Deduce the oxidation number of S in the following species : i. SO2ii.

1.	Deduce the oxidation number of S in the following species : i. SO2ii. \(SO_4^{2-}\)
Answer» i. SO₂ is a neutral molecule. ∴ Sum of oxidation numbers of all atoms of SO₂ = 0 ∴ (Oxidation number of S) + 2 × (Oxidation number of O) = 0 ∴ Oxidation number of S + 2 × (- 2) = 0 ∴ Oxidation number of S in SO₂ = 0 – (- 4) ∴ Oxidation number of S in SO₂ = +4 ii. \(SO_4^{2-}\) is an ionic species. ∴ Sum of the oxidation numbers of all atoms of \(SO_4^{2-}\) = – 2 ∴ (Oxidation number of S) + 4 × (Oxidation number of O) = – 2 ∴ Oxidation number of S in \(SO_4^{2-}\) = – 2 – 4 × (-2) = – 2 + 8 ∴ Oxidation number of S in \(SO_4^{2-}\) = +6

Deduce the oxidation number of S in the following species : i. SO2ii. \(SO_4^{2-}\)

Answer»

i. SO₂ is a neutral molecule.

∴ Sum of oxidation numbers of all atoms of SO₂ = 0

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

∴ Oxidation number of S + 2 × (- 2) = 0

∴ Oxidation number of S in SO₂ = 0 – (- 4)

∴ Oxidation number of S in SO₂ = +4

ii. \(SO_4^{2-}\) is an ionic species.

∴ Sum of the oxidation numbers of all atoms of \(SO_4^{2-}\) = – 2

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

∴ Oxidation number of S in \(SO_4^{2-}\) = – 2 – 4 × (-2) = – 2 + 8

∴ Oxidation number of S in \(SO_4^{2-}\) = +6