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Homework Help: The average separation between H2O molecules in pure water

  1. May 30, 2012 #1
    1. The problem statement, all variables and given/known data

    I can't answer to that question, and I don't know how to. I have to calculate the average separation between H2O molecules in pure water.

    2. Relevant equations

    The diameter of the molecule is 0.29 nm

    I think we can use the bohr equation to resolve it? r = (ε0*h2) / (π*m*e2)

    I also found this : ω (which is the average spacing) = 1/n = 4π/3=r03 (from here)

    3. The attempt at a solution

    I don't know.- I don't want the answer just some clue to get the answer. :)

    Thank you.
    Last edited: May 30, 2012
  2. jcsd
  3. May 30, 2012 #2
    Using the density and the mass per molecule, you can figure out the number of molecules per, say 10 x 10 x 10 nm....
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