COKE AND MENTOS EXPERIMENTS Mallory Griffin Cary Academy
ABSTRACT The purpose of this experiment was to test whether or not the temperature of Coke affects the height of the Coke and Mentos geyser. The experiment was done with fruit and mint Mentos. The hypothesis for the experiment is that the Mint Mentos will make a bigger geyser because the mint taste is on the inside so there is not a layer blocking the coke from the nucleation sites and the geyser will be bigger when the Coke is cold. The experiment was done outside. The Mentos were put into a test tube and when it was time, they were poured into the Coke. The geyser was measured when it came up into the air. This was done with mint Mentos and Fruit Mentos. The hypothesis was incorrect. The geyser with cold Coke only went an average of 57.5 cm but when the Coke was hot, it went an average of 220 cm.
INTRODUCTION The purpose of the experiment was to test whether or not the temperature of Coke effects how big the geyser is when a Mentos is added. The question was that Mentos in Coke would make a bigger geyser with hot, cold, or room temperature coke and will it work better with Mint or Fruit Mentos?
Coke is a liquid soda. The bottles of coke contain a volume of 2 liters of Coke. There are 840 Calories in the entire bottle. In the bottle there are 39 g of sugar. The Coke is all black and at the top of the Coke there are little bubbles especially when it is shaken up. When coke is shaken it starts to fizz. The mint Mentos has 10 calories in each Mentos and there are 14 Mentos per container. The Mentos are hard to crush but they are chewy after they are bitten. The Mentos are white on the inside and out. When the Mentos are crushed, they are powdery and the powder comes off. It feels rough when it is crushed and it smells like a mint. The fruit Mentos are just like the Mint Mentos. They are 10 calories each and 14 Mentos come in each container. They are hard but chewy
when they are chewed. On the outside, the Mentos are yellow and on the inside they are white. When the Mentos is crushed, it has a chalky feeling and it smells a lot like lemons because it is fruit flavored. When the Mentos is crushed, the powder from the inside of the Mentos comes off very easily. It is almost like dust that is on the Mentos. The Mentos kind of feels like sandpaper after it is crushed because lots of the pieces of Mentos have been broken up into lots of different pieces.
When a Mentos is dropped into coke, bubbles form around it which makes it explode into a geyser. Because there are tiny pits called nucleation sites on the Mentos, they make a bigger geyser in coke than other candies. The bubbles that form around the Mentos rise to the top and create the geyser. The Mentos sink to the bottom of the coke but eventually all of the gases are released and it makes a big fountain of coke.
Candy dissolves in someone's mouth because of the saliva in the mouth and it turns into liquid like the saliva. When the, soft drink is bubbly, it is because of the carbon dioxide that is added to it. There is Carbon Dioxide that is in the soft drink. A mixture is a mixture of two or more liquids, gases, or solids. Coke is a mixture because it is not made of just one thing. Lots of things are combined to make coke taste and look the ways it does. Mentos is also a mixture because it is not made of just one thing, it is made of many. If an object has a low temperature, it is cold. If coke is left in the refrigerator for a long time it is cold and has a low temperature but when the coke is left in the incubator, it becomes hot and has a high temperature.
The hypothesis for this experiment is that the Mint Mentos will make a bigger geyser because the mint taste is on the inside so there is not a layer blocking the coke from the nucleation sites. The fruit Mentos have a layer of wax on them so it is hard for the Coke to get to the Mentos. The hypothesis for the experiment is also that the cold Coke will make a bigger geyser when Mentos are added because when two things are the same temperature, nothing will happen but if they are different temperatures, something will happen and the Mentos and cold Coke are different temperatures.
MATERIALS & METHOD
6 bottles of Coke
3 packs of Mint Mentos
3 packs of Fruit Mentos
Test Tube
Meter Sticks
Small piece of paper
Incubator
Refrigerator
Timer
For the experiment, first a bottle of Coke was put in the incubator for 1 hour and another bottle of Coke was put in the refrigerator for 10 minutes. The incubator is 40 0C and the refrigerator is 2 0C. When the Coke in the refrigerator is done, it will be taken outside and opened up. The Coke bottle was put in the grass in an opened area. Five Mint Mentos were put in the test tube and turned upside down. The piece of paper will be put on the opened side of the test tube so the Mentos won’t fall out. When the test tube and paper were put over the opened part of the coke bottle, the paper was removed and the Mentos fell into the coke. When the Mentos fall in, back up because the Coke goes everywhere. This was repeated with hot and room temperature coke and was also done with fruit Mentos. The Coke and Mentos geyser was measured with a meter stick. The control for the experiment is room temperature coke with Mint Mentos added. The independent variable is what temperature the coke is and the dependent variable is how high the geyser is with Mentos added.
The second experiment was to see which type coke product makes the biggest geyser with Mint Mentos added? Coke, Diet Coke, and Coke Zero were the types of coke products used. First, a bottle of Coca-Cola will be opened up and 5 Mint Mentos will be put into a test tube. A small piece of paper will be put on top of the open coke bottle and the test tube will be put upside down on top of the paper. When the paper is removed,
the Mentos will fall into the coke. The height of the geyser will be measured in Meters. Once this is done, the same thing will be done with Diet Coke and Coke Zero. This will be repeated for each type of coke once. The height of each geyser will be measured and recorded.
The purpose of the third experiment was to see if the amount of coke used will effect how big the geyser is with Mint Mentos added. First, I will do the Mentos geyser with the entire bottle of coke and measure how big the geyser is. Then I will take another bottle of coke and pour out one liter. The geyser will be done with one liter of coke. Finally half of a liter which is equal to 500 milliliters will be used for the geyser and will be measured. All of the experiments will be done twice. I will use 5 Mint Mentos for each geyser.
Figure 1: Diet Coke and Mentos Geyser
RESULTS & DISCUSSION
Height of Geyser (cm)
300 250 200 150 100
50 0 Hot
Cold
Room Temperature
Hot
Cold
Mint
Mint Mint Fruit Fruit Temperature of Coke and Type of Mentos
Room Temperature Fruit
Coke Leftover (mL)
Figure 2: Height of Geyser 900 800 700 600 500 400 300 200 100 0 Hot
Cold
Room Temperature
Hot
Cold
Mint
Mint Mint Fruit Fruit Type of Mentos and Temperature of Coke
Room Temperature
Fruit
Figure 3: Coke Leftover
In the first experiment, the Coke was made different temperatures. After the experiment was done, the height of the geyser was averaged. The Coke that was leftover in the bottle was poured into a beaker and measured. The first graph is a graph showing the average height of the geyser when 5 Mentos were put into it. Fruit Mentos and Mint Mentos were both used for the experiment. The second graph is a graph of the coke leftover from the experiment. When the Coke was hot it made the highest geyser with an average of 220 cm in height. During the experiment, when the Mentos were dropped in, the coke would fizz and then make the geyser. When the geyser is in action, the fizz comes up in the air and then parts to fall back down.
200
Height of Geyser (cm)
180 160 140 120
100 80 60
40 20 0 Diet Coke
Coca-Cola
Coke Zero
Type of Coke Product
Figure 4: Height of Geyser 760
Coke Leftover (mL)
740 720 700 680
660 640 620 Diet Coke
Coca-Cola
Coke Zero
Type of Coke Product
Figure 5: Coke Leftover
In the first graph the average height of the geyser for the different coke products tested are shown. In the second graph, all of the liquid that was left in the bottle after the geyser was poured into a beaker and measured in milliliters. Coke Zero had the highest geyser with 181 cm in height and Coca-Cola had the smallest geyser with 83 cm. After the experiment was conducted, the liquid was poured into the beaker and the CocaCola bottle had the most liquid leftover because it made the smallest geyser.
120
Height of Geyser (cm)
100 80 60 40 20 0 Full Bottle (2 liters)
Half of a Bottle (1 liter) Half of a Liter (1/2 liter)
Amount of Coke
Figure 6: Height of Geyser
In the graph for the third experiment, it is shown that when the full bottle of coke was used, it made a higher geyser than the half bottle and ¼ of a bottle. When only ½ of a liter was used, it didn’t do anything. It didn’t make a geyser and it didn’t even fizz. The full bottle of coke went 96 cm in the air. The data is an inverse relationship because it goes down when amount of Coke used also goes down.
Figure 7: Diet Coke and Mentos Geyser
CONCLUSIONS The hypothesis that was created was incorrect. The Coke expanded when it was hot so it made a bigger geyser. When the Coke was hot, it had an average of 220 cm in height during the geyser when the Coke that was cold only went and average of 57.5 cm. It was the opposite for the amount of Coke leftover because it used the most coke when the geyser was done.
For the second experiment, Coke Zero had the highest geyser so it was realized that Coke Zero is the best type of Coke product for Mentos geysers. In the third experiment, the full bottle of Diet Coke made the biggest geyser and the ¼ of a bottle of coke made the smallest geyser so it was realized that the more Diet Coke that is used, the bigger the geyser will be. While the ¼ of a bottle of Diet Coke geyser was in action, the Coke didn’t do anything. It didn’t even fizz at all.
A way to improve this experiment next time would be to tape the meter sticks up so they are straight instead of holding them up after putting the Mentos in the Coke. Another experiment would be to use more than one type Mentos in the geyser at one time.
REFERENCES Challoner, Jack. The Visual Dictionary of Chemistry. New York: DK Publishing, 1996. Print.
Ganeri, Anita. Indoor Science. New York: Dillon Press, 1993. Print.
Spangler, Steve. Secret Science. Sandy: Silverleaf Press, 2007. Print.
VanCleaves's, Janice. Chemistry for every kid. Canada: John Wiley & sons inc., 1989. Print.
"Why Does Mentos Make Coca-Cola Go Rocketing out of the Bottle?" Questional Interviews, Blogs, Questions & Answers With Tech and Science Experts, Professionals, and Scientists. Web. 15 Feb. 2012.
