Question

Which of the following halides is least stable and has doubtful existence?

• A. $CC{l}_4$
• B. $Ge{I}_4$
• C. $Sn{I}_4$
• D. $Pb{I}_4$

Answer 1

The correct option is D $Pb{I}_4$

In $Pb{I}_4,$ the oxidation state of $Pb$ is $(+4)$.
We know, as we go down in periodic table, due to inert pair effect existence of higher oxidation state decreases.
$P{b}^{2+}$ state is more stable compared to $P{b}^{4+}$ state.
Hence, existence of $Pb{I}_4$ is doubtful and it is least stable compared to other halide.
Therefore, the correct option is (d).