Soda Geyser

Area of Science: Chemistry
Meant for at least Grade 7-9 (age 11-13).
This experiment is edible.
An adult should be present.

Creates a *spectacular* geyser out of a bottle of soda.


  1. An old soda bottle cap.
  2. 6 circular Mentos.
  3. A new unopened 2 liter bottle of soda(any kind).
  4. Dental floss.
  5. Tape.
  6. Nail.
  7. Hammer.
  8. Open space.
  9. Adult (for effect).
Anyone or anything in the path of the spray will get soaked. Have goggles and do not perform inside.

How to do the experiment:

  1. Make a hole in the center of the old bottle cap using hammer, nail, with help from an adult.
  2. Make a hole in the center of all 6 mentos.
  3. String the mentos together with floss.
  4. Tie a knot on one end of the floss so the mentos dont fall off.
  5. Put the other end through the hole in the bottle cap.
  6. Tape it down to the cap.
  7. Replace the cap on the new bottle with the cap holding the mentos.
  8. Quickly remove the tape and drop the mentos in the bottle and get away from the bottle. (For a higher geyser, shake bottle, and then drop in mentos.)
The mentos case the rapid release of CO2, dissolved in the soda, as CO2 gas. The released gas rapidly increases the pressure inside the bottle, forcing the liquid out through the small hole in the cap.

Useful References:
MadSci Answer: What is the chemical equation that occurs when mixing soda and mentos?

Further comments:

Experiment submitted on Tue Mar 21 15:22:41 2006 by MadSci Admin


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