H_{2}__S__O_{4}

Oxidation number of H = +1

Oxidation number of O = −2

H_{2}SO_{4} is a neutral molecule.

∴ Sum of the oxidation numbers of all atoms of H_{2}SO_{4} = 0

∴ 2 × (Oxidation number of H) + (Oxidation number of S) + 4 × (Oxidation number of O) = 0

∴ 2 × (+1) + (Oxidation number of S) + 4 × (–2) = 0

∴ Oxidation number of S + 2 – 8 = 0

**∴ Oxidation number of S in H**_{2}SO_{4} = +6