a scientific discussion about cold water.

Discussion in 'General Off-Topic Chat' started by test84, Mar 28, 2008.

Mar 28, 2008
  1. test84
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    Member test84 GBAtemp's last ninja 2.

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    its interesting,
    Whenever I pour water into a plastic bottle and put it in the freezer and take it out just when its so cold but its not frozen yet, just when you bring it out of freezer, it will freeze but it wasnst frozen when you brought it out of the freezer but it just got froze when you brought to a hotter place, the room.

    why is that?
     
  2. DrediKnight

    Newcomer DrediKnight Member

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  3. fischju

    Member fischju Rehabilitated Jaywalker

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    It is because sitting in the freezer, it isn't moving. (To make it very short)
     
  4. test84
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    Member test84 GBAtemp's last ninja 2.

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  5. test84
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    Member test84 GBAtemp's last ninja 2.

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    I skimmed through those articles but as I investigated the freeze, I realized its set to -5 °C but for supercooling it should be around -42°C.

    I'll investigate more! (hint: Private Investigation by Dire Straits)
     
  6. Destructobot

    Member Destructobot Crave the Hammer

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    What will freeze? The water touching the inside of the bottle? (i.e. just a thin skin of ice) The water that condenses on the outside of the bottle? The whole thing?
     
  7. test84
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    Member test84 GBAtemp's last ninja 2.

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    yes, just when you bring the bottle out, there creates some thin ice inside it.

    it seems that in the freezer, there is something going on with the water (or the plastic bottle) that doesnt let the water freeze (maybe its temperature going down so fast) but when you bring it out, it reaches its freezing point and THEN freezes but since this freezer is set to -5 C, thats not probably be the case.
     
  8. FAST6191

    Reporter FAST6191 Techromancer

    pip
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  9. test84
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    Member test84 GBAtemp's last ninja 2.

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    there should be a report button for scientific topics to FAST.
    i DO was sure that you missed this topic.

    i skimmed that link but are they related?
     
  10. kazumi213

    Member kazumi213 GBAtemp Regular

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    I will try to explain this, but I lack a bit of english technical words.

    Since you live in Japan, your water is probably heavily treated to make it drinkable. It is not "pure" water, but a solution. A water solution freezes at a lower temperature than pure water. The new freezing point depends on the solution concetration. The more concentrated, the lower the new freezing point. In your case is concentrated enough to have a freezing point lower than -5 ºC, so the water doens't freeze inside your freezer.

    Before trying to explain the inside freezing (thin inner layer of ice) when you bring it out I need to know if the bottle has to be open for this to happen or it also happens with a closed bottle.
     
  11. Mortenga

    Member Mortenga GBAtemp Regular

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    I hope your mother dies of cancer.
     
  12. Lyuse

    Lyuse Newbie

    He does not live in Japan
     
  13. notnarb

    Member notnarb Not narbing it up

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    Did the water bottle have a popped collar? That increases the effects of being supercool
     
  14. test84
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    Member test84 GBAtemp's last ninja 2.

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    supercool is different from this case as i explained earlier in this topic.

    and yes, I dont live in Japan.
     
  15. kazumi213

    Member kazumi213 GBAtemp Regular

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    It doesn't really matter if you live in Japan. I assumed that based on your flag. Wherever you live, the water you pour into the bottle is a solution concentated enough to have a freezing point lower than -5 ºC. This water is common in coastal regions with limited access to sweet water (from mountains, underground streams).

    Anyway, how about the freezing happening before or after you open the bottle when you bring it out of the freezer?
     
  16. test84
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    Member test84 GBAtemp's last ninja 2.

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    i dont remember that
     
  17. kazumi213

    Member kazumi213 GBAtemp Regular

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    Just to finish this question I will assume the freezing inside the bottle happens after opening the it, which leads to the easiest explanation.

    The air in your room contains water vapor to some extent (usually measured as the relative humidity). Contrary to the water in the bottle, the vapor water is "pure", having a higher freezing point (depends on the atmospheric pressure, at 1 atm or 760 mmHg it is around 0.4 ºC, the lower the pressure, the lower the freezing point).

    When you open the bottle, the room water vapor contacts the water surface inside the bottle. The water surface (at around -5 ºC) is cold enough to condensate the vapor (which becomes liquid "pure" water) and quickly freeze it forming the thin layer/fragments of ice you see on the surface.
     
  18. Shuny

    Member Shuny I'm in yr forum, reading yr postz

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    So, how to reproduce supercooling effect easily ? [​IMG]
     
  19. fischju

    Member fischju Rehabilitated Jaywalker

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    Buh, try the opposite. Put a cup of distilled water into a microwave with a cup of tap water (seperate, of course). Turn it on until the latter boils - you now have super heated water in the first container. Adding something will make it boil (rapidly and violently)
    (Also, never do that. I will not be liable when you burn your skin off)
     

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