How does the volume of gas in a pop bottle change on opening the
bottle? - When you open a bottle of soda does the air go in or
out of the bottle and what is the volume of the air released or
allowed in? Stretching a balloon over the top of the bottle and
popping off the cap under the balloon will reveal that gas
leaves the bottle; the balloon most definitely expands. So gas
will rush out of the bottle, but this gas is not air; it's
mostly carbon dioxide saturated with water vapor, but other
gases are present as well. Computing the final volume of the gas
after the top is removed requires additional information. The
gas is released in two stages: - The gas originally trapped in
the head space has higher than atmospheric pressure and will
expand very quickly out of the bottle. - Gases dissolved in the
soda will be released as well, but more slowly. Notice that
these gases stay in the soda until the bottle is uncapped. You
don't see bubbles until the cap is off. This is because the
solubility of gas in the soda