Question

In which of the following all the bonds are not of equal strength?

• A. $P{Cl}_5$
• B. ${SF}_6$
• C. ${SF}_4$
• D. ${BF}_3$

Answer 1

Answer: (A), (B), (C)

The correct options are
A $P{Cl}_5$
B ${SF}_6$
C ${SF}_4$

$PC{l}_5$,$S{F}_6$ and $S{F}_4$, in which all the bonds are not of equal strength.
(A): $PC{l}_5$ shows $s{p}^{3}d$ hybridisation in which three $P-Cl$ bonds lies in one plane making an angle of ${120}^o$ while remaining two $P-Cl$ bonds lies above and below the equatorial plane making an angle of ${90}^o$.
(B): $S{F}_6$ forms octahedral shaped molecule with $s{p}^3{d}^2$ hybridisation.It consists of two types of bonds with bond angles ${90}^o$ and ${180}^o$.
(C): $S{F}_4$ shows $s{p}^{3}d$ hybridisation.The geometry of $S{F}_4$ is seesaw with an asymmetric electron region distribution around the central atom.It consists of two types of bonds with bond angles ${90}^o$ and ${180}^o$.
(D): In $B{F}_3$, three bonds are equivalent and are ${120}^o$ apart. Therefore, the shape of $B{F}_3$ is trigonal and planar.