Question

In compounds of type $EC{l}_3$, where $E=B,P,As\text{or}Bi$, the $Cl-E-Cl$ bond angles for different $E$ are in the order:

• A. $B>P=As=Bi$
• B. $B>P>As>Bi$
• C. $B<P=As=Bi$
• D. $B<P<As<Bi$

Answer 1

The correct option is B $B>P>As>Bi$

In $BC{l}_3$, $B$ is $s{p}^2$ hybridised.
Hence, the bond angle is ${120}^0$.

In $PC{l}_3,AsC{l}_3\text{and}BiC{l}_3$, the central atom is $s{p}^3$ hybridised. $P,As$ and $Bi$ belong to the same group.
We know that, bond angle decreases down the group.

Hence, the overall order of bond angles is $B>P>As>Bi$.