Resonant Structures

[temaire]

1. The problem statement, all variables and given/known data
Draw at least one resonant structure of the nitrate ion in AgNO_{3}.



3. The attempt at a solution
Is this a possible resonant structure of the nitrate ion?

http://i34.tinypic.com/avo7iq.jpg

[BlueEight]

You want a Lewis Dot Structure of AgNO3, not just NO3-.

[Borek]

I don't think so - question asks for structure of nitrate ion, and in general structure of nitrate ion doesn't depend on the counterion.

temaire: resonant structure should have localized charge. How many valence electrons on N?

--
chemical calculators (http://www.chembuddy.com) - buffer calculator (http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator), concentration calculator (http://www.chembuddy.com/?left=CASC&right=concentration_and_solution_calculator)
www.titrations.info (http://www.titrations.info) - all about titration (http://www.titrations.info) methods

[temaire]

I think I see where I went wrong. My diagram has 12 valence electrons for N, while I'm supposed to have only 8. But how do resonant structures have localized charges? Shouldn't they have delocalized charges?

[Borek]

No, delocalized charge is effect of switching between resonant strutures. Charge is localized in any individual structure, but as molecule switches between them very fast, what we observe is charge that is delocalized.

--
chemical calculators (http://www.chembuddy.com) - buffer calculator (http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator), concentration calculator (http://www.chembuddy.com/?left=CASC&right=concentration_and_solution_calculator)
www.titrations.info (http://www.titrations.info) - all about titration (http://www.titrations.info) methods

[temaire]

So, if I was asked to come up with a resonant structure for the nitrate ion, I would have to include all of the possible lewis dot diagrams for nitrate ions with a certain number of single or double bonds?

[chemisttree]

Yes, indeed.