Supplies
2-liter of Diet Coke
6 mentos
paper rolled into tube (big enough for Mentos)
index card or card stock square
Concept: Diet Coke and mentos have an explosive reaction when they are combined. The Diet Coke starts to make holes or pit the candy rapidly. This causes a gaseous reaction producing a fountain, rather than dissolving the candy.
Procedure: Place 2-liter of Diet Coke on a flat surface (outside). Open the 2-liter and place the index card or card stock over the top. Place the rolled paper tube above the index card/card stock and drop in 6 mentos. Slowly pull out the index card/card stock square and allow the mentos to drop into the liter.
Extension: Try using various 2-liters of diet soda and non diet soda and compare results. Use different kinds of mentos (mint vs fruit) to document comparasion. Add more or less mentos and record how the results vary. Also, vary how quickly or slowly the mentos are dropped into the soda.
Application to the Real World: The show MythBuster's feautured an episode on this experiment concluding the caffeine, potassium benzoate, aspartame, and CO2 gas in the Diet Coke combined with the gelatin and gum arabic in the Mentos create the eruptive fountain. MythBusters also theorized the physical structure of the Mentos as a vital component in the eruptive effect due to nucleation.
