In `IC l_4^(Ө)` , the shape is square planer. The number of bond pair-lone pair repulsion at `90^@` are :

Options

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

Answer

To solve the question regarding the number of bond pair-lone pair repulsions at \(90^\circ\) in \(ICl_4^-\), we can follow these steps:

### Step 1: Determine the Lewis Structure of \(ICl_4^-\)
- Iodine (I) has 7 valence electrons. Since the ion has a negative charge, it gains an additional electron, giving it a total of 8 valence electrons.
- Each chlorine (Cl) contributes 1 valence electron. With 4 chlorine atoms, that adds 4 more electrons.
- Therefore, the total number of valence electrons in \(ICl_4^-\) is \(8 + 4 = 12\) electrons.

### Step 2: Arrange the Electrons in the Lewis Structure
- Place iodine in the center and surround it with 4 chlorine atoms.
- Each Cl-I bond uses 2 electrons, so 4 bonds use \(4 \times 2 = 8\) electrons.
- This leaves \(12 - 8 = 4\) electrons, which will be placed as lone pairs on the iodine atom.

### Step 3: Identify Lone Pairs and Bond Pairs
- In the Lewis structure, iodine has 4 bond pairs (one for each Cl) and 2 lone pairs.
- The shape of \(ICl_4^-\) is square planar due to the arrangement of the bond pairs and lone pairs.

### Step 4: Analyze the Geometry and Repulsions
- In a square planar geometry, the bond pairs are in the same plane, and the lone pairs are positioned above and below this plane.
- The bond pairs are at \(90^\circ\) to each other.

### Step 5: Count the Bond Pair-Lone Pair Repulsions
- Each lone pair will repel the bond pairs.
- The first lone pair will create repulsions with all four bond pairs, resulting in 4 repulsions.
- The second lone pair will also create repulsions with all four bond pairs, resulting in another 4 repulsions.

### Step 6: Calculate Total Repulsions
- Total repulsions due to lone pairs at \(90^\circ\) = \(4\) (from the first lone pair) + \(4\) (from the second lone pair) = \(8\).

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

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