Question

11 mark for review for which of the following molecules are resonance structures necessary to describe the bonding satisfactorily? a so₂ b co₂ c of₂ d pf₃

Explanation:

Resonance structures are needed when a molecule can be represented by two or more Lewis - structures that differ only in the placement of electrons. In $SO_2$, sulfur has a lone pair and is double - bonded to one oxygen and single - bonded to the other. The double bond can be on either side of the sulfur, resulting in resonance. $CO_2$ has a linear structure with two double bonds and no resonance. $OF_2$ and $PF_3$ have single bonds and lone pairs and no resonance - like electron delocalization.

Answer:

A. $SO_2$