Question

In ${\mathrm{PCl}}_5$, the three $\mathrm{P}-\mathrm{Cl}$ bonds in the plane are called as ______.

Answer 1

${\mathrm{PCl}}_5$ structure:

• In Phosphorus pentachloride ${\mathrm{PCl}}_5$, the atomic number of phosphorus is $15$.
• So, its electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^3$.
• The five valence electrons of phosphorus are shared with one electron each from five chlorine atoms.
• So, phosphorus undergoes ${\mathrm{sp}}^3\mathrm{d}$ hybridization and geometry will be trigonal bipyramidal.
• In ${\mathrm{PCl}}_5$ , all $\mathrm{P}-\mathrm{Cl}$ bonds are not the same.
• Two $\mathrm{P}-\mathrm{Cl}$ bonds are longer and less stable, these bonds are known as axial bonds.
• The other three $\mathrm{P}-\mathrm{Cl}$ bonds are more stable and are known as equatorial bonds.
• In the axial bonds, the greater will be the bond pair-bond pair repulsion.

Hence, the three $\mathrm{P}-\mathrm{Cl}$ bonds in a plane are called equatorial bonds.