Hydarazoic acid, HN3, is not a fun compound to work with: not only does it have an irritating odor that is dan-gerous at concentrations of less than 1 ppm, but in solution it is potentially explosive. Assume the connectivity of atoms in the compounds is the following (a, b, and c are arbitrary indices to keep the N's straight):
Na-Nb-Nc-H
a) Draw the three most reasonable resonance structures of HN3. For each resonance form, give the formal charges of the nitrogen atoms and estimate the Na-Nb-Nc and Nb-Nc-H bond angles.
b) The measured Nb-Nc-H bond angle is 112 degress. Use VSEPR theory to select the resonance structure(s) that best describe the true structure of this molecule and predict the bond angle. Does your answer agree with experiment? Explain.
c) The two N-N bond lengths of HN3 have also been measured. Bsed on your answer to part (b), which of these possibilities would you expect? Why?
I. The Nb-Nc is shorter than the Na-Nb bond.
II. The Nb-Nc is longer than the Na-Nb bond.
III. The two N-N bonds have the same length.