Which of the following are consequences of, or correctly explained by, the inert pair effect in group 14?

APb(IV) compounds are strong oxidising agents.
B $Pb X^{2 +}$ is less stable than $Pb X^{4 +}$ in compounds.
C $Sn X^{4 +}$ is a stronger oxidising agent than $Pb X^{4 +}$ .
D $PbI X_{4}$ does not exist at ordinary conditions as Pb(IV) oxidises $I X^{-}$ .

Answer: A, D

Reluctance of the

6 s^{2}

pair to bond makes Pb(II) more stable than Pb(IV), so Pb(IV) compounds readily oxidise others. That is why

Pb X^{4 +}

oxidises

I X^{-}

and

PbI X_{4}

cannot exist. Statements 2 and 3 reverse the trends: Sn(IV) is stable and a poor oxidiser. Statements 1 and 4 are correct.