Number of sigma and pi bonds in `ClO_(2)^(-)` ion

Options

A. `2sigma and 2sigma `
B. `3 sigma and 3pi`
C. ` 3 sigma and 2pi`
D. `2 sigma and 3pi`

Answer

To determine the number of sigma and pi bonds in the \( \text{ClO}_2^{-} \) ion, we can follow these steps:

### Step 1: Determine the Lewis Structure of \( \text{ClO}_2^{-} \)
- The first step is to calculate the total number of valence electrons available for the ion. Chlorine (Cl) has 7 valence electrons, and each oxygen (O) has 6 valence electrons. Since there are two oxygen atoms, we have:
\[ \text{Total valence electrons} = 7 + (2 \times 6) + 1 = 20 \]
(The extra 1 is due to the negative charge on the ion.)

### Step 2: Arrange the Atoms
- In the Lewis structure, chlorine is the central atom, and it is bonded to two oxygen atoms.

### Step 3: Form Bonds
- To satisfy the octet rule, we can form one double bond between chlorine and one of the oxygen atoms, and a single bond with the other oxygen atom. This gives:
- One \( \text{Cl} = \text{O} \) double bond
- One \( \text{Cl} - \text{O} \) single bond

### Step 4: Count Sigma and Pi Bonds
- In the double bond (\( \text{Cl} = \text{O} \)):
- There is **1 sigma bond** and **1 pi bond**.
- In the single bond (\( \text{Cl} - \text{O} \)):
- There is **1 sigma bond**.

### Step 5: Total Count
- Now, we can sum up the total number of sigma and pi bonds:
- Total sigma bonds = 1 (from double bond) + 1 (from single bond) = **2 sigma bonds**
- Total pi bonds = 1 (from double bond) = **1 pi bond**

### Final Answer
- Therefore, the number of sigma bonds in \( \text{ClO}_2^{-} \) is **2**, and the number of pi bonds is **1**.

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