In `I Cl_(4)^("ϴ")`, shape is square planar. The number of bond pair – lone pair repulsion at `90^(@)` are:-

Options

A. 6
B. 4
C. 12
D. 8

Answer

To solve the question regarding the number of bond pair-lone pair repulsions in the square planar shape of \( ICl_4^{-} \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Central Atom and its Valence Electrons**:
- The central atom in \( ICl_4^{-} \) is iodine (I).
- Iodine has 7 valence electrons.

2. **Count the Valence Electrons from Chlorine Atoms**:
- Each chlorine (Cl) atom contributes 1 valence electron. Since there are 4 chlorine atoms, they contribute \( 4 \times 1 = 4 \) electrons.

3. **Account for the Negative Charge**:
- The negative charge on the ion \( ICl_4^{-} \) means we add 1 more electron.
- Therefore, the total number of valence electrons is:
\[ 7 \text{ (from I)} + 4 \text{ (from Cl)} + 1 \text{ (from charge)} = 12 \text{ valence electrons} \]

4. **Determine the Number of Hybrid Orbitals**:
- The number of hybrid orbitals is equal to the total number of valence electrons divided by 2 (since each bond uses 2 electrons).
- Thus, the number of hybrid orbitals is:
\[ \frac{12}{2} = 6 \text{ hybrid orbitals} \]

5. **Identify the Hybridization**:
- With 6 hybrid orbitals, the hybridization is \( sp^3d^2 \).

6. **Count Bond Pairs and Lone Pairs**:
- In \( ICl_4^{-} \), there are 4 bond pairs (from the 4 \( I-Cl \) bonds).
- The remaining hybrid orbitals will be lone pairs. Since there are 6 hybrid orbitals and 4 are used for bonding, the number of lone pairs is:
\[ 6 - 4 = 2 \text{ lone pairs} \]

7. **Determine the Shape**:
- The arrangement of 4 bond pairs and 2 lone pairs leads to a square planar shape.

8. **Calculate Bond Pair-Lone Pair Repulsions**:
- In a square planar geometry, the lone pairs are positioned opposite each other, and each lone pair will repel the bond pairs.
- Each lone pair will have repulsions with the 4 bond pairs.
- Therefore, for 2 lone pairs, the total number of bond pair-lone pair repulsions is:
\[ 4 \text{ (from the first lone pair)} + 4 \text{ (from the second lone pair)} = 8 \]

### Final Answer:
The number of bond pair-lone pair repulsions at \( 90^\circ \) in \( ICl_4^{-} \) is **8**.

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