Which of the following will have pyramidal shape :-

Options

A. `[ClOF_(2)]^(+)`
B. `I Cl_(4)^(-)`
C. `[BrICl]^(-)`
D. All of these

Answer

To determine which of the given compounds has a pyramidal shape, we can use the concept of hybridization and the VSEPR (Valence Shell Electron Pair Repulsion) theory. Here’s a step-by-step solution:

### Step 1: Identify the Central Atom and Valence Electrons
For each compound, identify the central atom and count its valence electrons.

### Step 2: Apply the Formula for Hybridization
Use the formula:
\[ x = \frac{1}{2} \left( \text{Valence electrons of central atom} + \text{Number of surrounding monovalent atoms} + \text{Charge} \right) \]
- If there is a negative charge, add it.
- If there is a positive charge, subtract it.

### Step 3: Determine the Number of Lone Pairs
Calculate the number of lone pairs using:
\[ \text{Lone pairs} = x - \text{Number of bond pairs} \]
Where the number of bond pairs is equal to the number of surrounding atoms.

### Step 4: Determine the Shape
Using the number of bond pairs and lone pairs, determine the molecular geometry:
- If there are 3 bond pairs and 1 lone pair, the shape is pyramidal.
- If there are 4 bond pairs and 1 lone pair, the shape is seesaw.
- If there are 2 bond pairs and 3 lone pairs, the shape is linear.

### Example Analysis
1. **First Compound: ClF2**
- Central atom: Cl (7 valence electrons)
- Surrounding atoms: 2 F
- Charge: 0
- Calculation:
\[ x = \frac{1}{2} (7 + 2 + 0) = \frac{1}{2} (9) = 4.5 \text{ (round down to 4)} \]
- Lone pairs: \( 4 - 3 = 1 \) (3 bond pairs, 1 lone pair)
- Shape: Pyramidal

2. **Second Compound: ICl4⁻**
- Central atom: I (7 valence electrons)
- Surrounding atoms: 4 Cl
- Charge: -1
- Calculation:
\[ x = \frac{1}{2} (7 + 4 + 1) = \frac{1}{2} (12) = 6 \]
- Lone pairs: \( 6 - 4 = 2 \) (4 bond pairs, 2 lone pairs)
- Shape: Seesaw

3. **Third Compound: BrICl⁻**
- Central atom: I (7 valence electrons)
- Surrounding atoms: 2 Cl
- Charge: -1
- Calculation:
\[ x = \frac{1}{2} (7 + 2 + 1) = \frac{1}{2} (10) = 5 \]
- Lone pairs: \( 5 - 2 = 3 \) (2 bond pairs, 3 lone pairs)
- Shape: Linear

### Conclusion
The only compound that has a pyramidal shape is **ClF2**.