Mentos and Coke: How To Build A Soda Mentos Rocket

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If you’re wondering how to build a soda mentos rocket and have a fun STEM project of your very own, this is the place for you!

One of our very favorite exploding STEM activities has been this mentos and coke experiment. It’s a great example of a STEM activity that incorporates physics and math in a fun and engaging way.

Enjoy this activity as part of your Memorial Day or Independence Day celebrations or as part of your homeschool lessons during the school year.

All About The Soda Mentos Bottle Rocket

If you’re in the mood for an awesome STEM activity that ends with a BANG, you might consider building a soda and mentos rocket.  

Diet coke and mentos eruptions experiments are a very popular STEM activity for families with younger kids, but if you really want to up your mentos and diet coke game, especially if you’re working with older kids, a soda bottle rocket is the only way to go.

Check out this fun video of our soda and mentos rocket that we made the other day.  We had a lot of fun with this project!

This kind of activity would be the perfect way to celebrate Independence Day, Memorial Day, or New Year’s at home with friends and family.  

What’s more, you don’t have to wait for any particular holiday to make your own soda bottle rocket.  

Turn your bottle of diet coke into a projectile any time of year with your very own at-home physical reaction adventure.

Learning About Chemical and Physical Reactions 

STEAM and STEM activities for younger kids are easy to come by and the learning opportunities, though fun and exciting for youngsters, are usually fairly simple.  

While young kids will enjoy and benefit from this bottle rocket activity, this activity is geared more towards older kids.

Why?  Because the actual building of the rocket takes some higher-level building and assembly skills as well as problem-solving skills.  

However, the lessons on physical reactions and chemical reactions are universal no matter your age.  

If you’re working with a large family or kids of multiple ages, put the older kids to work on building and assembly while the younger kids enjoy a fun and practical lesson on physical and chemical reactions.

So what is there to be learned from a mentos and diet coke experiment?  

Chemical Reactions

First, there is a difference between a chemical reaction and a physical reaction. In a chemical reaction, different ingredients combine and then change one or the other (or both!) into a totally different element.  

The combination of these ingredients causes a chemical change or reaction.  

A simple example of a chemical reaction would be the combination of baking soda and vinegar.  When baking soda and vinegar combine, the bubbly reaction you witness is purely chemical.

When you drop mentos candies into a bottle of diet coke, you are not viewing a chemical reaction but a physical reaction.  

Physical Reactions

In a physical reaction, all of the components of the reaction are already there in the original ingredients, and what you are viewing is merely a rearranging of these components.  

Take the diet soda and mentos candies for example. A carbonated beverage is packed full of dissolved carbon dioxide gas, which forms bonds with water.  

When you open a bottle of soda, you release the pressure and some of the gas escapes.  

The same thing happens when you pour soda into a glass. However, most of the carbon dioxide gas stays bonded to the water molecules in the soda and does not get released until 

A: you let the soda go ‘flat’ or 

B: you drink the soda and then experience a higher frequency in burping.

Or in this case, there is a C: when you use another material to help break up the carbon dioxide’s bonds with the water.  

Why Does Coke and Mentos Explode?

So why do mentos and coke react? Well, although a mentos candy may look smooth, when you zoom in (such as with a microscope) you will see that the candies are not smooth at all!  Rather, they are very bumpy and almost canyon-like.  

When you drop a handful of mentos candies into a bottle of diet soda, you are breaking the carbon dioxide and water bonds in a very speedy way, thus resulting in a quick and explosive release of carbon dioxide gas.

And when you channel this release just right, you can create your very own projectile in the form of a soda and mentos bottle rocket.  

The image below gives you an idea of what your rocket launcher should look like. Ignore the soda in the top bottle. This image was taken of a failed attempt. Our seal wasn’t tight enough so instead of exploding, we just made a mess. Future attempts worked better. Make sure your seal is tight!

If you prefer to learn from video format, you can watch the videos below for more visual and auditory instructions on building your DIY mentos rocket.

What Happens If You Eat Mentos and Coke?

While consuming Mentos and Coke together may seem dangerous due to the results of our experiment, it’s important to note that the reaction between the two substances is unlikely to occur in the human stomach.

The MythBusters television show conducted an experiment to test the idea that the reaction between Mentos and Coke can occur in the stomach. They mixed Coke and stomach acid in a glass, then added Mentos to see if the same reaction would occur as when the two substances are mixed outside the body. They found that the reaction did not occur in the glass.

You can watch that episode here:

However, it’s still not a good idea to consume large amounts of Mentos and Coke. Both Mentos and Coke contain high amounts of sugar and other additives, which can lead to health issues such as obesity, diabetes, and dental problems when consumed in excess.

In addition, consuming large amounts of Mentos and Coke can lead to discomfort, bloating, and even abdominal pain due to the buildup of gas and pressure within the stomach. It’s important to remember that while the Mentos and Coke reaction can be a fun and exciting science experiment, it’s not safe to consume large amounts of either substance.

Encourage children to enjoy the reaction as a demonstration and not as a snack. Moderation, people!

Videos to Learn How to Build a Mentos and Coke Rocket  

This first video shows the components needed to build the soda bottle rocket launcher.

The second video quickly walks you through how to put the components together to build your very own DIY mentos rocket.

Don’t feel badly if you have to make any attempts before you have a working model. We followed some pretty clear instructions and we still had several failed experiments before it finally worked. That’s part of the STEM fun!

We had a lot of fun with our soda bottle rocket, and I hope you do too! This is a great STEM activity for teens that the whole family will love.

Free Printable Exploding STEM Project

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