Mentos and Diet Coke Fountain

I saw this experiment investigated recently on MythBusters on the Discovery Channel. I'm always impressed with the scientific breakdown of these experiments and why they may or may not work. Adam Savage and Jamie Hyneman are the guys from the show who put urban myths, commonly held beliefs and tall tales to the test.

They featured this video during the show and it took me a while to find in a shareable form but here it is. Pretty amazing stuff, a scientific work of art.



According to Hyneman (he's the mustachioed MythBuster), it's a process called "nucleation," in which the particular chemistry of the Mentos candy interacts with the chemistry of the carbonated Diet Coke, causing the carbon dioxide gas, or CO2, to suddenly come out of suspension in the liquid and make a break for freedom.

You need the right Mentos though because they have different chemical make-ups and not all of them will work. You've got to have the minted kind. Apparently it's because they surface is more porous than the glazed non-mint kind and this allows the gases to escape through.

When the Mentos are dropped into the Diet Coke, a cascade reaction occurs when the Mentos dissolve and the CO2 in the liquid loses its attraction within the liquid because if the chemical reaction occurring. You also need to have diet soda because the sugar levels in regular soda slows the reaction process down.

Hyneman did try taking a big drink of soda and then popping a few mentos and he said "...the soda pretty much came out my nose and sprayed all over the place. Everyone laughed. I've got this big mustache -- it's kind of my trademark on the show -- and it was dripping all over off this mustache and made a big mess. Just drink the soda and enjoy it, and then eat the candy some other time.