formal charge

[Cavalli_1H]

in the formal charge example we did in class, why is it again that he said the central sulfur should not have a charge, and that most central atoms don't have a charge?

[Kate Osborne 1H]

If each element in a compound has a formal charge of zero than it is the most stable form of that compound, and because a lot of compounds are stable they have a formal charge of zero on all the elements. The sulfur did not have a charge in the example given in class because oxygen is more electronegative than sulfur and should therefore carry the negative formal charge.

[Natalie Wang 1B]

Having a 0 formal charge is the most stable, so the Sulfur has a 0 formal charge. Of course, this causes two of the oxygen atoms bonded to sulfur to each have a formal charge of -1. This is fine because oxygen is already more electronegative than sulfur, so it attracts the electrons more. Even though two of the oxygen atoms in sulfate have formal charges of -1, this version of sulfate is the most stable.

[SMIYAZAKI_1B]

It is because of the electron affinity difference between oxygen and sulfur. Between sulfur and oxygen, oxygen has more stable structure when they have that charge in comparison to sulfur. Therefore, since compounds look for then most stable structure in most of the cases, oxygen should have the formal charge.