What is the formal charge on the sulfur atom in sulfur trioxide #SO_3#?

1 Answer
Sep 16, 2016

Answer:

Good question. In most treatments the formal charge is #+2#.

Explanation:

Sulfur assumes a #+VI# oxidation state in the acid anhydride sulfur trioxide, and of course has the same oxidation state in sulfuric acid.

#(O=)S^(2+)(-O^-)_2#

Most chemists would settle for the given representation.

The molecule is of course trigonal planar with #D_(3h)# symmetry.