Exploding Soda
| Chemistry: | Nucleation Points, Effervescence |
| Grade Range: | Elementary School, Middle School, High School |
| Format: | Stage |
This is the classic diet Coke and Mentos demonstration, which everyone knows and loves! All grades will enjoy seeing this demonstration in action, but be sure to put a tarp down if you perform this indoors. This demonstration is definitely messy!
Materials
- Diet Coke
- Mentos
- Geyser Tube
- Tarp (if indoors)
Safety Precautions
Please read the General Safety Precautions section of the Demonstration Safety page before performing this demonstration.
This demonstration requires: safety glasses
Demonstration
- Set up the geyser tube: put 4-6 Mentos into the tube, and connect it to the 2L bottle.
- Ask the audience if they have ever done this type of demonstration before. Likely a number of them have; ask them what they expect to happen, and if they have any theories on why it happens.
- Ask for a countdown. At the end of it, pull the string to drop the Mentos. The soda will erupt out of the tube!
Why This Works
Mentos are pretty smooth. However, they have a lot of tiny bumps and holes across their surface. When the Mentos are dropped into the diet Coke, the bumps and holes become Nucleation Points for the CO2, or spots for the bubbles to form. When bubbles start to form on the Mentos, they cause a chain reaction, with more bubbles forming on the bubbles already formed. This process, called Effervescence, results in a lot of rapidly forming foam, which erupts out of the bottle!
Additional Information
- This demonstration is common, and there isn't much information to expand on. If students are interested in learning more, you can expand on where they have seen effervescence, such as a pot of water boiling over!
- This demonstration pairs well with the Bouncing Raisins demonstration.