2) Below is the molecular orbital diagram for the fluorine molecule (F2) and images of several molecular orbitals that exist in this molecule. Fill the blanks below
a. The bond order for the F2 molecule is (enter a numeral).
b. The F2 molecule is
(paramagnetic/diamagnetic).
c. The molecular orbital diagram evidence of s/p mixing. (does/does not) exhibit
d. The molecular orbital image(s) labeled (A/B/C/D/E/F, choose all that apply) represent molecular orbitals formed from 2s atomic orbitals.
e. The molecular orbital image(s) labeled (A/B/C/D/E/F, choose all that apply) represent σ’ antibonding molecular orbitals.
The Correct Answer and Explanation is :
Let’s address each part of your question regarding the molecular orbital (MO) diagram for the fluorine molecule (F₂):
a. The bond order for the F₂ molecule is (enter a numeral).
The bond order is calculated using the formula:
[ \text{Bond Order} = \frac{1}{2} \times (\text{Number of electrons in bonding MOs} – \text{Number of electrons in antibonding MOs}) ]
For F₂, each fluorine atom contributes 7 valence electrons, totaling 14 electrons. In the MO diagram, these electrons fill the bonding and antibonding orbitals as follows:
- Bonding MOs: σ(2s)², σ*(2s)², σ(2p_z)², π(2p_x)², π(2p_y)²
- Antibonding MOs: π(2p_x)², π(2p_y)²
Calculating the bond order:
[ \text{Bond Order} = \frac{1}{2} \times (10 – 4) = \frac{1}{2} \times 6 = 3 ]
Therefore, the bond order for F₂ is 1.
b. The F₂ molecule is (paramagnetic/diamagnetic).
A molecule is paramagnetic if it has unpaired electrons and diamagnetic if all electrons are paired. In the F₂ molecule, the electrons occupy the bonding and antibonding orbitals as follows:
- Bonding MOs: σ(2s)², σ*(2s)², σ(2p_z)², π(2p_x)², π(2p_y)²
- Antibonding MOs: π(2p_x)², π(2p_y)²
All electrons are paired in these orbitals, indicating that F₂ is diamagnetic.
c. The molecular orbital diagram evidence of s/p mixing. (does/does not) exhibit.
In molecules with an atomic number greater than 7, such as F₂, the energy gap between the 2s and 2p orbitals is significant, leading to minimal mixing between these orbitals. Therefore, the F₂ molecular orbital diagram does not exhibit s/p mixing.
d. The molecular orbital image(s) labeled (A/B/C/D/E/F, choose all that apply) represent molecular orbitals formed from 2s atomic orbitals.
In the F₂ molecule, the 2s atomic orbitals combine to form:
- Bonding Molecular Orbital: σ(2s)
- Antibonding Molecular Orbital: σ*(2s)
These orbitals are typically labeled as σ(2s) and σ*(2s) in molecular orbital diagrams. Without the specific labels from the provided image, it’s challenging to assign them to A, B, C, D, E, or F.
e. The molecular orbital image(s) labeled (A/B/C/D/E/F, choose all that apply) represent σ’ antibonding molecular orbitals.
The term “σ’ antibonding” is not standard in molecular orbital theory. Antibonding molecular orbitals are typically labeled with an asterisk (), such as σ(2s) and σ*(2p_z). Without the specific labels from the provided image, it’s challenging to assign them to A, B, C, D, E, or F.
For a visual explanation of the F₂ molecular orbital diagram, you might find the following video helpful:
videoMolecular Orbital Diagram for F₂turn0search0