Why does soda fizz?

[Wing Nut]

I was wondering (after a nasty little incident), why does soda fizz up when I shake it?  I know it's that carbonation, but what causes it to go from calm to all over my shirt when I'm not careful?  :D

[Saitek]

Its all to do with pressure. The gas is under pressure before you even shake it. In the factory it is forced into the bottle with the liquid at the same time.
When the bottle gets shaken the under pressure carbon dioxide particles gain even more energy which builds up. When the bottle is about to be opened the pressure is very high and the opening is very narrow. The opening of the lid is like popping a balloon. The sudden drop of pressure causes a violent burst of liquid to come shooting out. This pressure shoots it out and over you.

Well thats my interpretation and understanding. I expect someone else can give a better answer.

Ben

[Stormtropper]

When you shake it, you mix air into the liquid soda, therefore making free O2s avalible to the Cs in the soda. Then the stupid chemical reaction and makes your soda all flat and stuff. And after the reaction, you got more CO2s and thats a gas, so it takes up more room and with the carbon dioxides taking up the bottle, the soda has no where to go, and the only way out will be through the hole which you will take the cap off of.

Hope that explained

Jeff

P.S. Here is something fun that you can do with a soda, get a can (12 oz I think) of coke, and put it on the ground and kick it as hard as you can. If you kick it hard enough, it will go into the air and then explode................really fun

P.P.S. If you did what I just recommended above, then get ready to wash your house

[Hagar]

That sounds a pretty good explanation to me Ben.

I've never thought about this before or wondered why it happens. I learned from a very young age that if you shake the bottle or can before opening it everyone within range is liable to get soaked. Not a good idea - unless it's champagne of course.

[flyboy 28]

Sounds like somthing Poly should know...

[Scorpiоn]

Another thing.  To keep a 2 liter gassy, turn it upside down.  So long as the air isn't touching the cap.

[Fozzer]

[quote]I was wondering (after a nasty little incident), why does soda fizz up when I shake it?