Question

Assertion :$Pb{Cl}_4$ is more stable than $Pb{Cl}_2$. Reason: $Pb{Cl}_4$ is a powerful oxidising agent.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect and Reason is correct

Answer 1

The correct option is D Assertion is incorrect and Reason is correct

The inertness of s subshell electrons towards the bond formation is called inert pair effect or it can be said as the inactiveness of electrons present in outermost shell (i.e. ns unpaired and involve in bond formation is called inert pair effect. for example:

1) In 13 th group, thallium can exhibit +1 and+3 oxidation states but it is stable in +1 oxidation state only due to inert pair effect.

2) In 14 th group , lead shows both +2 and +4 oxidation states but it is stable in +2 oxidation state due to inert pair effect.

$Pb{Cl}_2$ is more stable than $Pb{Cl}_4$ or ${Pb}^{2+}$ is more stable than ${Pb}^{4+}$ (due to the inert pair effect)

$2e^{-}+{Pb}^{4+}⟶{Pb}^{2+}$ (Reduction) (Oxidising agent)