Question

Assign reason for the following:

Ce³⁺ can be easily oxidised to Ce⁴⁺.

Answer 1

1. Cerium (Ce) has the electronic configuration [Xe] 4f¹ 5d⁰ 6s².
2. In the +3 oxidation state, Ce³⁺ has one electron in the 4f orbital ([Xe] 4f¹).
3. Oxidising Ce³⁺ to Ce⁴⁺ removes this 4f electron, resulting in the stable electronic configuration [Xe] 4f⁰.
4. The +4 oxidation state of cerium is highly stable due to the empty 4f orbital and favorable energy.

Hence, Ce³⁺ is easily oxidised to Ce⁴⁺ because removing the single 4f electron leads to a more stable, lower energy state.