In solid state `PCl_(5)`, exists as ionic solid i.e., `[X]^(+), [Y]^(-)` shapes of `X^(+) and Y^(-)` are respectively

Options

A. Tetrahedral, Pyramidal
B. Tetrahedral, Octahedral
C. Octahedral, Linear
D. Octahedral, Trigonal bipyramidal

Answer

To solve the question regarding the shapes of the ions in solid-state PCl5, we need to analyze the ionic forms of PCl5, which are PCl4+ and PCl6-. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Ionic Forms
PCl5 can exist in the solid state as two ions:
- PCl4+ (denoted as X+)
- PCl6- (denoted as Y-)

### Step 2: Determine the Valence Electrons of Phosphorus
Phosphorus (P) has 5 valence electrons. This is crucial for understanding the bonding and hybridization in both ions.

### Step 3: Analyze the X+ Ion (PCl4+)
1. **Charge Analysis**: PCl4+ means that phosphorus has lost one electron. Therefore, it has 4 valence electrons remaining.
2. **Bonding**: It forms 4 bonds with chlorine atoms.
3. **Hybridization**: With 4 bond pairs, the hybridization is sp³.
4. **Shape**: The geometry corresponding to sp³ hybridization is tetrahedral.

### Step 4: Analyze the Y- Ion (PCl6-)
1. **Charge Analysis**: PCl6- means that phosphorus has gained one electron. Therefore, it has 6 valence electrons.
2. **Bonding**: It forms 6 bonds with chlorine atoms.
3. **Hybridization**: With 6 bond pairs, the hybridization is sp³d².
4. **Shape**: The geometry corresponding to sp³d² hybridization is octahedral.

### Final Answer
- The shape of X+ (PCl4+) is **tetrahedral**.
- The shape of Y- (PCl6-) is **octahedral**.

### Summary
- **X+ (PCl4+)**: Tetrahedral
- **Y- (PCl6-)**: Octahedral