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Homework Help: Covalency and Oxidation Number in Covalent Compounds

  1. Feb 14, 2013 #1
    1. The problem statement, all variables and given/known data


    What is the Co-valency / Oxidation number of Nitrogen in this Covalent compound ?

    2. Relevant equations

    I think the table of electronegativity might be useful

    3. The attempt at a solution

    Nitrogen must be "-3" since it is more electronegative than Chlorine.

    The correct answer is +3. How is that possible ?

    Clearly Nitrogen is more electronegative than chlorine.
  2. jcsd
  3. Feb 14, 2013 #2
    Chlorine is more electronegative than nitrogen. :)
  4. Feb 15, 2013 #3
    Nitrogen forms hydrogen bonds in its compounds with Hydrogen attached .

    Chlorine rarely forms any hydrogen bonds in any of its compounds .

    Here : Electronegativity scale.jpg
  5. Feb 15, 2013 #4
    Allen Scale? :confused:

    Pauling Scale is the one you need to use.
  6. Feb 15, 2013 #5
    hmm...doesn't Pauling scale gives us wrong values since according to pauling scale Chlorine being more Electronegative should form Hydrogen bonds .
  7. Feb 15, 2013 #6


    User Avatar

    Staff: Mentor

    As if it all mattered...

    First: oxidation numbers don't reflect any real property of the element, they are used just for electron accounting.

    Second: using electronegativity to predict anything is a quite fuzzy concept, more of a general indication than a hard rule, especially when the differences in electronegativity are small.

    Taking both things into account - don't be surprised you get inconsistent predictions trying to apply rule of thumb to border cases.
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