How would you find the oxidation number for SO4^2-?

1 Answer
Nov 9, 2015

Oxidation of sulfur in sulfate is #VI^+#

Explanation:

Oxidation number is the charge left on the central atom when all the bonding pairs of electrons are removed, with the charge going to the most electronegative atoms. If I do this for sulfate I get #S^(6+)# and #4# #xx# #O^(2-)#.

What about thiosulfate anion, #S_2O_3^(2-)#; here oxygen retains the #-II# oxidation state. What about the sulfurs?