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Separating salt from water

  1. Aug 27, 2011 #1


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    Why can’t I separate salt from water with a centrifuge, or simply by letting it sit for some time? Salt water is a homogeneous mixture, not a compound. So the salt and the water are not chemically bonded. Why don’t the denser NaCl molecules sink to the bottom of the H20 molecules?
  2. jcsd
  3. Aug 27, 2011 #2


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    NaCl are not in form of molecules, they are dissociated (not that it answers your question).

    Notion of density doesn't make much sense for a single molecule. Even if it was making sense, effects of molecular collisions (due to thermal motion of molecules) are orders of magnitude higher that effects of gravity.
  4. Aug 27, 2011 #3


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    Thanks Borek!
  5. Aug 28, 2011 #4
    Salt and water are homogeneous solutions , yes and NaCl can easily dissolve in water because of its low electrostatic single bond force .

    Water easily dissolves it . It is a true solution cannot be seen , cannot be collected through permeable membrane or filter paper .

    No matter of centrifugal force , it cannot be separated .
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