|MadSci Network: Chemistry|
First, for those who are curious about what this reaction looks like, visit Diet Coke and Mentos to see for yourself. Please note that the correct "control" for this experiment would have been a 2L bottle of tonic water, with a clean, dry delivery tube and a new packet of Mentos.
Second, this reaction is not really chemical, although it can be described by the equation: CO2(l) --> CO2(g)
More details about what is happening can be found here:
How do mints in diet cola make it fizz? and
nucleated sites/ wintergreen lifesavers.
P.S. A fun variation on this experiment is to punch a hole in the bottle cap before you take it off the 2L bottle. Very quickly, drop a single mint into the room-temperature soda, replace the cap and RUN! You should see a 6 to 8 foot geyser shoot out of the top.
And make sure to avoid a very sticky situation by working outside with these materials!
Try the links in the MadSci Library for more information on Chemistry.