what is the bond order of carbon monoxide ?

Explanation

To find the bond order of carbon monoxide (CO), we can follow these steps:

### Step 1: Understand the concept of bond order
Bond order is a measure of the number of chemical bonds between a pair of atoms. It can be calculated using the formula:
\[ \text{Bond Order} = \frac{1}{2} \times (\text{Number of bonding electrons} - \text{Number of anti-bonding electrons}) \]

### Step 2: Determine the molecular orbital configuration of CO
To calculate the bond order, we first need to write the molecular orbital (MO) configuration of carbon monoxide. The MO configuration for CO is as follows:
- The electrons fill the molecular orbitals in the order of increasing energy.
- The configuration can be written as:
- \( \sigma_{1s}^2 \)
- \( \sigma_{1s}^*^2 \)
- \( \sigma_{2s}^2 \)
- \( \sigma_{2s}^*^2 \)
- \( \sigma_{2p_z}^2 \)
- \( \pi_{2p_x}^2 \)
- \( \pi_{2p_y}^2 \)
- \( \pi_{2p_x}^*^0 \)
- \( \pi_{2p_y}^*^0 \)

### Step 3: Count the bonding and anti-bonding electrons
From the MO configuration:
- **Bonding electrons**:
- \( \sigma_{1s}^2 \) contributes 2
- \( \sigma_{2s}^2 \) contributes 2
- \( \sigma_{2p_z}^2 \) contributes 2
- \( \pi_{2p_x}^2 \) contributes 2
- \( \pi_{2p_y}^2 \) contributes 2
- Total bonding electrons = 2 + 2 + 2 + 2 + 2 = 10

- **Anti-bonding electrons**:
- \( \sigma_{1s}^*^2 \) contributes 2
- \( \sigma_{2s}^*^2 \) contributes 2
- Total anti-bonding electrons = 2 + 2 = 4

### Step 4: Calculate the bond order
Now, we can substitute the values into the bond order formula:
\[ \text{Bond Order} = \frac{1}{2} \times (10 - 4) = \frac{1}{2} \times 6 = 3 \]

### Conclusion
The bond order of carbon monoxide (CO) is 3.

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