Making a volcano out of a soda bottle is a classic science experiment that opens the door for lots of geological exploration, as well as a chance for the kids to make an explosive mess! It only requires two ingredients, a few minutes, and a place outdoors to do it.
Making a Diet Coke Volcano
The purpose of this experiment is to demonstrate how carbon dioxide gas in the Diet Coke can cause a volcanic eruption when mixed with Mentos. Carbon dioxide is a colorless and odorless gas. It is what gives the Diet Coke it’s fizz.
- Buy a two liter bottle of Diet Coke and a roll of Mentos.
- Take them outside to a flat space.
- Open the Diet Coke and place it on the flat surface where it will easily stay standing upright.
- Open the roll of Mentos the long way and then use tape to loosely hold it together. This will allow you to have a funnel-like tube to assist in getting the Mentos into the bottle.
- This explosion will be big! Therefore you have to quickly drop all Mentos into the two liter bottle and get back.
While this explosion does not mimic the actual process of a volcanic eruption, it does give you an idea of the type of force and flow of a volcanic eruption.
So what happened? When the Mentos candy is dropped into the Diet Coke, which is filled with carbon dioxide gas, the gelatin and gum arabic from the dissolving Mentos creates an energy that breaks the surface tension of the soda. When the Mentos hits the soda, bubbles immediately begin to form on their surface. When the candy hits the bottom of the bottle, the gas is released and pushes all the Diet Coke out of the bottle and into the air!