Question

In compounds of type ecl3 where e = b,p,as or bi the angle cl e cl for the different are in the order

Answer 1

B>P>As>Bi

In nitrogen family bond angle is maximum in the case of BCl3 (120) and minimum in the case of BiCl3 (97.5).

Answer 2

Answer:$BCl_3>PCl_3>AsCl_3>BiCl_3$

Explanation: According to VSEPR theory:

Number of electron pairs $=\frac{1}{2}[V+N-C+A]$

where,

V = number of valence electrons present in central atom

N = number of monovalent atoms

C = charge of cation

A = charge of anion

In $BCl_3$, B is the central atom and Cl are monovalent atoms.

Number of electron pairs $=\frac{1}{2}[3+3-0+0]=3$

The number of electron pairs is 3 that means the hybridization will be $sp^2$ and the molecular geometry will be trigonal planar. The bond angle will be 120°.

For $PCl_3$ , $AsCl_3$ and  $BiCl_3$

Number of electron pairs $=\frac{1}{2}[5+3-0+0]=4$

The number of electron pairs is 4 that means the hybridization will be $sp^3$ and the molecular geometry will be tetrahedral. The bond angle will be 109.5°.

But the bond angle decreases with decreasing electronegativity of the central atom which follows the order: P>As>Bi.