Question

what is the hybridization of the central atom in the phosphorus pentachloride (pcl₅) molecule?

Explanation:

Step1: Determine the valence - electron number of central atom

Phosphorus (P) is in Group 5A, so it has 5 valence electrons.

Step2: Determine the number of bonding pairs

In $PCl_5$, P forms 5 single bonds with 5 Cl atoms, so there are 5 bonding pairs.

Step3: Calculate the steric number

The steric number = number of bonding pairs+ number of lone - pairs. Since there are no lone - pairs on P in $PCl_5$, the steric number = 5 + 0=5.

Step4: Determine the hybridization

When the steric number is 5, the hybridization of the central atom is $sp^3d$.

Answer:

$sp^3d$