Lewis Structure for SO2 [ENDORSED]

[Austin Ho 1E]

Hey guys,

Recently I've come across 2 different lewis structures for SO2 - one with the Oxygens double bonded to the Sulfur, and the other with 1 Oxygen double bonded and 1 Oxygen single bonded. According to formal charge, we should use the first one with both Oxygens double bonded, but I saw sometimes that the other version (that also has resonance) is used. I think the reason why the second structure with resonance is used is because Oxygen is more electronegative than Sulfur and thus pulls a bonding pair close to itself.

Anyways, does anyone know which one to use? I've seen both in past midterm examples and am confused as to use which one.

[Chem_Mod]

The lowest energy structure is the one with double bonds on both bonds. However, the other two structures are not so high energy as to be unstable, nor do they violate any octet rules, etc. All of these 3 structures contribute to the true resonance structure of SO₂. The lowest energy (2 double bonds) structure is the most stable and contributes the most.