Draw All Possible Resonance Structures for SO2, SO3²⁻, and SO

Resonance Structures of SO₂

SO₂ (sulfur dioxide) has a total of three resonance structures. In the most commonly depicted structures, sulfur is in the center, double bonded to one oxygen and single bonded to another. The single-bonded oxygen atom has a formal negative charge, while the sulfur atom has a formal positive charge. The structures can be interchanged by moving the double bond from one oxygen to the other, giving us two more equivalent resonance forms.

Resonance Structures of SO₃^2–

For the sulfite ion, SO₃^2–, there are three resonance structures as well. In each resonance structure, sulfur is bonded to three oxygen atoms. One pair of electrons is shared in a double bond with one oxygen atom, while the other two are single bonds, each with a formal negative charge. The position of the double bond can shift among the three oxygen atoms, creating the different resonance forms of the ion.

Resonance Structures of SO

SO (sulfur monoxide) has fewer resonance structures due to its simplicity. Typically, it only has one major resonance form where sulfur has a double bond with oxygen. In this case, the electron distribution is straightforward as it shows a single double bond with no formal charges on the atoms. Additional minor contributors may exist but are often negligible.