H2SO4
Oxidation number of H = +1
Oxidation number of O = −2
H2SO4 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms of H2SO4 = 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 H2SO4 = +6