science fair research: why does coke fizz when you put a mento in it? HELP!!!?

Question

i need to know the cause 4 my project.

Answer 1

i saw it on mythbusters. They said a mento casued coke to fizz due to carbon. The mento has small holes on the surface, allowing bubbles to come out while in the coke.

These chemists are saying that the primary cause is physical, not chemical. Their explanation: nucleation sites. If you have a liquid that is supersaturated with gas (like soda, which is pumped full of carbon dioxide), a nucleation site is a place where the gas is able to form bubbles. Nucleation sites can be scratches on a surface or specks of dust – anywhere that you have a high surface area in a very small volume. That's where bubbles can form.

Mentos seem to be loaded with nucleation sites. In other words, there are so many microscopic nooks and crannies on the surface of a Mento that an incredible number of bubbles will form when you drop it in a bottle of soda. Since the Mentos are also heavy enough to sink, they react with the soda all the way to the bottom. The escaping bubbles quickly turn into a raging foam, and the pressure builds dramatically. Before you know it, you've got a big geyser happening.

Your Welcome and Good Luck.

Answer 2

For starters, do your own experimenting for your science fair, can't you think on your own? Now to help you out..
There was an entire MythBusters episode that explored this. Look it up online, if you can.

It has something to do with the caffiene and a couple other ingredients in diet Coke, and the dimpled surface area of the Mentos reacting.