Formal charge question

[Emily Mei 1B]

In class today, we said the sulfate ion with the double bonds was the best representation based on formal charge. Why was this?

[Christian Fulinara 3H]

Having a low formal charge would mean that it is most likely to appear in comparison to other resonance structures.
"A low formal charge indicates that an atom has undergone only a small redistribution of electrons relative to the free atom. The structure with formal charges closest to zero typically has the lowest energy of all possible structures" (83).
Also, because sulfur does not follow the octet rule and can hold 6 bonds, having two double bonds and two single bonds was more stable, which is 6 bonds total.

[Christina Cen 2J]

The lower the formal charge is, the more stable the molecule is and the less likely it will form reactions. Since the model with double bonds has a lower formal charge, it has a higher stability and is a better representation.

[Diane Bui 2J]

Dr. Lavelle showed how moving from the structure with single bonds to the structure with double bonds resulted in lower formal charges for 2 of the oxygen atoms, going from -1 to 0. The structure with the lower formal charge indicates more stability and is therefore the best representation of the molecule.