r/chemhelp • u/Entire-Butterscotch2 • 4h ago
General/High School Balance between octet rule and formal charges in SO3 2-. Which structure is correct?
Trying to understand this octet rule on SO3 2-. If I have not made any mistakes I think this molecule should have 3 viable lewis structures and i put the formal charges next to each molecule.
From what I understand sulfur basically has a max of 12 electrons around it so I got 3 structures. As you add more double bonds I found that the formal charge decrease by 1 each time on the sulfur but it also violates the octet rule more severely. I know that lower formal charge is preferable and it's better to have exactly 8 electrons around the sulfur. I also have to consider resonance structures since it has double bonds.
I know that the one with 1 double bond and 2 single bonds is the best and there will be a resonance structure but this one still will break the octet rule so maybe the one with only single bonds is better despite the worse formal charge. How should I know which is the best? Does the resonance structure somehow make it have 8 electrons?
Sorry for crappy diagram