The bond order in `CO_3^(2-)` ion between C - O is

Options

A. Zero
B. 0.88
C. 1.33
D. 2

Explanation

To find the bond order in the carbonate ion \( \text{CO}_3^{2-} \) between carbon (C) and oxygen (O), we can follow these steps:

### Step 1: Draw the Lewis Structure of \( \text{CO}_3^{2-} \)
- The carbonate ion has one carbon atom and three oxygen atoms. The carbon atom is the central atom.
- The total number of valence electrons is calculated as follows:
- Carbon contributes 4 electrons.
- Each oxygen contributes 6 electrons, and there are three oxygens: \( 3 \times 6 = 18 \) electrons.
- The ion has a charge of -2, which adds 2 more electrons.
- Total = \( 4 + 18 + 2 = 24 \) valence electrons.

### Step 2: Distribute the Electrons
- Place the carbon atom in the center and connect it to the three oxygen atoms with single bonds.
- After placing single bonds (3 bonds = 6 electrons), we have \( 24 - 6 = 18 \) electrons left.
- Distribute the remaining electrons to the oxygen atoms to satisfy the octet rule. Each oxygen will get 6 electrons (3 lone pairs), using up all 18 electrons.

### Step 3: Identify Resonance Structures
- The carbonate ion has resonance structures. The double bond can be between carbon and any one of the three oxygen atoms at a time.
- For example, one resonance structure can have a double bond between C and one O, while the other two O atoms have single bonds with a negative charge.

### Step 4: Count the Total Number of Bonds
- In each resonance structure, there are:
- 1 double bond (which counts as 2 bonds) and 2 single bonds (which count as 2 bonds).
- Therefore, in each resonance structure, there are a total of \( 2 + 1 + 1 = 4 \) bonds.

### Step 5: Count the Number of Resonance Structures
- There are three resonance structures for \( \text{CO}_3^{2-} \) (one for each oxygen being double bonded to carbon).

### Step 6: Calculate the Bond Order
- The bond order is calculated using the formula:
\[ \text{Bond Order} = \frac{\text{Total number of bonds}}{\text{Number of resonance structures}} \]
- Plugging in the values:
\[ \text{Bond Order} = \frac{4}{3} \approx 1.33 \]

### Conclusion
The bond order between carbon and oxygen in the carbonate ion \( \text{CO}_3^{2-} \) is approximately \( 1.33 \).

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