A Diet Coke and Mentos Eruption (alternately Diet Coke and Mentos geyser or Mentos eruption) is a reaction between the carbonated beverage Diet Coke and Mentos mints that causes the beverage to spray out of its container. The gas released by the candies pushes all of the liquid up and out of the bottle for a huge explosion. Lee Marek and “Marek’s Kid Scientists” were the first to demonstrate the experiment on television in 1999. Steve Spangler’s televised demonstration of the eruption in 2005 went viral on YouTube, launching a chain of several other Diet Coke and Mentos experiment viral videos.
Side note: A 2006 episode of the television show MythBusters concluded that the caffeine, potassium benzoate, aspartame, and CO2 gas contained in the Diet Coke, in combination with the gelatin and gum arabic ingredients of the Mentos, all contribute to the jet effect.
Coke and Mentos