BrainStorms: Science with Scottlin – Mentos and Coke

Science With Scottlin

JACKSON, Miss. (WJTV) – This week was a BLAST – literally. I’m sure you have seen the Mentos and Coke explosion before, but have you ever done it? Well, we haven’t and we’re are so excited to and also excited to learn why this happens!

GRAB YOUR INGREDIENTS: a 2-liter of diet coke, a roll of Mentos, a sheet of paper, and tape.

NOTE: Since this will get messy, I’m not sure our bosses or your parents will like us doing this inside. So, we are going to head out back!

STEP 1: Roll the paper into a tube around the pack of Mentos, tape it into place and pull it off of the roll of mints.

STEP 2: Use your finger to block one end of the tube and fill it with the Mentos.

STEP 3: Hold the tube over the bottle and countdown to drop the mints in.

NOTE: This happens pretty quickly, so be ready to step back.  

Science behind this experiment: Soda is a carbonated beverage meaning it has a lot of dissolved gas that wants to come out of solution, but they need a surface to form on. So, what is really going on in this reaction between the candy and the soda? It all boils down to what is called nucleation. The reason we choose Mentos is because they are covered with microscopic pits. Each little corner has a nucleation site where carbon dioxide bubbles from the soda can form and escape.

When you look at a Mento, you may think that it has a smooth surface, but microscopically it’s kind of like the surface of the moon and that is the key to this experiment. Every crater provides that nucleation site and allows a carbon dioxide molecule to change to gas forming bubbles. When we drop the Mentos in, millions of CO2 bubbles form very quickly and since the candy sinks, gas is released quickly at the bottom of the soda, so we get the fountain like explosion.

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Trending Stories