Question

Give reasons : $E{u}^{2+}$ is a good reducing agent.

Answer 1

A good reducing agent oxidises itself readily. $Eu$ is a lanthanide having electronic configuration $\left[Xe\right]4f^{7}5d^{1}6s^2$. In $+2$ oxidation state its configuration is $\left[Xe\right]4f^{7}5d^{1}6s^0$, while in $+3$ oxidation state its electronic configuration is $\left[Xe\right]4f^{7}5d^{0}6s^0$. Here the outermost shell is half filled which makes $E{u}^{+3}$ highly stable. Therefore, $E{u}^{+2}$ oxidises readily to give more stable $E{u}^{+3}$ and acts as a strong reducing agent.