Question

Explain how sulphur exists in the +2 oxidation state.

Answer 1

1. Sulphur has a valence shell configuration of ns² np⁴ with two unpaired electrons in the ground state that allows the formation of +2 oxidation state.
2. In +2 state, sulphur undergoes sp³ hybridisation, forming a tetrahedral shape with two bonds and two lone pairs.
3. It can form only two bonds in the ground state, so +2 oxidation state is possible but less stable compared to +4 and +6.
4. Higher oxidation states (+4, +6) involve excitation of electrons to vacant d-orbitals, but +2 exists in the ground state with two bonds.

Thus, sulphur exists in the +2 oxidation state by using its two unpaired electrons to form two bonds with sp³ hybridisation and two lone pairs on the atom.