The nitrite ion, NO2−, is an atmospheric constituent formed during combustion processes.
(a) Construct every valid Lewis diagram for NO2− that satisfies the octet rule for each atom and shows all lone-pair electrons.
(b) For each Lewis diagram, calculate the formal charge on every atom and state the overall charge of the ion to confirm consistency.
(c) Explain why the structures drawn in part (a) are described as resonance forms rather than depicting rapid oscillations of double and single bonds.
(d) Draw a resonance hybrid for NO2−, clearly indicating partial bond orders and partial charges on the nitrogen and oxygen atoms.
(e) The gas-phase N–O bond in NO has an experimental length of 115 pm. Predict qualitatively whether the N–O bond length in NO2− will be shorter than, longer than, or intermediate between 115 pm and a typical N–O single bond (∼140 pm), and justify your answer using your resonance hybrid from part (d).