Question

resonance structures are needed to describe the bonding in which of the following? co₂ h₂o clf₃ hno₃ ch₄

Explanation:

Resonance structures describe delocalized electrons. $\text{CO}_2$ has two equivalent resonance forms (O=C=O ↔ O≡C-O⁻ with charge delocalization), but wait—correction: $\text{HNO}_3$ has delocalized π electrons across N and O atoms (resonance between structures with double bonds on different O atoms). $\text{CO}_2$’s bonds are equivalent due to resonance, but $\text{HNO}_3$ explicitly requires multiple resonance structures to represent its bonding accurately. Other molecules ($\text{H}_2\text{O}$, $\text{ClF}_3$, $\text{CH}_4$) have fixed single/double bonds without delocalization.

Answer:

HNO₃