Chapter 3, Problem 94AP

The molecular ion ${\text{S}}_{\text{3}}{\text{N}}_{\text{3}}^{-}$ has the cyclic structure

All $\text{S}-\text{N}$ bonds are equivalent.

(a) Give six equivalent resonance hybrid Lewis diagrams for this molecular ion.

(b) Compute the formal charges on all atoms in the molecular ion in each of the six Lewis diagrams.

(c) Determine the charge on each atom in the polyatomic ion, assuming that the true distribution of electrons is the average of the six Lewis diagrams arrived at in parts (a) and (b).

(d) An advanced calculation suggests that the actual charge resident on each N atom is $-0.\text{375}$ and on each S atom is $+0.0\text{41}$ . Show that this result is consistent with the overall $+\text{1}$ charge on the molecular ion.