The suggested molecular orbital electronic configuration of Co is : `KK (sigma_2s)^2 (sigma _(2s))^2, (pi_(2px))^2 (pi_(2py))^2 (sigma_(2pz))^2`.
Experimentally determined bond length in CO and `CO^+` are 112.8 pm and 111.5 pm . This suggest that

Options

A. the given molecular orbital electronic configuration is correct
B. the energy of `sigma_(2pz)`, is less than the energies of `pi_(2p_x)` , and `pi_(2p_y)` which are equal in energy
C. the energies of `pi_(2p_x)` and `pi_(2p_y)` are not equal
D. none of these

Explanation

To solve the question regarding the molecular orbital electronic configuration of CO and the bond lengths of CO and CO⁺, we will analyze the information step by step.

### Step 1: Understand the Molecular Orbital Configuration
The given molecular orbital electronic configuration for CO is:
- \( \sigma_{2s}^2 \)
- \( \sigma^*_{2s}^2 \)
- \( \pi_{2px}^2 \)
- \( \pi_{2py}^2 \)
- \( \sigma_{2pz}^2 \)

This configuration indicates that CO has a total of 10 valence electrons (2 from each of the \( \sigma \) and \( \pi \) orbitals).

### Step 2: Calculate the Bond Order
The bond order can be calculated using the formula:
\[ \text{Bond Order} = \frac{(N_b - N_a)}{2} \]
where \( N_b \) is the number of electrons in bonding orbitals and \( N_a \) is the number of electrons in antibonding orbitals.

From the configuration:
- Bonding electrons (\( N_b \)): \( 2 (\sigma_{2s}) + 2 (\pi_{2px}) + 2 (\pi_{2py}) + 2 (\sigma_{2pz}) = 8 \)
- Antibonding electrons (\( N_a \)): \( 2 (\sigma^*_{2s}) = 2 \)

Thus, the bond order is:
\[ \text{Bond Order} = \frac{(8 - 2)}{2} = \frac{6}{2} = 3 \]

### Step 3: Analyze the Bond Lengths
The bond lengths given are:
- CO: 112.8 pm
- CO⁺: 111.5 pm

The bond length is inversely related to bond order. A higher bond order typically results in a shorter bond length.

### Step 4: Compare the Bond Lengths
Since the bond length of CO⁺ (111.5 pm) is shorter than that of CO (112.8 pm), it suggests that the bond order of CO⁺ is higher than that of CO.

### Step 5: Conclusion
The decrease in bond length from CO to CO⁺ indicates that removing an electron (which likely comes from an antibonding orbital) increases the bond order, thus shortening the bond length.

### Final Answer
The data suggests that the bond order of CO⁺ is greater than that of CO, leading to a shorter bond length in CO⁺.

---