What type of orbital hydridisation is considered on P in `PCl_5` ?

Options

A. `sp^3d`
B. `dsp^3`
C. `sp^3d^2`
D. `d^2sp`

Answer

To determine the type of orbital hybridization of phosphorus (P) in the molecule PCl₅, we can follow these steps:

### Step 1: Identify the Central Atom
In the molecule PCl₅, phosphorus (P) is the central atom, surrounded by five chlorine (Cl) atoms.

### Step 2: Determine the Valence Electrons
Phosphorus is in group 15 of the periodic table and has 5 valence electrons.

### Step 3: Draw the Lewis Structure
In PCl₅, phosphorus forms single bonds with five chlorine atoms. Each Cl atom contributes one electron to form a bond with phosphorus. Thus, phosphorus uses all five of its valence electrons to form five sigma bonds with the chlorine atoms.

### Step 4: Calculate the Steric Number
The steric number is calculated using the formula:
\[ \text{Steric Number} = \text{Number of Sigma Bonds} + \text{Number of Lone Pairs} \]

In PCl₅:
- Number of sigma bonds = 5 (one for each P-Cl bond)
- Number of lone pairs on phosphorus = 0

Thus, the steric number is:
\[ \text{Steric Number} = 5 + 0 = 5 \]

### Step 5: Determine the Hybridization
The hybridization can be determined based on the steric number:
- A steric number of 5 corresponds to sp³d hybridization.

### Final Answer
The type of orbital hybridization considered on phosphorus in PCl₅ is **sp³d**.

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