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Energy required to ionize air

  1. Jul 22, 2009 #1
    Do you know which is the energy per mol required to ionize air? Once the air is ionized, does it recombine it´s charges so that after a while there is no ionized air at all? If this is the case, how long does it take for this to happen?
  2. jcsd
  3. Jul 22, 2009 #2
    Do you mean the VOLTAGE required for air break down? Or the energy required to remove a single electron from every atom in the mol?
  4. Jul 23, 2009 #3
    I mean the energy required to remove a single electron from every atom in the mol.
  5. Jul 25, 2009 #4


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    I'm not sure whether or not this is homework, but this might be most appropriately answered in the Chemistry forum. Dredging up some of my high school chemistry, the process for ionization requires you to first break the molecular bonds (the triple bonds of nitrogen, and double bonds of oxygen) and form free atoms. Then, you need to ionize them.

    Air is composed chiefly of nitrogen and oxygen (total 99%). I'd make a simplifying assumption and assume you have only nitrogen (79%) and oxygen (21%):

    Now, assume you have 1 mol of 'air' (0.79 mol of N2 and 0.21 mol of O2), figure out how much energy you need to break the bonds:
    http://www.webelements.com/nitrogen/bond_enthalpies.html [Broken]
    http://www.webelements.com/oxygen/bond_enthalpies.html [Broken]

    Now figure out how much energy you need to ionize all these nitrogen and oxygen atoms (how many mols of each?)

    Presto! Amount of energy required to ionize air. Please show your work.
    Last edited by a moderator: May 4, 2017
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