Why does my can of soda overflow when I first open it?

Question

I purchase a diet coke from the vending machine at work everyday. When I open the soda the liquid fills the top surface for a few seconds before returning to the inside of the can. Does anyone know the reason for this?

Answer 1

I don't know why it does it.. but if you have a can soda you can tap the top a few times and it won't do that... at least it works for me... a friend told me about it.

Answer 2

Yes, the carbonation in the pop gets shaken up while going through the machine.  So it foams over when you open it.  You can help this by tapping on the top a couple of times or flicking it with your forefinger.  That should help, it usually does when I do it.

Answer 3

Because when the soda hits the bottom it stirs up the carbonation( just as if you shook the can).

Let it rest for a few minutes then open it slowly.

Answer 4

Any thing carbonated in a sealed container builds pressure. Especially when aggravated. So when your can moves from its resting place to the bottom where you receive it the process begins. Pressure builds and then when you open it the pressure releases. If you set it down for a minute after you get it from the machine you won't have this problem.

Answer 5

cuz it has been shook. tap the tab before opening it

Answer 6

The diet coke has carbonated water(i.e SODA). The container is pressure packed and when it is opened for the first time,the carbondioxide in the soda will rush out to the atmosphere.so it Fizzes with bubbles when you open the can for the first time

Answer 7

the liquid fizzes out only when it is cold,this is due to vapor pressure. soda or any aerated drink is highly acidic.did you know,soda has a pH of 2.8 which is equal to your toilet cleaner.

Answer 8

When the can of soda gets shook up or handled roughly, the air bubbles in the carbonated water build up inside of the can increasing the pressure.  When you pop the tab all of the pressure and air is trying to escape all at once, taking the soda with it.  Thus the liquid fills to the top surface.  Once the pressure has escaped, the liquid goes back down.  Sometime A LOT of pressure builds up inside the can, so when you pop the tab it sprays all over you.  That's always funny to watch.

Answer 9

overflowin usin usually happens to carbonated drinks especially the canned products.care should be taken not to shake or disturb the can .u should tap it on top n open it slowly