Funny, about two nights ago I happened to stumble across a link to what looked like video from a different TV station's news show in which the demonstrator used Wintergreen Life Savers to do the same thing. The difference was that he didn't say that gum arabic was the cause; according to him, it is "tiny imperfections" in the surface of the Life Savers that the bubbles form around. I'm not saying this is Gospel, but that's what the guy said (and demonstrated).

He also showed how you can open up a shaken soda can if you first tap the sides of the can once or twice. Same principle: the bubbles form around imperfections on the sides of the can, supposedly. Let the flame war begin!

You can make soda pop fizz by dropping many things into it. Try a couple of sugar cubes sometime. I'm not convinced that gum arabic (not "arabic gum") is the culprit.

As for tapping on the top, it also works if you tap on your own forehead. Try it and see.

But George, I don't think I want to open my own head.

The claim about gum arabic is strange, because some soft drinks also contain gum arabic or similar gums and resins.
I kid you not. Try reading all the ingredients lists on the cans of pop in the store sometime.

Okay.. so... I got suckered into this.

600ml bottle of Diet Pepsi + 1 Mentos = no more 600ml's of Diet Pepsi.

It was interesting to see, I did it in a mall parking lot, at night, and nobody really had any idea what I was doing.

I want to do it with a bigger bottle...

God I need a life.

Open a can of soda, and heat it to body temperature, then see how much carbonation is left.

Now, a carbonated lake, that is dangerous...

You know what? A "carbonated lake" would make a pretty good urban legend. Let's spread it!

Have some balls for god's sakes Andrew...do it in an airport terminal.

Actually, the 'tapping the can' thing is only signifigant on *old* cans of soda. Modern cans are coated on the insides. A shaken can will de-fizz *by itself* in about fifteen seconds, no matter what you do to it.

I can imagine buying a lot of cheap 'store brand' sodas and having Mentos-Cannon fights...

For real fun, try this *indoors*, with club soda. Since it doesn't stain or get sticky... Hmm.. thoughts..

http://www.stevespanglerscience.com/experiment/00000109

very similar, yet very cool.

I suspect the only reason it "shoots" out is because of the shape of the bottle. I think if that was just in a very big container, it would just fizz a whole lot.

I can't wait to do this. I should make a super-bottle that's huge and pour a ton of Sprite or some equally fizzy drink into it and use like 10 packs of mentos.

this is the most awsome thing ever.
i cant wiat to do this at school.

wait
wiat

its all the same

Cool video, but I'd say the explanation is false, although not a deliberate lie. Carbon dioxide is dissolved in the cola and not 'held in' by surface tension, which, IIRC, is the effect of weak hydrogen bonding. No hydrogen in carbon dioxide, so surface tension doesn't affect it. The 'imperfections in the surface' thing sounds equally dubious; I think there's a tendency of guys to just make up a scientific explanation that sounds right to them, and believe that. I know I do it.

My feeling is that the gum arabic might be a bit of a red herring.

It is not a chemical reaction - I had thought it was an acid/alkali reaction going on (like when you mix bicarbonate of soda and vinegar) but the ingredients of both Mentos and Soda seem quite similar.

Fizzy drinks contain carbon dioxide that was dissolved under higher-than-normal atmospheric pressure. So when you open a soda pop, you release the pressure, and the "excess" gas forms bubbles within the liquid.

If you provide any surface area at all for a fizzy drink to lie against, bubbles of carbon dioxide gas start to form on the solid surface - as the bubbles get large enough, they float to the liquid surface and pop - you can see that if you pour some into a clear glass. More solid surface area = more places for the bubbles to form.

Adding anything to a fizzy drink enables more bubbles to form and more bubbles to escape. Try stirring soad with a spoon - it gets less fizzy. Or dropping in a couple of raisins or grape seeds. So, I'm guessing that the Mentos (and I've never come in contact with them, so don't know what they look like) provide lots of surface area very quickly - maybe they break apart very quickly to form a high surface area?

What happens with dropping marbles in? Or pieces of cork? What's special about the Mentos?

The ammount of carbon dioxide that will dissolve in water increases in proportion to the atmosperic pressure. If the pressure drops, the CO2 will come out of solution and form bubbles around nucleation sites.
As the stomach is usualy sealed, any increase in nucleation sites (adding mentos) will initialy cause an increase in nucleation. This will cause a bubble of CO2 to form in the stomach, increasing the pressure in the stomach. If the stomach does not expand, the bubble will grow until the pressure matches the amount of CO2 that will dissolve, at which point no more bubbles will form.
Of course, the stomach is both capable of expanding, and equiped with a pressure release mechanism, so this is perfectly safe.

To see the effect of nucleation sites, pour vegetable oil into a tumbler, and swirl until an even coating of oil is on the inside of the tumbler. If you pour a carbonated drink into the tumbler, no bubbles will form, as there are no nucleation sites. Adding a pinch of granulated sugar will result in an explosive fizzing.

Another example of this effect is the ol' champagne/punch trick. In that one, you prank a bowl of punch (made with a carbonated beverage) or some champagne by throwing in a lot of finely granulated sugar. And what do you get? Lots of fizzing and fun!

i think that is really cool with the whole soda thing when i was 13 i was eatin so mentoes and i took a drink of my pepsi and it sprayed out of my noes it hurt so bad. My kids have done it also but they used the flavored kind of mentos

Er...what are Mentos?

They are the "Fresh Maker"

so.......