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Effect of intermolecular hydrogen bonding

  1. Apr 26, 2015 #1
    Effect of intermolecular hydrogen bonding is as follows
    hydrogen bonding.png
    I don't understand one point i.e how occurrence of liquid state is associated with intermolecular hydrogen bonding
    as intermolecular hydrogen bonding helps in closed packing of molecules it should give rise to solid state.
     
  2. jcsd
  3. Apr 26, 2015 #2

    Borek

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    Staff: Mentor

    And it finally does when the temperature gets low enough. But even when water is in the liquid form some molecules are linked by hydrogen bonds. Not all, and there is no lattice going throughout the liquid, but locally clusters of several molecules can be quite ordered.
     
  4. Apr 27, 2015 #3

    Quantum Defect

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    What you are looking at is probably a list of periodic trends for the oxygen family hydrides (H2O, H2S, H2Se, etc...) As you move up the column, the boiling points decrease. H2S is a gas at room temperature, you would predict (based upon the trend) that H2O would also be a gas, and have an even lower boiling point. The fact is that it is a liquid at room temperature and it has a very high boiling point. The reason for both of these observations is attibuted to the relatively strong interactions between the water molecules, compared with H2S, etc. and the rest of the members of the series. These strong interactions are called hydrogen bonds.
     
  5. Apr 28, 2015 #4

    epenguin

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    Plus anything you put into the water, polar or non polar, changes these structures or creates others. Around proteins for instance sometimes some water molecules are immobilized enough to be characterized as fixed structures by X-ray crystallography. Elementary and semi-elementary texts focus possibly overmuch on molecules alone when it is molecules in their solvent environment that are the thing to explain or the thing that explains IMHO. In short - never forget the solvent!
     
    Last edited: Apr 28, 2015
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