The correct answer is option 4, dsp3.
To understand why, we need to analyze the structure of the PCI5 molecule. Trigonal bipyramidal geometry consists of three equatorial atoms in the same plane and two axial atoms perpendicular to the plane. In PCI5, the central phosphorus atom is bonded to five chlorine atoms.
The formation of a trigonal bipyramidal structure implies the involvement of five hybrid orbitals. The hybridization of atomic orbitals involves the combination of different orbitals to form new orbitals that are utilized in bonding.
In the case of PCI5, the phosphorus atom`s outer shell consists of three electron pairs and two unpaired electrons in its valence shell. To accommodate these electron pairs and achieve optimal angles between the atoms, the phosphorus atom must undergo dsp3 hybridization. This means that three of the phosphorus atom`s valence orbitals (3s, 3p, and 4p) along with one d orbital (4d) are hybridized to form five dsp3 hybrid orbitals. These orbitals then overlap with the chlorine atoms to form the five PCI5 molecule bonds.
Therefore, option 4, dsp3, correctly represents the hybridization of p orbitals in