Question

Assertion :$TeB{r}_4$ and $PoB{r}_4$ are quite stable while $SB{r}_4$ and $SeB{r}_4$ are unstable Reason: Inert pair effect is greater in tetra bromides of $S$ and $Se$ than in $Te$ and $Po$.

• 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. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

$SB{r}_4$ and $SeB{r}_4$ are unstable on account of steric effect. Four bulky bromine atoms cannot be accommodated around small atoms of $S$ and $Se$, Tellurium ($Te$) and Polonium ($Po$) are relatively larger and can readily accommodate four large Br or I atoms. Inert pair effect becomes insignificant in the case of $6^{th}$ group and $7^{th}$ group elements. So, Assertion is correct and Reason is incorrect..