Adding Mentos candy to Coke is the stuff of legend. Every kid has heard the rumors about the explosive combination that results, but how many have actually tried it? While science teachers have been performing this experiment for years, it was first popularized in September of 2005 thanks to a viral video from Steve Spangler Science. The several-foot-high geyser that shoots from the soda bottle is a fun and awe-inspiring hands-on activity that any scientist in the making can perform. Be forewarned though: You’ll probably want to perform this experiment outside.
Read on to learn more about the Mentos and Coke experiment, and fill out the form on this page to grab your free recording sheet for the experiment.
How does the Mentos and Coke experiment work?
In this experiment, you drop Mentos mints into a 2-liter bottle of Coke. Make sure your bottle of soda is on a flat surface in a location where it is OK to make a mess. You then load the Mentos into your paper roll or geyser tube. Once the Mentos are dropped into the soda, they sink to the bottom, which causes the gas to expand and pushes the soda out of the bottle. This creates an exploding geyser effect.
What does the Mentos and Coke experiment teach?
Although you can’t see it, dissolved carbon dioxide is the invisible substance that makes soda bubbly and fizzy. As long as the soda remains in the bottle, the gas is kept in place through the pressurized conditions. When you shake a bottle of soda, some of that gas is released and the bubbles stick to nucleation sites or tiny defects on the inside of the container. If you open the shaken bottle, the bubbles will rapidly rise and push the liquid up and out of the bottle.
Aside from shaking the soda, another way to help the carbon dioxide escape is to drop an object into the bottle. Mentos are the perfect objects, since each candy has many little pits on its surface that serve as nucleation sites. Once the Mentos are dropped into the soda, the bubbles stick to those sites and quickly rise to the surface. The weight of the Mentos drives them to the bottom of the bottle. Then, the gas that is released by the Mentos forces the soda to shoot out of the bottle in a powerful geyser.
Is there a Mentos and Coke video?
This video shows how to do the Mentos and Coke experiment using just a few simple ingredients and supplies.
Materials Needed
To do the Mentos and Coke experiment, you will need:
- A roll or box of mint-flavored Mentos
- 2-liter bottle of Coca-Cola (aka Coke)
- Sheet of paper to roll into a tube OR pre-made geyser tube
- Tape
Our free recording sheet is also helpful—fill out the form on this page to get it.
Mentos and Coke Experiment Steps
1. Make a paper tube by taking a piece of paper and wrapping it around a roll of Mentos, then taping it in place. Pull the Mentos out. Alternatively, you can use a premade geyser tube available from Amazon or other retailers.
2. If using a geyser tube, load the Mentos. If using a homemade paper roll, drop the Mentos into the roll while holding the bottom closed with your finger.
3. Placing a 2-liter bottle of Coke on a flat surface, remove the cap, and drop the Mentos into the open Coke bottle.
4. Run!
Grab our free Mentos and Coke experiment worksheet!
Fill out the form on this page to get your worksheet. The worksheet asks kids to guess the correct order of the steps in the experiment. Next, kids must make a prediction about what they think will happen. They can use the provided spaces to draw what happens before and after they add the Mentos. Did their predictions come true?
Additional Reflection Questions
- What happened when we added the Mentos to the Coke?
- What difference do you think the temperature of the Coke makes?
- What do you think would happen if we used different-flavored Mentos, like fruit?
- What do you think would happen if we used a different soda other than Coke?
- What do you think would happen if you use Diet Coke?
Can the Mentos and Coke experiment be used for a science fair?
Yes! If you want to do the Mentos and Coke experiment for a science fair, we recommend switching up some of the variables. For example: Does the temperature of the Coke matter? Does the brand of soda matter? Will generic soda produce the same results as the brand-name soda? What happens if you use fruit-flavored Mentos? What happens if you use Diet Coke instead of regular? Form a hypothesis about how changing the variables will impact the experiment. Good luck!
