Question

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

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

Answer 1

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

Common oxidation state of IVA group elements are +2, +4.

Non-existence of PbI4 can be explained on the basis of strong oxidising nature of $P{b}^{+}$.

The $I^{-}$ ions are reducing agents, i.e., in presence of this ion $P{b}_4^{+}$ ion is reduced to$P{b}_2^{+}$ ion.

+2 state becomes gradually more stable down the group & +4 state stability decreases from carbon to Lead due to inert pair effect.

So $Pb{I}_4$ is least stable and converts into $Pb{I}_2$.