The number of lone pairs on Chlorine atom in `CIO^(-), CIO_(2)^(-), CIO_(3)^(-), ClO_(4)^(-)` ions are 

Options

A. `0,1,2,3`
B. `1,2,3,4`
C. `4,3,2,1`
D. `3,2,1,0`

Answer

To determine the number of lone pairs on the chlorine atom in the ions \( ClO^{-} \), \( ClO_{2}^{-} \), \( ClO_{3}^{-} \), and \( ClO_{4}^{-} \), we can follow these steps:

### Step 1: Determine the Valence Electrons of Chlorine
Chlorine (Cl) has an atomic number of 17, and its electronic configuration is \( [Ne] 3s^2 3p^5 \). This means it has 7 valence electrons (2 from the \( 3s \) subshell and 5 from the \( 3p \) subshell).

### Step 2: Calculate the Total Number of Valence Electrons for Each Ion
- **For \( ClO^{-} \)**:
- Chlorine has 7 valence electrons.
- Oxygen has 6 valence electrons, and there is 1 extra electron due to the negative charge.
- Total = \( 7 + 6 + 1 = 14 \) valence electrons.

- **For \( ClO_{2}^{-} \)**:
- Total = \( 7 + (2 \times 6) + 1 = 20 \) valence electrons.

- **For \( ClO_{3}^{-} \)**:
- Total = \( 7 + (3 \times 6) + 1 = 26 \) valence electrons.

- **For \( ClO_{4}^{-} \)**:
- Total = \( 7 + (4 \times 6) + 1 = 32 \) valence electrons.

### Step 3: Draw Lewis Structures and Count Lone Pairs
1. **For \( ClO^{-} \)**:
- Chlorine forms one single bond with oxygen.
- The remaining electrons: \( 14 - 2 = 12 \) electrons left for lone pairs.
- Chlorine will have 3 lone pairs (6 electrons) and 1 bond with oxygen.
- **Lone pairs = 3**.

2. **For \( ClO_{2}^{-} \)**:
- Chlorine forms two single bonds with two oxygen atoms.
- The remaining electrons: \( 20 - 4 = 16 \) electrons left for lone pairs.
- Chlorine will have 2 lone pairs (4 electrons) and 2 bonds with oxygen.
- **Lone pairs = 2**.

3. **For \( ClO_{3}^{-} \)**:
- Chlorine forms three bonds with three oxygen atoms (one of which is a double bond).
- The remaining electrons: \( 26 - 6 = 20 \) electrons left for lone pairs.
- Chlorine will have 1 lone pair (2 electrons) and 3 bonds with oxygen.
- **Lone pairs = 1**.

4. **For \( ClO_{4}^{-} \)**:
- Chlorine forms four bonds with four oxygen atoms (all double bonds).
- The remaining electrons: \( 32 - 8 = 24 \) electrons left for lone pairs.
- Chlorine will have 0 lone pairs (all electrons are used in bonding).
- **Lone pairs = 0**.

### Summary of Lone Pairs
- \( ClO^{-} \): 3 lone pairs
- \( ClO_{2}^{-} \): 2 lone pairs
- \( ClO_{3}^{-} \): 1 lone pair
- \( ClO_{4}^{-} \): 0 lone pairs

### Final Answer
The number of lone pairs on the chlorine atom in the ions \( ClO^{-}, ClO_{2}^{-}, ClO_{3}^{-}, ClO_{4}^{-} \) are **3, 2, 1, and 0** respectively.

---