A freshly opened soda is placed in a vaccuum pump. Why does it appear to boil immediately?

When I open a bottle of my home brewed lemonade I have to open it VERY slowly. It takes more than a minute for the lemonade to stop "boiling". If I take the lid off quickly then all my lemonade is on the ceiling and none is left in the bottle. Oh bother.

Now back to the substance. What is "boiling". That happens when the partial pressure of water vapour ( steam) is greater than atmospheric. So any tiny bubble grows in size pushing the water which pushes the air out of the way.

It can only do this if the pressure is greater than that of the air.

Now in the soft drink we have carbonic acid in solution in water.

The concentration is sufficiently high that it can only be maintained by a pressure above atmospheric.

Once the pressure is released then small bubbles grow in size pushing the soft drink and the air out of the way.

ie it is identical physically to boiling even though caused by a different property.

Now after a while the concentration of carbonic acid reduces. The partial pressure is not sufficient to force the air out of the way.

This is similar to water evaporating at lower temperatures.

The bubbles do not expand rapidly but merely rise to the surface.

Now one final thing. It is temperature dependent.

At a higher temperature ( room temperature) this is all common. But at a lower temperature the partial pressure of CO2 is less.

This leads us to the possible global warming problem.

If the temperature rises then CO2 in the oceans can be released into the atmosphere. Adding to the CO2 adding the warming.

If this happens then we do have a problem.

Lower pressure, and the release of carbonation bubbles (not boiling, but it may look like that).

That would be very strange. When I tried it, the soda didn't boil until the pump reduced the air pressure more than a little bit.

The dissolved gases in the soda would be released all at once due to the pressure difference.