I understand how the nitrite $\ce{NO2}$ ion can be formed and have a negative charge, but the nitrate $\ce{NO3}$ ion is confusing me. I made some simple drawings to try to explain what I don't understand:

enter image description here

Does the "electron from outside" that the oxygen receives, as indicated in the drawing, comes from the nitrogen atom? If so, then the N atom would be left with only 4 valence electrons instead of 5, thus being able to form another covalent bond with the extra oxygen, forming $\ce{NO3}$. Is this the correct line of thinking?


2 Answers 2


An organiker would look at it this way.

Nitrate resonance forms

An inorganiker might look at it as literal N(+5) with two double-bonded oxygens. It does redox as N(+5). Coordination structures are varied,

Nirate coordination

  • $\begingroup$ I was under the impression that organic chemists have a much greater tendency to expand octets than inorganic ones … $\endgroup$
    – Jan
    Dec 12, 2016 at 16:41

If you are thinking about it like literally adding O to the nitrite ion then yes, the two electrons the oxygen receives are from nitrogen. Imagine moving the nitrogen lone pair to the oxygen to give it a full octet and forming a single bond in the process. You will notice that the Lewis structures will match the "organiker" structures of Uncle Al.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.