H2SO4
We know, Oxidation number of H = +1
Oxidation number of O = -2
Let oxidation number of sulfur be X. Then ,
2 x (+1) + X + 4 x (-2) = 0
Solving we get,
+2 + X - 8 = 0
X = +6
Determine the oxidation number of sulphur in H2SO4.