# Homework Help: What is the format for ionic lewis structure w/ resonance?

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1. Feb 20, 2015

### needingtoknow

1. The problem statement, all variables and given/known data

I need to draw NH4NO2 which is an ionic compound.

3. The attempt at a solution

NH4 is fairly straightforward to draw, with one N in the middle and four H surrounding, and no lone pairs. The problem comes with NO2- which is one nitrogen bonded to two oxygens. However, one of the bonds is a double bond which alternates back and forth between the two oxygens (I know this is a simplified way of explaining but it is just makes it easier to explain what I have so far). There is a lone pair on the nitrogen and 6 electrons around the oxygen that only has a single bond to the nitrogen while there is only 4 electrons around the oxygen that has the double bond with the nitrogen. I have never seen an example before of an ionic lewis structure where one of the ions is a resonance structure AND also with all of the electrons on the atoms shown as well and I was wondering if there is a certain way to draw this sort of structure or do I just place the 2 resonance structures next to the NH4? Thank you

2. Feb 20, 2015

### Quantum Defect

You will sometimes see resonance indicated with dashed/dotted lines for the second bonds.

I think that the original Lewis dot structures did not include the idea of resonance structures, so if you want to be true to G. N. Lewis, you could simply pick one to show, maybe with a note that you know that there are resonance structures.

It is interesting to look at the original paper that outlined the dot structure picture. It is from 1916, which is not that long ago. The paper includes some discussions of the idea of a cubical atom (trying to make sense of the 8 valence for many elements).
http://scarc.library.oregonstate.edu/coll/pauling/bond/papers/corr216.3-lewispub-19160400.html

I like the scanned image above, because this particular reprint of the paper belonged to Linus Pauling!