Saturday, 7 February 2009

Diet Coke and Mentos eruption

Group 7 - Gabriela M, Liana R, Andrada S, Madalina S - Colegiul Naţional "Mihai Eminescu" Satu Mare, România

The reaction was the subject of an August 9, 2006 episode of MythBusters, a popular television program on the Discovery Channel. They concluded that the caffeine, potassium benzoate, aspartame, and CO2 gas contained in the Diet Coke and the gelatin and gum arabic ingredients of the Mentos all contribute to the jet effect. In addition, the MythBusters theorized that the physical structure of the Mentos is the most significant cause of the eruption due to nucleation.

When flavored Mentos with a smooth waxy coating were tested in carbonated water, no reaction occurred, whereas standard Mentos added to carbonated water formed a small eruption, by their claim, affirming the nucleation-site theory. According to the Mythbusters, the surface of the mint Mentos is littered with many small holes, allowing CO2 bubbles to form very rapidly and in great quantity, in turn causing the jet of foam. This was further supported when rock salt was used as an effective substitute for Mentos.

O'Hare, Kate, "The 'MythBusters' Take on the Mentos/Diet Coke Craze", retrieved on 21 January 2007

A paper by Tonya Coffey, a physicist at Appalachian State University in Boone, North Carolina goes into detail on the reasons and physics behind the reaction.

Steve Spangler, who first put the Mentos Geyser in the public eye, has several videos and detailed experiments about it on his website. The Geyser Tube is a device invented for use in creating the reaction.
Diet Coke & Mentos_GabrielaM


Nacho said...

I like mentos, but even more diet coke. It´s cool

Anonymous said...

too classic, you could do it more original putting more bottles like a fountain or something else

Anonymous said...

too classic, you could make it more original putting more bottles like a fountain or something else

Mercedes said...

It's quite interesting, but is diet coke the only one which can be used? Isn’t normal coke suitable for this experiment?