CBSE Class 12 · 2003 · Delhi Compartment · d and f Block ElementsVery Short Answer

Why is Ce⁴⁺ in aqueous solution a good oxidising agent?

Answer: E°(Ce⁴⁺/Ce³⁺) = +1.74 V — Ce⁴⁺ strongly prefers the stable +3 state (it can even oxidise water).

Solution

The +3 state is the stable state of cerium, so Ce

^{4 +}

has a strong tendency to gain an electron:

C e^{4 +} + e^{-} \to C e^{3 +}, E^{\circ} = + 1.74 V

This high positive potential (enough even to oxidise water) makes aqueous Ce

^{4 +}

an excellent oxidising agent.

CBSE Class 12 Board · 2003 · Delhi Compartment · Subjective