Question

which of the following statements, if true, would support the claim that the no₃⁻ ion, represented above, has three resonance structures? a the no₃⁻ ion is not a polar species. b the oxygen - to - nitrogen - to - oxygen bond angles are 90°. c one of the bonds in no₃⁻ is longer than the other two. d one of the bonds in no₃⁻ is shorter than the other two.

Explanation:

In a molecule with resonance structures, the actual bond lengths are equal due to the delocalization of electrons. A non - polar species can be an indication of resonance as resonance often leads to a symmetrical distribution of charge. In $NO_3^-$, resonance causes the three N - O bonds to be equivalent in length and the molecule to be non - polar. Option B is incorrect as the bond angles in $NO_3^-$ are $120^{\circ}$ not $90^{\circ}$. Options C and D are incorrect because in $NO_3^-$ with resonance, all N - O bonds have the same length due to electron delocalization.

Answer:

A. The $NO_3^-$ ion is not a polar species.