Does agitation make gases dissolve faster?

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Discussion Overview

The discussion revolves around the effects of agitation on the dissolution of gases in liquids, specifically focusing on carbon dioxide in soda. Participants explore the dynamics of gas solubility under agitation and the implications of pressure changes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the assertion that agitation increases the dissolution rate of gases, citing practical observations with soda.
  • Another participant suggests that agitation may create zones of varying pressure, which could influence the behavior of gas bubbles and surface tension.
  • A third participant explains that the CO2 in soda is maintained in solution by pressure, and that shaking the can releases this pressure, causing CO2 to escape rather than dissolve further.
  • It is noted that while agitation can enhance gas dissolution, it also accelerates the release of gases from supersaturated solutions, as seen when opening a can of soda.
  • A later reply indicates that shaking a degassed liquid could facilitate the dissolution of atmospheric CO2 until it reaches its solubility limit.

Areas of Agreement / Disagreement

Participants express differing views on whether agitation definitively increases the rate of gas dissolution, with some arguing it may lead to the opposite effect in certain conditions. The discussion remains unresolved regarding the overall impact of agitation on gas solubility.

Contextual Notes

Participants reference the role of pressure and supersaturation in gas behavior, but the discussion lacks consensus on the mechanisms at play and the conditions under which agitation affects gas dissolution.

ejnovek
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Why is CO2 released when soda is shaked, and dissolves again when the soda is stable?

My teacher in class today said that soluble gases will dissolve faster in the presence of agitation. In practice (e.g. shaking a bottle of soda), this seems to not be the case. Please explain

Thank You,

EJ
 
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Not really sure ... but in could be that zones of different pressure are created in agitation. The ones with lower than "calm" pressure will ease the opposition of surface tension by bubbles. And the ones with higher should see no effect.

I assume this is what happens when you hit a beer bottle from top towards the bottom than creates the well known beer fountain. While dropping a bottle on the table does not produce a similar effect at least in intensity.
 
The CO2 in a can of soda is kept in solution by pressure. When you open the can, this pressure is released and some of the CO2 comes out of solution and forms bubbles.

http://en.wikipedia.org/wiki/Carbonation

http://www.livescience.com/32492-why-does-soda-fizz.html

Adding energy to the soda by shaking the can or tapping on the side will cause some of the CO2 to come out of solution. If the top is opened simultaneously when a lot of the CO2 comes out of solution, then you'll get a soda fountain.
 
Agitation can make gasses dissolve in liquids faster, but this also means that it speeds up the reverse process: gasses coming out of supersaturated solutions. As SteamKing mentioned, opening a can of soda gives a supersaturated solution of carbon dioxide. Because carbon dioxide is above its solutility limit, it will come out of solution, and shaking helps this process occur more quickly. If you were opening a can of liquid which had been de-gased (and had no dissolved carbon dioxide), shaking this solution would help atmospheric carbon dioxide dissolve in the liquid until it reached its solubility limit.
 
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