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I know this may actually be a chemistry question, but I don't know where else to ask.

When I have a soda plastic bottle, I turn it upside down so the soda fills the empty space, and bubbles start growing on the walls of the plastic.

So, why does this happen? I can think of something like a film forming around the empty space, and it reacts with the liquid, if so, what is it? why does it react that way?

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  • $\begingroup$ Hi Goodwine, and welcome to Physics Stack Exchange! This doesn't actually involve a chemical reaction, it's more about transitions between states of matter, so it should be fine here I think. $\endgroup$ – David Z Jan 24 '12 at 22:06
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When you turn the bottle upside down, the bulk gas moves through the fluid, and is partially redissolved, and at the same time there is a turbulent flow, which acts to seed little irregularities in the fluid, where the slightly supercritically dissolved CO2 outgasses. This distributes the same volume of gas over different places in the container, and some of it sticks to the side. There is nothing unusual going on--- if you tap the side of the bottle to dislodge the bubbles, and wait for the littlest bubbles to float to the top, the liquid returns to equilibrium.

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  • $\begingroup$ And I suppose that it sticks there thanks to the remains left from the dry soda, so when the liquid soda goes over it, the CO2 begins to come out again $\endgroup$ – Goodwine Jan 25 '12 at 15:49
  • $\begingroup$ @Goodwine: It could be, but I think it is more plausible that there are seeds for bubble nucleation in the irregularities in the plastic, leading the bubbles to form directly on the surface. This can be easily resolved by making a movie of the process. $\endgroup$ – Ron Maimon Jan 27 '12 at 0:58

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