Homely Scientist

The perfect experiment for kids: easy, cheap, and messy!

Found this experiment this morning on Aetiology … take about a dozen Mentos (yeah the fresh maker) dump all at once into a 2 litre bottle of pop (diet or regular) and you get … a soda geyser!

What could be cooler!

The Disgruntled Chemist, in true science style, did a nice experiment testing pop in cans or bottles and various kinds of mints. Bascially, as expected, Mentos and 2 litre bottles win.

Why does this work? Is it some mystical reaction between Mentos and pop? Will you explode if you eat Mentos and chug a soda? No. Here’s the deal (both Disgruntled Chemist and Steve Spangler explain the reasons why very well), first carbon dioxide (CO2) is dissovled in the soda making it fizzy. Now, as you know by opening a pop bottle, CO2 comes out of solution (that is coming out of the pop) pretty easily (hence bubbles and foam). Mentos accelerate this process tremendously. The rough surface of the candies and their weight (so they sink quickly) give the CO2 something to jump from the solution to the air … and all at once in fact. And you get a soda geyser! Steve Spangler says he got one to go 16 feet in the air!

If you haven’t guessed, this is an outside experiment. To say this is messy is to say ice cream is a nice thing to have on a hot summer day. Understatement to say the least.

Hmm, I think the store still had some 1/2 price expired pop in the back last night … hmm. .