Chemistry - CHEMICAL BONDING Question with Solution | TestHub

In the given reaction, (X) is PF₃ and (Z) is PF₆⁻. Phosphorus has 9 orbitals in its valence shell ($n=3$: one $3s$, three $3p$, and five $3d$). In PF₃, phosphorus uses 4 orbitals (3 for bonds, 1 for a lone pair), leaving 5 vacant $3d$ orbitals. In PF₆⁻, it uses 6 orbitals for bonding (sp³d² hybridization), leaving 3 vacant $3d$ orbitals. The sum of vacant orbitals is $5+3=8$.