Question

Account for the following: $PbO_{2}$ is a stronger oxidizing agent than $SnO_{2}$.

Answer 1

Post-transition metals like lead, tin, bismuth, thallium, etc., exhibit inert gas effect, i.e., the electrons located in the "outermost shell" of the atomic orbital remains unionized in these metals.

Although, the oxidation states of both $Pb{ O }_{ 2 }$ and $Sn{ O }_{ 2 }$ is the same at +4, the lower state of oxidation of ${ Pb }^{ +2 }$ is more stable which converts ${ Pb }^{ +4 }$ to ${ Pb }^{ +2 }$ rapidly due to its strong oxidation property.

Wherein tin, the ${ Sn }^{ +4 }$ state is "more stable" than ${ Sn }^{ +2 }$ oxidation state, due to its weak oxidation property.