p-Block Elements-I - Result Question 10
####10. In compounds of type $E Cl _3$, where $E=B, P, As$ or $Bi$, the angles $Cl-E-Cl$ for different $E$ are in the order
(1999, 2M)
(a) $B>P=As=Bi$
(b) $B>P>As>Bi$
(c) $B<P=As=Bi$
(d) B $<$ P $<$ As $<$ Bi
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Answer:
Correct Answer: 10. (b)
Solution:
- In $BCl _3$, bond angle $=120^{\circ}$.
In $PCl _3, AsCl _3$ and $BiCl _3$, central atom is $s p^{3}$ hybridised. Since $P, As$ and $Bi$ are from the same group, bond angle decreases down the group. Hence, overall order of bond angle is :
$$ B>P>As>Bi $$