Question

What is the charge, and Lewis structure of the nitrate anion?

Answer 1

The nitrate ion, `NO_3^-`, has a SINGLE, FORMAL negative charge.

Explanation:

The sum of the individual oxidation numbers will be the charge on the ion. We thus have `N^(V+)+3xxO^(-II) = -I` as required. Note that Lewis structure of nitrate anion shows formal charge on THREE of the FOUR participating atoms: a positive charge on the central (quaternized) nitrogen atom, and negative charges on TWO of the oxygen atoms.

The Lewis structure is usually depicted as `(O=)stackrel(+)N(-O^(-))_2`, which bears a formal negative charge as required.