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Simple water question

  1. Jul 15, 2004 #1
    Hi all,
    today someone asked me a very simple question:
    "If I have some soda water, and put it in the deep-freeze in an open vessel, so as to make ice, and take it out again later, and let the ice melt,
    will the water bubble as before? Or not?"

    Of course I said, "Try it!". But I'd like some theoretical background. Obviously, the water bubbles because of the H2CO3 dissolving into H2O + CO2. So the question is, what happens to the H2CO3 when the water starts to freeze. One should expect that the H2CO3 freezes earlier because the molecule is heavier, and thus is conserved. But you never know...

    Any help? Thx...
  2. jcsd
  3. Jul 15, 2004 #2
    You said in an "open vessel" so I'm assuming you're pouring it out from it's original container into something else.

    The CO2 I think would dissipate and you'd be left with frozen water. Water can hold so much CO2 at normal pressures and temperatures. When you reduce the pressure (ie. you open the bottle), AND you reduce the temperature of its surroundings, the solubility of the gas becomes VERY low...So all the gas should be gone!
  4. Jul 15, 2004 #3
    Solubility of gases increases with decreasing temperature. Heating water is a good way to start degassing. That's why you get clear ice cubes from freezing hot tap water.

    I have frozen Coke before and it is still fizzy after thawing (doesn't taste right though).
  5. Jul 16, 2004 #4
    Thanks. :smile:
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