Question

${Pb}^{4+}$ salts are better oxidizing agent agents, while ${Ge}^{2+}$ salts are better reducing agents. Explain.

Answer 1

By inert pair effect, the stability order is:

${Pb}^{4+}<{Pb}^{2+}$

${Ge}^{4+}>{Ge}^{2+}$.

Hence, ${Pb}^{4+}+{2e}^{-}⟶{Pb}^{2+}$ and ${Ge}^{2+}⟶{Ge}^{4+}+{2e}^{-}$ both are spontaneous towards more stable ions $(\Delta G^{\circ }<0)$. ${Pb}^{4+}$ can be easily reduced to ${Pb}^{2+}$ and thus is an oxidising agent. ${Ge}^{2+}$ can be easily oxidised and thus is a reducing agent.