Transform an ordinary day into an extraordinary one by combining Diet Coke and Mentos to create a spectacular soda fountain. Kids love watching (and doing) this fun, easy chemical reaction that combines two delicious ingredients to create a geyser of carbon dioxide bubbles.
Hint: This is definitely an outdoor experiment — it can get messy. Eye protection is recommended. Pick up some extra Mentos and Diet Coke, since your kids will want to do it again and again.
What You'll Need
- a two liter bottle of Diet Coke
- 2 rolls of Mentos mints
- 1 piece of 8x10 inch paper, like construction paper
How to Create the Geyser
Step 1: Remove the lid from the Diet Coke and set it the bottle of soda on a flat surface.
Step 2: Roll the paper into a tube around a pack of Mentos mints, tape it into place and pull it off of the roll of mints.
Step 3: Hold your finger over one end of the paper tube and have your child fill it up with Mentos mints. (It will probably hold a pack and a half of mints.) Check that the paper is unbent, so that the mints will easily fall from the end of the tube when you remove your finger.
Step 4: Hold the tube of mints over the mouth of the bottle. (Older kids can do it themselves.) Do a count down and when you shout “one,” quickly dump the mints into the bottle and stand back.
The Science Behind the Fun
Scientists aren’t sure exactly why the Mentos cause such an explosive reaction, but they think that the sweetener and other chemicals in the Mentos react with the Diet Coke to cause lots of carbon dioxide bubbles to form on the surface of the mints very quickly. This causes pressure to build in the bottle and send a spectacular jet of bubbles shooting into the air.
© Quarry Books, 2016/Outdoor Science Lab for Kids
Featured Photos Credit: © Quarry Books