Soda and Mentos Geyser Experiment: Creating a Fizzy Explosion

The Soda and Mentos geyser experiment is a classic and exciting demonstration of the interaction between carbon dioxide gas and liquid. In this experiment, you’ll create a dramatic geyser by dropping Mentos candies into a bottle of soda. This experiment is both fun and educational, providing a hands-on way to explore gas release and nucleation.

Soda and Mentos Geyser Experiment

Materials Needed for this science experiment:

  1. Two-liter bottle of soda (diet soda works best due to lower sugar content)
  2. Mint Mentos candies (other flavors might work, but mint is recommended)
  3. Outdoor space (preferably grassy area)
  4. Safety goggles (recommended)
  5. Protective cover for the ground (optional, to contain the mess)


1. Choose an Outdoor Space: This experiment can get messy due to the rapid fizzing and spraying of soda. Perform it outdoors on a grassy area to avoid damaging surfaces or making a mess indoors.

2. Put on Safety Gear: Wearing safety goggles is recommended to protect your eyes from any splashes. Although the reaction is safe, it’s better to take precautions.

3. Open the Soda Bottle: Remove the cap from the two-liter bottle of soda. To prevent immediate fizzing, it’s a good idea to let the soda sit out for a little while to reach room temperature.

4. Prepare the Mentos: Open the package of Mentos candies. You can use a small piece of tape to create a tube-like structure by attaching multiple Mentos candies together. This will make it easier to drop them all at once into the bottle.

5. Position the Bottle: Place the opened bottle of soda on a flat and stable surface. Make sure it’s positioned in an upright manner.

6. Drop the Mentos: Hold the Mentos tube above the opening of the soda bottle and quickly drop them all in at once. Be prepared for a rapid and powerful reaction!

7. Step Back: Immediately step back to a safe distance to avoid getting splashed as the geyser shoots out from the bottle.

8. Observe the Geyser: Watch in amazement as a tall and fizzy geyser shoots up from the soda bottle. The reaction occurs due to the release of carbon dioxide gas from the Mentos candies, which forms bubbles and causes the soda to foam up and spray out.

9. Record Observations: Observe the height and duration of the geyser. You can compare results with different types of soda or different brands to see how they affect the reaction.

10. Discuss the Science: After the geyser has subsided, discuss the science behind the experiment. The rough surface of the Mentos candies provides nucleation sites for carbon dioxide gas bubbles to form rapidly, leading to the explosive reaction.

11. Safety and Clean-Up: Make sure to clean up the area after the experiment, as the sprayed soda can attract insects. Also, avoid consuming any soda or candies involved in the reaction.

The Soda and Mentos geyser experiment is a classic example of a simple reaction with fascinating results. It provides a hands-on experience of chemical reactions and gas release, making it an exciting and memorable experiment for both kids and adults.

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