CHEMISTRY · Multi-part · AP · Chemistry · Compound Structure and Properties · Compound Structure and Properties
Problem
Nitrogen dioxide, NO₂(g), is produced transiently in the atmosphere by lightning strikes. The molecule contains an odd number of total valence electrons and is known to exhibit resonance as well as an unpaired electron.
(a) Determine the total number of valence electrons that must be represented in a complete Lewis diagram for one molecule of NO₂.
(b) Draw all valid Lewis structures for NO₂ that satisfy the octet rule as fully as possible while accounting for the unpaired electron. Indicate the location of the unpaired electron in each structure.
(c) For each structure drawn in part (b), calculate the formal charge on every atom and clearly show your work.
(d) Identify which resonance contributor from part (b) makes the greatest overall contribution to the resonance hybrid. Justify your choice solely on the basis of formal charge distribution and placement of the unpaired electron.
(e) Predict how resonance influences the experimentally observed N–O bond lengths in NO₂ relative to a true single N–O bond and a true double N═O bond. Explain your reasoning.