oxidation number for sulfate
T here is no oxidation number for compounds, only the elements within compounds. The charge of SO4 (sulfate) is 2-. The oxidation number of each oxygen is 2-.The oxidation number of the sulfur in this compound is 6+.here are four oxygen atoms in each sulfate ion, so t â¦ hat the total charge from oxygen is -8. This means that the oxidation number of sulfur must be +6, so that the total charges will sum to zero, as required for a compound. 3 people found this useful. Rnp 279.