Question

Given below are two statements:
Statement $I:$ The $E^{\circ }$ value for $C{e}^{4+}/C{e}^{3+}$ is $+1.74\text{V}$.
Statement $II:$ $Ce$ is more stable in $C{e}^{4+}$ state than $C{e}^{3+}$ state.
In the light of the above statements, choose the correct answer from the options given below:

• A. Both statement $I$ and statement $II$ are correct
• B. Statement $I$ is incorrect but statement $II$ is correct
• C. Both statement $I$ and statement $II$ are incorrect
• D. Statement $I$ is correct but statement $II$ is incorrect

Answer 1

The correct option is D Statement $I$ is correct but statement $II$ is incorrect

$C{e}^{4+}+e^{-}\to C{e}^{3+}$
$E^{\circ }=1.74\text{volt}$
As the $E^{\circ }$ value here is positive, the reduction of $C{e}^{4+}$ to $C{e}^{3+}$ is feasible.
Though $C{e}^{4+}$ has a noble gas electronic configuration, but to remove $4$ electrons from $Ce$ we need to provide large amount of energy, thus $C{e}^{3+}$ is more stable than $C{e}^{4+}$.