Use molecular orbital theory to complete the ground state electron configuration for each of the molecules

Use molecular orbital theory to complete the ground state electron configuration for each of the molecules.

Molecule

Ground state electron configuration

NF

(σ1s)(σ1s)(σ2s)(σ2s)(π2p)(σ2p)(π2p*)

NF+

(σ1s)(σ1s)(σ2s)(σ2s)(π2p)(σ2p)(π2p*)

NF−

(σ1s)(σ1s)(σ2s)(σ2s)(π2p)(σ2p)(π2p*)

Answer Bank

0

1

2

3

4

Determine the bond order of each of the molecules.

NF bond order:

NF+ bond order:

NF− bond order:

Classify each molecule according to its magnetic properties.

Diamagnetic Paramagnetic

Answer Bank

NF

NF+

NF−

The Correct Answer and Explanation is :

Molecular Orbital Theory Configurations for ( \text{NF}, \text{NF}^+, \text{NF}^- ):

The ground-state electron configuration of these molecules can be completed based on the molecular orbital (MO) diagram for heteronuclear diatomic molecules, considering nitrogen (( Z = 7 )) and fluorine (( Z = 9 )). The key orbital energy ordering for NF is as follows:
[
(\sigma_{1s})(\sigma_{1s}^)(\sigma_{2s})(\sigma_{2s}^)(\pi_{2p})(\sigma_{2p})(\pi_{2p}^*)
]

1. NF (neutral):
   Total electrons: ( 7 + 9 = 16 ).
   Configuration: ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^2 ).
2. ( \text{NF}^+ ):
   Total electrons: ( 16 – 1 = 15 ).
   Configuration: ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^1 ).
3. ( \text{NF}^- ):
   Total electrons: ( 16 + 1 = 17 ).
   Configuration: ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^2(\pi_{2p}^*)^1 ).

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Bond Order Calculation:

Bond order is calculated as:
[
\text{Bond order} = \frac{1}{2} \left( N_b – N_a \right)
]
where ( N_b ) = bonding electrons, ( N_a ) = antibonding electrons.

1. NF:
   ( N_b = 10 ) (σ1s, σ2s, π2p, σ2p), ( N_a = 6 ) (σ1s, σ2s).
   Bond order = ( \frac{1}{2}(10 – 6) = 2.0 ).
2. ( \text{NF}^+ ):
   ( N_b = 9 ), ( N_a = 6 ).
   Bond order = ( \frac{1}{2}(9 – 6) = 1.5 ).
3. ( \text{NF}^- ):
   ( N_b = 10 ), ( N_a = 7 ).
   Bond order = ( \frac{1}{2}(10 – 7) = 1.5 ).

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Magnetic Properties:

• Diamagnetic: Molecules with all electrons paired.
• Paramagnetic: Molecules with unpaired electrons.

1. NF: All electrons are paired → Diamagnetic.
2. ( \text{NF}^+ ): One unpaired electron in ( \sigma_{2p} ) → Paramagnetic.
3. ( \text{NF}^- ): One unpaired electron in ( \pi_{2p}^* ) → Paramagnetic.

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Summary:

1. Ground state configurations:

• NF: ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^2 )
• ( \text{NF}^+ ): ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^1 )
• ( \text{NF}^- ): ( (\sigma_{1s})^2(\sigma_{1s}^)^2(\sigma_{2s})^2(\sigma_{2s}^)^2(\pi_{2p})^4(\sigma_{2p})^2(\pi_{2p}^*)^1 )

1. Bond orders:

• NF: 2.0
• ( \text{NF}^+ ): 1.5
• ( \text{NF}^- ): 1.5

1. Magnetic properties:

• NF: Diamagnetic
• ( \text{NF}^+ ): Paramagnetic
• ( \text{NF}^- ): Paramagnetic