Candy and Soda Teacher’s Guide:
By RT Tourek
1/31/08
Key Concepts
Nucleation: A phase transition located in a small region. In liquids, it can be seen with
the creation of a bubble or a crystal.
Surface Area: The measure of how much exposed area a given object has.
Nucleation is a phase transition. In this case it has to do with the carbon dioxide
in the carbonated soda. The surface of the Mentos contains little craters on the candy
shell, that when added to the carbonated Coke, provide sites at which the Carbon dioxide
(CO2) can be formed and released from the liquid. Because of the rapid gas production,
there becomes an imbalance between the pressure within the bottle and the pressure
outside of the bottle. In an effort to even this imbalance, the Coke bottle will try to expel
the gas out of the bottle. Liquid “fizz” is trapped between the different gas bubbles and
also gets sucked out of the bottle with the gas. This eruption will continue until all of the
carbonation in the bottle is gone or the binding sites on the Mentos are gone.
The greater surface area of the Mentos contained in a coke bottle, the more gas
will be produced because of the greater surface area. With more sites for nucleation to
occur, the more gas can be produced, creating in a greater pressure imbalance, and
resulting in a higher spurt of Coke from the bottle.
***Children should be broken up into groups of 3
Materials for younger children per group:
 3 Diet Coke bottles (8 oz, plastic bottles)
 5 Mentos
 5 Pixie Stixs
 5 sweet tart candies
 Bucket Tray
 Yard stick with inch or centimeter markings.
 Wide mouth funnel (large enough hole to fit the width of a Mentos/ sweet tart
candy)
 Plastic note card
Materials for the older children per group:
 3 Diet Coke bottles
 15 Mentos per group
 Bucket Tray
 Yard stick with inch or centimeter markings.
 Wide mouth funnel (large enough hole to fit the width of a Mentos candy)
 Plastic note cards (one per group)
 Magnifying glass
Students should gather into groups of three. Positions should be rotated every bottle
experiment where the every child has an opportunity to hold the measuring yard stick,
hold the funnel, and to pull the index card.
***Each Step should be reviewed as before the experiment is conducted so that there
everyone understands what they need to do and can ask a question if they do not
understand any point of the procedure.
Procedure for younger children:
1.) Take a Coke bottle and place it in the center of the bucket tray and take off the
cap.
2.) Place a note card on the top of the Coke bottle, and hold the funnel on the top of
the note card so that the card is the only obstruction in between the mouth of the
funnel and the mouth of the Coke can is the note card.
3.) Place the Mentos in the funnel.
4.) A student should hold a yard stick behind the Coke bottle and measure the height
of the Coke bottle.
5.) Remove the note card and allow for the Mentos to funnel into the Coke bottle.
After all of the candy is funneled into the bottle, quickly remove the funnel away
and move to a viewpoint that has your eye level on the plane of the coke bottle
top. This will allow you to see the actual height after the rise of the Coke.
6.) Allow for the complete reaction to occur before touching the coke bottle. Record
the height of the tallest point the Coke reached on the yard stick.
7.) Remove the Coke bottle after the reaction is complete and take it out of the
bucket, and place the bottle to the side.
8.) Repeat steps 1-7 with the Pixi Sticks and the Sweet Tarts.
Procedure for older children:
1.) Take a Coke bottle and place it in the center of the bucket tray and take off the
cap.
2.) Place a note card on the top of the Coke bottle, and hold the funnel on the top of
the note card so that the card is the only obstruction in between the mouth of the
funnel and the mouth of the Coke can is the note card.
3.) Place 2 Mentos in the funnel.
4.) A student should hold a yard stick behind the Coke bottle and measure the height
of the Coke bottle.
5.) Remove the note card and allow for the Mentos to funnel into the Coke bottle.
After all of the candy is funneled into the bottle, quickly remove the funnel away
and move to a viewpoint that has your eye level on the plane of the coke bottle
top. This will allow you to see the actual height after the rise of the Coke.
6.) Allow for the complete reaction to occur before touching the coke bottle. Record
the height of the tallest point the Coke reached on the yard stick.
7.) Remove the Coke bottle after the reaction is complete and take it out of the
bucket, and place the bottle to the side.
8.) Repeat Steps 1-7 with 5 Mentos and 8 Mentos and record the heights reached.
References:
Previous CH151 experiment
Candy and Soda
1/31/08
By R.T. Tourek
Before Experiment:
Circle the candy that YOU think will make the Coke go
the highest:
How high did each candy make the Coke with go up?
________
________
_________
Draw a picture of the Coke bottle after candy was added:
Candy and Soda:
1/31/08
By RT Tourek
Before the Experiment:
When any of the candies are placed into the Coke, do you think that
this is a physical or a chemical change?
What do you notice about the surface of the Mentos? Are They
Smooth or Rough?
During the Experiment:
What heights are measured when different numbers of Mentos are
dropped into the Coke? Create a graph below to see the relationship
between each.
_____________________________
2
5
8
Look at the Mentos in the bottle, what is surrounding the candy?
After the Experiment:
What are some possible limiting factors in this reaction for this
reaction to occur?