Question

In compound of the type $EC{l}_3$, where $E=B$, P, AS, or Bi, the angles Cl-E-Cl 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 $B>P>As>Bi$

$BC{l}_3$ is trigonal planar in structure and bond angles are ${120}^o$ each. $PC{l}_3,AsC{l}_3$, and $BiC{l}_3$ are pyramidal in shape with $s{p}^3$-hybridization.

In all of them, the bond angles are less than the normal tetrahedral angle of $109.28$', and also these bond angles decrease down the group.

Therefore, the correct order of bond angles is as follows:

$BC{l}_2>PC{l}_3>AsC{l}_3>BiC{l}_3$

Hence option $B$ is correct.