Soda geyser

Objective

To make a geyser using diet soda and Mentos mints

Difficulty:

Time: approx 10 minutes

Adult supervision: no

Dangers: spraying soda

Materials

Bottle of diet soda (unopened)

Mentos mints (5 mints for a 2 L soda bottle)

Make sure you do this activity outside!!

Diet soda geyser from Wikipedia

Instructions

Place the bottle outside in a place where getting soda spray won't damage anything.
Undo the lid of the soda bottle.
Drop the Mentos mints into the bottle and watch the geyser!

The Science

The sugar in the Mentos catalyzes (makes the reaction go faster) the release of carbon dioxide from the soda. The geyser seems to be better with Diet Coke (and possibly other diet sodas) due to the presence of aspartame (an artificial sweetener), potassium benzoate (a food preservative) and other flavourings.

Further investigation

Which soda produces the best geyser?
Will other brands of mints produce the same geyser?