6
$\begingroup$

When I place a straw in carbontated drink and blow (making bubbling noises), more gas bubbles rise to the surface. The gas bubbles which rise to the surface are from the carbon dioxide gas dissolved in the drink, I'm not talking about the air bubbles I made with the straw?

Why does this happen?

$\endgroup$
  • $\begingroup$ Can you be a little more specific about your "experimental" set up? Maybe while blowing your breath into the drink, you also stir it up a little? $\endgroup$ – Martin - マーチン May 13 '15 at 14:17
6
$\begingroup$

When you blow into a solution, your warm breath (~98.6°F) warms the solution up. As a solution warms up, less $\ce{CO2}$ is soluble. Therefore, blow into a solution, warm it up, less $\ce{CO2}$ is soluble, $\ce{CO2}$ escapes (bubbles out) from the warmer solution.

enter image description here

(image source)

$\endgroup$
  • 4
    $\begingroup$ Hmm I never considered this simple possibility. I thought the blown air was acting as a nucleation site for removal of the supersaturated $\ce{CO2}$ in solution. Bubbles are good at nucleating other bubbles, which is why opening shaken cans of soda is not a good idea! $\endgroup$ – Nicolau Saker Neto Apr 24 '15 at 1:56
  • 4
    $\begingroup$ I don't believe this answer is fully correct. I repeated the experiment, this time using one of those dust-off air blower things, which blow out COLD air, and I got the same effect. In fact the more intense the spray, the more bubbles. So there's something more here. $\endgroup$ – Joshua Benabou Apr 24 '15 at 1:58
  • 3
    $\begingroup$ I downvoted the answer because its incomplete. Increasing temperature of the solution can't be the only reason and when the temperature actually decreases it's not a reason at all. I think Nicolaw Saker Neto has the other half with bubbles nucleating other bubbles. $\endgroup$ – Joshua Benabou Apr 24 '15 at 2:52
  • 2
    $\begingroup$ @ron But blowing a few air bubbles into a glass of Coke doesn't increase its temperature by anything even close to 10°C. Heat conduction between a gas bubble and a liquid is very slow and the bubble exists in the liquid for, what, about a second? I'd be surprised if blowing bubbles had any significant effect on temperature. $\endgroup$ – David Richerby Apr 24 '15 at 9:00
  • 1
    $\begingroup$ @ron Nothing in the question talks about blowing a whole lungful of air through the drink. $\endgroup$ – David Richerby Apr 25 '15 at 15:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.