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Homework Help: Melting points

  1. Apr 9, 2007 #1

    i am having a hard understanding melting points from my text book. can someone please explain to me how they work and how you can determine melting points in the periodic table?
  2. jcsd
  3. Apr 9, 2007 #2
    Can anyone help me with this:

    element solubility in water Melting

    NaF 0.042 988
    NaCl 0.357 801
    NaBr 1.16 755
    NaI 1.84 651

    Explain the decreasing melting point from NaF to NaI?

    I think it has to do with covalent and ionic bonds...because NaF is ionic it has a higher because its harder to pull the electrons apart and NaI more covalent so it has a lower melting point...am i close please help..!!
    Last edited: Apr 9, 2007
  4. Apr 10, 2007 #3
    Yeah, youre on the right track.
  5. Apr 10, 2007 #4


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    No, you are not on the right track....

    Bond energy tracks with ionic/covalent character but melting point is more related to the nature of the lattice that makes up the material. Neat, tightly packed lattices with equal size anions and cations will have a higher melting point than one with ions of different sizes. This is more important to melting point than the bond strength.

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