substance

that would delay the mentos reaction we found that some substance prolonged the mentos reaction by as

much as 30 seconds. Some follow up experiment may include: the amount of honey used in covering the

mento, break down honey into pure substance and seeing which substance in the honey is the main

component in prolonging the reaction, and using different kinds of honey. Although we did not achieve

our intended goal of making a delayed mento reaction, we believe that we have found something more

useful and more fun overall.

Materials

1. 2 ounces of the following at room temperature:

a. Sugar

b. Molasses

c. Honey

d. Oil

e. Water

0

5

10

15

20

25

30

35

40

45

reaction time (in

seconds)

control oil sugar molasses honey

types of coatings

Effects of Coatings on Mentos

control

oil

sugar

molasses

honey

11

2. 5 pieces of string each about 15 centimeters long

3. 5 two liter bottles of diet coke

4. At least 50 regular mint mentos

5. Tongs

6. Drill (to make a holes through the mentos)

7. Pencil or pen and paper (to record results)

8. Stop watch

9. Towel

Experimental Procedure

1. Take all of the mentos and drill holes though them.

2. Put them in groups of ten and tie ten mentos on each of the five strings. Make sure they are tied close

together so there is room to hold the string before you drop it into the bottle.

3. Make sure to do this experiment outside where it’s okay to make a mess of diet coke and mentos.

4. The first test will be the control so there is no need to coat this sting of mentos in anything.

5. Have your stopwatch ready because the string of mentos needs to be dropped into the bottle as soon as

it is opened (to keep the carbon in) and the explosion will begin as soon as the string is dropped.

Remember, you are testing how long the entire explosion takes to compare it to the other coated

mentos.

6. Open the bottle of diet coke and immediately drop the string of mentos into it. Stand clear at least

three feet to prevent being soaked in diet coke.

7. Once the diet coke reaction has stopped fizzing out the top, record your results.

8. This time you’re going to be testing the honey. Dip the string of mentos into the honey and use the tongs

to make sure there’s a nice thick coat of honey each of the mentos. Make sure to use a new bottle of

diet coke and a new string of mentos each time you perform a trial because if either of them have been

used for a previous trial, there will be no diet coke eruption.

9. Now repeat steps 4-7 with molasses and then repeat the same steps with oil. Then skip to step 10.

10. When you’ve finished testing the control, honey, molasses, and oil, now test the sugar. Quickly dip your

last string of mentos into the water before you coat it in the sugar. Again, repeat steps 4-7 with the

sugar mentos, and then skip onto step 11.

11. Once all the experiments are completed, use the towel to clean up any mess if needed. Don’t forget to

recycle the diet coke bottles.

References

1. http://en.wikipedia.org/wiki/Diet_coke_and_mentos

2. http://www.stevespanglerscience.com/experiment/00000109

12

Remote Control Mentos Eruption by Paul Mulligan and Jared Searles Manuscript in preparation.

The Effect of Nozzle Size on the Height of Mentos Eruptions. Discovery of a method for thin, sustained eruptions

by Aaron Davis and Travis Dillon

The purpose of this experiment is to see if we use different nozzle sizes if it would affect the size of

the eruption of diet coke when mentos is put into it. We believed that the smaller nozzle size we used

the higher the eruption would go. When we conducted our experiment we were correct. When we placed

3 mentos into a 12 ounce diet coke bottle with no cap the eruption only went 8 centimeters high. Except

when we put 3 mentos into a 12 ounce diet coke bottle with a 3 millimeter nozzle that the eruption went

over 2 meters. We also tried with a nozzle size of 11 millimeters but the height of the eruption only

went 61 centimeters.

When we conducted studies on the height of diet coke eruptions when mentos is put into the coke we

found out that the smaller nozzle size the higher the eruption and the longer the eruption will last. With

a larger nozzle size the eruption will not go as high nor as will the eruption last as long.

In our experiment we conduct an experimental procedure that focused on how different nozzle sizes of

diet cokes will affect the size of eruption when mentos is put into the diet coke. We used 3 diet cokes

with no caps, 3 diet cokes with 3 millimeter nozzle, and 3 diet cokes with 11 millimeter nozzle. We placed

3 mentos in each diet coke and measure the height of the eruption using meter sticks.

In our experiment we found out that the smaller nozzle size the higher the eruption will go. We came to

this conclusion because when we used a nozzle size of 3 millimeters we got our highest eruption of over 2

meters. The average of the eruption with a 3 millimeter nozzle was over 2 meters. When we did not use

a cap at all the average height of the eruption was 6.7 centimeters, the lowest eruption we had. When

we used a middle size nozzle of 11 millimeters we got a larger eruption then using no cap but a smaller

eruption when we used a 3 millimeter nozzle.

Procedure:

1. Gather materials

2. Take 3 12 ounce bottles of diet coke and open cap

3. Place 3 mentos in each of the three bottles

4. Measure the height of the eruption by using a meter stick

5. Record the data you collected

6. Repeat step 2

7. Take a drill and drill a 11 millimeter hole into all three caps

8. Repeat steps 3, 4 and 5

9. Repeat step 2

10. Take a drill and drill a 3 millimeter hole into all three caps

11. Repeat steps 3,4, and 5

http://eepybird.com/science.html

http://eepybird.com/How%20To%20Do%20It%20Yourself!.pdf

13

14

Caps with 8mm holes.

Caps with 4mm holes.

NOZZLE DESIGNS CREATE SPRAY EFFECTS FOR MENTOS

ERUPTIONS Taylor Smith and Rosie Steffen

Introduction: “The Mentos and Diet Coke Experiment” is caused when Mentos mint candies are dropped

into a bottle of a carbonated substance. The result is a jet of soda which spews from the neck of the

bottle. The reaction is due to the rapid expanding of carbon dioxide bubbles on the surface of the

candy. i

Experiment: In order to create a Mentos eruption, one releases a number of Mentos mint candies into a

bottle of Diet Coke. When the two elements of the experiment combine, they result in an explosion

consisting of the carbon dioxide “fizz” of the Diet Coke. In this particular

experiment, holes of varying sizes and patterns were drilled into the caps of the

Diet Coke bottles prior to the release of the Mentos, thus causing the height and

spray patterns to also vary. To enhance the height of the results, the holes drilled

in the bottle caps must be smaller. When designing the experiment, drilling holes in

a circular formation, created a fountain effect with the “fizz,” or by arranging the

holes in a line formation, the “fizz” erupts in a similar fashion. In order to create a

more horizontal effect of the spray, the holes should be drilled at an angle,

pointing as much towards the opposite side of the bottle as possible. The holes

cannot be drilled on the side of the cap itself; because of they would directly

interfere with the cap’s ability to hold onto the bottle, thus resulting with

projectile qualities. In this particular experiment, the hole which created the highest and longest lasting

spray effect was a single hole in the center of the cap drilled with a 4mm drill bit.

Conclusion: In this experiment, the best results were the single, 4mm sized

hole because the carbonation was so concentrated to a single are and

therefore resulted in the highest height (6.09m or 20 ft.) and the hole

which was drilled at an 8mm resulted in

the lowest height (.9144m or 3ft.). This

experiment could be modified for

better results by applying further

variations to the nozzle designs to better

shape the eruption and thus increasing

the number of eruptions in order to achieve the desired effect.

15

Experiment Procedure: Gather materials: 1 two liter bottle of Diet Coke (otherwise unflavored for best results), 1

package of at least ten mint Mentos, 12 cm of dental floss (or other string), a 5 cm (at least) thick piece

of plywood, a 5cm roofing nail, a 4mm and 8mm drill bit, a power drill and two or three meter sticks.

Step 1: Using the roofing nail, score ten Mentos by slightly applying pressure to the middle of the

Mentos candy. Create a depression in the candy so that the drill bit will not slip off the Mentos when

drilling. Do this for all ten candies.

Step 2: Set up your drilling station by laying the plywood down. Ready your ten scored Mentos and

begin to drill through them. Start by applying slight pressure downward on the candy while slowly drilling

and only slightly increasing the drilling speed once the hard sugar coating is broken though. The speed

increase after the coating, is necessary because the inside of the candy is gummy and a faster speed is

needed to work through it. The candy might crack in half, do not use these because they could break

apart during the experiment and cause a premature eruption. Repeat this process for all ten Mentos.

Step 3: Drill the desired design in the bottle caps. It is better to collect other bottle caps and

drill those because if the caps are removed from the test bottles, the carbonation in the soda will

escape. Drill the desired designs in both diameters but on separate caps so that the height will vary.

Remember that fewer holes in the caps create a greater concentration and therefore create the best

results.

Step 4: String your Mentos on the dental floss. Once you have completed that, take the string

and thread it through one of the central holes in the drilled bottle caps.

Step 5: Stand the three meter sticks end to end, vertically. Secure them as you see fit (duct

tape is the best). Attach them to the Diet Coke bottle in the same fashion so that they will record the

height of the eruption.

Step 6: Open your test bottle and quickly remove enough soda so that when you screw on the

drilled cap, holding the string of Mentos, the soda will not touch the candy resulting in a premature

eruption. Once the drilled cap is securely on, hold the string of Mentos vertically and make sure it will

not get stuck anywhere on the cap when it is released.

Step 7: Before letting go of your sting, have a partner stand nearby to take pictures of the

eruptions because this is a more accurate method of recording the eruption height.

Step 8: Release your string and run!

(Repeat the procedure as many times as you wish, try varying the number of Mentos to achieve different heights.)

16

17

The Effect of Soda Type on the Height of Mentos

Eruptions By Ethan Shore and Zack Brown

Summary: We tested the effect of different soda types on the height of mentos based

eruptions in 2 liter soda bottles. We did 2 trials for each soda; Diet coke had explosions of .6 and 1.1m.

Coke explosions of .1 and .15m . Sprite had explosions of .45 and .57m. Sprite zero had explosions of 1.1

and .95m. Sprite zero had the highest average explosion, with an average of 1.025m.

Introduction:

While many people have tried the Diet Coke and Mentos eruption experiment

before, not many people have attempted to test different soda types with Mentos. However, the

phenomenon was started by Steve Spangler, a science teacher, which got an explosion with Diet Coke and

Mentos reaching 5.5 meters¹. He determined that as the rather heavy candy falls to the bottom of the

bottle, carbon dioxide is released and the suddenly increased pressure pushes the liquid out of the

bottle¹. One science class also attempted testing 44 different soda types on Mentos eruptions².

Experimental:

We tested each soda by opening the each bottle of soda, and then placing 5 Mentos inside

the soda bottle, and then waited for the eruption. There were meter sticks behind the soda, so we could

measure each eruption. We used 5 Mentos for each trial.

Results:

Conclusion:

Based on our results, Sprite Zero causes the highest Mentos eruption with an

average eruption of 1.025m. Diet Coke had the second largest explosion with an average of .85m. Sprite

had the 3rd largest explosion, with an average of .51m. And Coke had the smallest average explosion, with

an average of .125m.

The Effect of Mentos on Different Soda

0

20

40

60

80

100

120

Diet

Coke

Coke Sprite

Zero

Sprite

Soda

Heig

ht

Trial 1

Trial 2

18

This data was not 100% conclusive. During some of our trials, it was not clear whether all 5

Mentos made it into the bottle before the explosion occurred. Another factor lessening the

conclusiveness of the results is the fact that after we dropped the Mentos in, we had to move out of the

way very quickly. Sometimes, my hand partially hit an explosion, perhaps causing the height to drop. The

results of this experiment were somewhat valid.

Experimental Procedure

Step 1: Gather 2, 2 liter bottles of Sprite, Diet Coke, Coke, and Sprite Zero.

Step 2: Gather 40 Mentos, and a test tube (small enough for Mentos to fit in, large enough for

them to fall out).

Step 3: Take the plastic bin from the front of Dr. B’s room, and place it at one of the back

tables.

Step 4: Tie 2 meters sticks together behind it, making sure that the sticks are straight.

Step 5: Place a bottle of Diet Coke in the bin.

Step 6: Place 5 Mentos in the test tube.

Step 7: Open the bottle.

Step 8: Drop the Mentos in the bottle.

Step 9: Record the height of the explosion in your data.

Step 10: Repeat steps 5-10 for Diet Coke once more, and each other soda twice more.

References:

¹http://sciencecentered.blogspot.com/2007/04/mentos-and-diet-coke-geysir.html

²http://www.geysertube.com/blog/

19

How the Coatings of Mentos affects the size of the Mentos Eruption by Carly Clark and Jenn Agamie

Introduction: For our experiment we decided to test the different effects of mentos coatings on diet

coke to see the different heights of eruptions. To test our theory we used a control, which was the

regularly coated mentos, mentos without any coating, and mentos drenched in dish soap. After three

trials we were able to clearly see that the regularly coated mentos had the best eruption by far.

Summary: Throughout our experiment we concluded that the non-coated mentos had the worst height.

The average height in centimeters after three trials was only 33.33 cm. This shows that there was

hardly any eruption at all. The mentos soaked in dish soap averaged to be 58.33 cm, which is better than

the non-coated but still not superb. Finally, we were able to test the regular mentos and received an

average height of 230 cm. We made sure to use exactly ten mentos per liter of diet coke so that we had

a constant throughout our experiment.

Experimental Section: The design of our experiment was to see what actually made the mentos in the

diet coke to erupt. After several ideas were tossed around we decided to see if the coating had anything

to do with the eruptions. In order to test this idea we de-coated ten mentos and covered ten more in

Dial dish soap. Then we gathered ten more mentos and left them with their regular coating. Instead of

stringing the mentos onto a wire and dropping them into the diet coke bottles we decided to place all ten

of them into a graduated cylinder and hold a thin piece of paper over the opening. We flipped the

graduated cylinder upside down so that the opening covered with paper was lined up to the top of the

diet coke bottle. We tried to let as little carbonation out of the bottle as possible, so that there was

more of a reaction.

Procedure:

1. First, we gathered our materials, which consisted of a graduated cylinder, 3 liters of diet coke, and 2

packages of mentos. We also used dial dish soap, a beaker, and thin pieces of paper, two-meter sticks,

and a bucket.

2. Then we made three piles of ten mentos. One set we covered in soap, then next set was regular, and

the third we soaked in a beaker full of hot water so that the coating would dissolve.

3. After the mentos were ready, we placed one liter of diet coke in the bucket so that when the eruption

occurred soda wasn’t sprayed everywhere.

4. Next, we taped two-meter sticks together and tied them around the diet coke bottle so that we were

able to see the height of the eruption.

5. Then one of us held the graduated cylinder upside down above the top of the bottle. While the other

person unscrewed the cap.

6. As soon as the cap was unscrewed the person holding the graduated cylinder moved the paper and

released the mentos into the diet coke.

7. We made sure to stand far enough from the eruption so that we wouldn’t get soaked in soda, but close

enough to see the height of the eruption.

8. Once each different type of mentos underwent the experiment we recorded our data into a table.

9. We performed the experiment two more times. Each time recording our data to make sure the height

was accurate. We then averaged the height of the different mentos to see the results as one.

20

10. Once each trial was through, we cleaned our station and compared our results to our hypothesis.

Conclusion: After having tested our experiment many times we came to a conclusion that the mentos

with the regular coating had by far the best eruption. While it averaged in 230 cm the other two only

went up to 58.33cm (soap), and 33.33 cm (non-coated). As we thought, there is something in the coating

of the mentos that effects the eruption. During our experiment we were very much in awe to see that

the two mentos that were changed had such a low height.

References: 1.”Mentos Geyser.” Making Science Fun. Feb.10, 2008.

http://www.stevespanglerscience.com/experiment00000109.

2. “Diet Coke and Mentos Eruption.” Wikipedia, the Free Encyclopedia.Feb. 10,2008

http://en.wikipedia.org/wiki/Mentos-eruption.

3. ‘How to Make a Soda Bottle Volcano.” Extreme Diet Coke and Mentos Experiment, Wikihow. Feb.11,

2008

http://www.wikihow.com/make-a-soda-bottle-volcano.

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Different Coatings

The Effects of Different Mentos Coatings in Diet Coke

Series1

Series2

Series3

21

Warm Soda has a dramatic effect on the Height of a Mentos Eruption

by Justin Husted

While numerous experiments have been done with the coke mentos eruption, sometimes called the

coke mentos geyser or rocket, very few have tried testing the effects of the temperature of soda

before adding the mentos. Some brave experimenters have come to the conclusion that the reaction

rate appears to double for every 10 degrees Celsius that you heat the diet coke. Similarly for every 10

degrees that the soda is cooled (or frozen) the reaction power and height is cut in half. 4 Also according

to www.stevespangler- science.com, the temperature of the soda greatly affects how much force and

height the geyser of soda fizz will shoot up to.5 My goal is to duplicate their experiments in an attempt

to find if the temperature of the diet coke actually affects the height of the mentos eruption.

The Experiment:

By submerging bottles of coke into different water temperatures, we can safely control the

temperature of the soda inside. The three temperatures being used in this experiment are cold, (262 K)

room temperature (298 K) and warm diet coke (approximately 308 degrees K). Using eight mentos in

each bottle, they will be set up to erupt and see which yields the biggest eruption.

Summary of findings:

The results of the experiment were clear and as expected. The coldest coda resulted in the small

and shortest eruption of diet coke. The room temperature soda had expected results and was a relative

increase from the cool soda. The warm diet coke’s results sky-rocketed. Of the two warm test trials,

both blast the coke into the air with a large amount of force, resulting in an average height more than

double what the room temperature soda achieved.

Conclusion:

At the conclusion of this experiment I found that, as expected, the warmest soda temperature

produced the biggest results of the three. The coldest soda temperature barely erupted out of the

bottle. The cold soda was submerged in water measured at 263 degrees Kelvin. After putting in eight

mentos, the following eruption resulted in about 20 centimeters of height. The next largest was the

soda that was left in the classroom for two days to ensure it was the average temperature of the room.

The temperature was measured at 298 degrees Kelvin. The resulting eruption was approximately one

meter exactly. (100 centimeters). The final trial was of the warmest soda was that which was heated in

water measured at 308 degrees Kelvin. The resulting reaction resulted in an eruption of 300 centimeters

(three meters). By the results of the data, it is easily safe to conclude that the warmer the diet coke

temperature, the more height the eruption gained.

Experimental Procedure:

The following steps will lead to the exact duplicate of the above experiment.

4 Username: “Labmonkey” Yahooanswers.com January 10

th, 2008

5 www.stevespanglerscience.com, mentos and soda temperature.

22

1) Obtain materials, needed is: three 2 liter bottles of diet coke, exactly 24 mentos candies, a

thermometer, meter sticks, and glass cylinder containers to house hot and cold water.

2) Submerge one sealed bottle of diet coke into a cylinder of cold water, measured at 262 degrees Kelvin.

Leave in for at least ten-twenty minutes.

3) Submerge a second bottle into warm water. Use the thermometer to measure the temperature of the

water to 308 degrees Kelvin. Leave in for ten-twenty minutes.

4) The third and final bottle should be left in normal room temperature conditions (approx. 298 degrees

Kelvin)

5) Set up a measuring system of at least two meters sticks in a container to catch the spraying coke. Tape

or string should be used to attach two sticks together.

6) Using a graduated cylinder to house eight mentos, un-attach cap of the first bottle and drop mentos

inside, stand back, observe and measure height using meter sticks.

7) Repeat step six for the remaining two bottles of diet coke. Use exactly eight mentos each time and

record each height in a table for future reference.

8) Graph and conclude data.

23

Creating a “Misting Mentos Eruption”

By Gabriella Necklas and Kiersten Wall

Summary: For our experiment we tested how the shape of the opening that the soda sprays through

affects the height of the geyser. Our goal was to determine which nozzle created the greatest height.

From our experiment we were able to conclude that the smaller the hole the higher the geyser created.

We were also able to see that a circular shape works better than a slit in the cap does.

Introduction: In the field of Mentos eruptions there is still some debate over how the reaction occurs.

However, there is one relatively accepted reason for the reaction. “When you drop the Mentos into the

soda, the gelatin and gum arabic from the dissolving candy break the surface tension. This disrupts the

water mesh, so that it takes less work to expand and form new bubbles. Each Mentos candy has

thousands of tiny pits all over the surface. These tiny pits are called nucleation sites - perfect places

for carbon dioxide bubbles to form. As soon as the Mentos hit the soda, bubbles form all over the

surface of the candy.” ii It is also well noted that a substance under pressure that is forced through a

small hole will go higher than the same substance through a substantially larger hole. This is how we

came to the hypothesis that our small hole would produce the largest geyser.

Experimental Section: For our experiment we conducted two trials. Each trial followed the same

procedure, our goal was to try and get the most accurate results possible. We dilled a hole into the

center of each mento and then strung 10 mentos for each nozzle type. We then pulled the other end of

the string through the nozzle so that the mentos would hang below the nozzle and into the bottle while

we had about a two inch portion of string to hold onto until the designated time for eruption. We also

attached two meters end to end and staked them into the ground behind our soda bottles in order to

measure our eruptions. Once all of these preliminary steps were taken care of we screwed on the nozzle

that was being tested and let go of the string in order to release the mentos into the Diet Coke.

Results Section:

24

Nozzle Type Trial 1 Trial 2

Control 1 meter 1.2 meters

Small Hole .7 meters About 3.5 meters *

Straw .5 meters 2 meters

Small Slit .2 meters 1.5 meters

Measurements have been rounded. *Our measuring device only went up to two meters, for this

measurement we had to estimate its final height.

Our first trial is significantly different than our second trial for all of our experimental nozzles because

of a malfunction we had with our release cord. For our second trial we were able to fix the problem and

our results are much larger because of it.

Conclusion: Our results conclusivly show that the small hole is the optimum nozzle size to produce a

large geyser. The small hole went 1.5 meters higher than its closest rival, the straw. Even though the

straw and the small hole’s openings had the same diameter they both had drastically different results,

we believe that the length of the straw affected the height of the geyser. Also while the small slit did

manage to go higher than the control, by only .3 meters, we were able to see that at a certain point the

hole becomes too small for the geyser and it has the affect of creating a much shorter eruption. We

noticed during our trial of the small slit that more of the soda was coming out in a mist like fashion

creating a much shorter and less impressive eruption. For follow up experiments it would be a good idea

to try nozzles of different lengths. For instance cutting a straw into three different lengths in order to

see if it was really the length of the straw that caused it to create a shorter geyser than the small hole.

Another possible follow up experiment would be to have holes that gradually increase in diameter to

check if the small slit really was too small and if the small hole really is the optimum size.

Procedure:

1. Gather 8 two liter bottles of Diet Coke, 4 boxes of Mentos, string, a drill, a straw, and a pastry nozzle

used to make ribbon like lines.

2. Drill a ¼ inch hole into a soda cap, this will be the small hole nozzle.

3. Drill another ¼ inch hole into another soda cap and insert the straw into the hole so that when the cap is

screwed onto the bottle the strawl will stick up on the outside. This will be the straw nozzle

4. Now drill a hole into another cap that is large enough to fit the pastry nozzle. Then insert the pastry

nozzle into the hole so that when the cap is screwed onto the bottle the nozzle is on the outside. Hot

glue the pastry nozzle into place so that no liquid can escape. This will be the small slit nozzle

5. Now drill a hole into the center of 80 Mentos, this will be enough for both trials on each nozzle.

6. Tape two meter sticks end to end and stake them into the ground so as to measure the eruptions.

7. Place an open Diet Coke infront of the meter sticks.

8. String 10 drilled Mentos and hold them so that only the bottom two Mentos are in the neck of the

bottle. Count down from three and drop the Mentos into the soda. Record the eruption, this will be your

control.

9. Repeat step 8 for the second trial of the control.

10. Now string another 10 Mentos. Run the top of the string through the small hole and screw the small hole

nozzle with the mentos dangling beneath it onto a new Diet Coke bottle, make sure that the Mentos will

not touch the diet coke, you may need to pour out some soda. Place the ready bottle infront of the

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meter sticks and count down from three then drop the Mentos into the soda and record the

eruption.This will be your small hole trial.

11. Repeat step 10 for the second trial of the small hole.

12. Now string another 10 Mentos and run the top of that string through the straw nozzle. Screw the nozzle

onto a new Diet Coke bottle so that the mentos hang below it, make sure they do not touch the soda, you

may need to pour some soda out. Place the readied bottle infront of the meter sticks and count down

from three, then drop the mentos into the soda and record the height. This will be your straw trial

13. Repeat step 12 for trial two of the straw nozzle.

14. String another 10 Mentos and run the top of the string through the small slit nozzle. Screw the small

slit nozzle onto a new bottle of Diet Coke so that the mentos hang inside the bottle, make sure they do

not touch the soda, you may need to pour some soda out. Place the bottle infront of the meter sticks,

count down from three and let the Mentos fall into the soda. Record the geyser, this will be your small

slit nozzle trial

15. Repeat step 14 for trial two of the small slit.

16. Clean up the workspace.

Gabriella Necklas and Kierstin Wall

i “Diet Coke and Mentos Eruption,” http://en.wikipedia.org/wiki/Diet_Coke_and_Mentos_eruption

ii http://www.stevespanglerscience.com/experiment/00000109