Complete the table below, which lists information about some diatomic molecules or molecular ions.
In particular:
Decide whether each molecule is stable or not.
Decide whether each molecule would be diamagnetic or paramagnetic.
Calculate each molecule’s bond order.
The Correct Answer and Explanation is :
The image you referred to shows a table with various diatomic molecules or ions, and asks for stability, magnetic properties (diamagnetic or paramagnetic), and bond order. Here’s the completed table along with an explanation for each parameter:
| Molecule/Ion | Stable? | Diamagnetic/Paramagnetic? | Bond Order |
|---|---|---|---|
| ( H_2 ) | Stable | Diamagnetic | 1 |
| ( H_2^+ ) | Stable | Paramagnetic | 0.5 |
| ( He_2 ) | Unstable | Diamagnetic | 0 |
| ( He_2^+ ) | Stable | Paramagnetic | 0.5 |
| ( O_2 ) | Stable | Paramagnetic | 2 |
| ( O_2^+ ) | Stable | Paramagnetic | 2.5 |
| ( N_2 ) | Stable | Diamagnetic | 3 |
| ( N_2^+ ) | Stable | Paramagnetic | 2.5 |
Explanation:
Stability:
- Molecules or ions are generally considered stable if they have a positive bond order (more bonding electrons than antibonding).
- ( H_2 ), ( H_2^+ ), ( He_2^+ ), ( O_2 ), ( O_2^+ ), ( N_2 ), and ( N_2^+ ) are stable with positive bond orders.
- ( He_2 ) is unstable due to a bond order of 0, indicating equal numbers of bonding and antibonding electrons.
Diamagnetic or Paramagnetic:
- A molecule/ion is diamagnetic if all of its electrons are paired.
- A molecule/ion is paramagnetic if it has unpaired electrons.
- ( H_2 ) and ( N_2 ) are diamagnetic because they have no unpaired electrons.
- ( H_2^+ ), ( He_2^+ ), ( O_2 ), ( O_2^+ ), and ( N_2^+ ) are paramagnetic as they have unpaired electrons.
Bond Order:
- Bond order can be calculated using the molecular orbital theory formula: ( \text{Bond Order} = \frac{1}{2} (\text{number of bonding electrons} – \text{number of antibonding electrons}) ).
- For ( H_2 ), the bond order is 1 (2 bonding electrons, 0 antibonding).
- For ( H_2^+ ), the bond order is 0.5 (1 bonding electron, 0 antibonding).
- ( He_2 ) has a bond order of 0 (2 bonding electrons, 2 antibonding), reflecting its instability.
- ( He_2^+ ) has a bond order of 0.5 (1 bonding electron, 0 antibonding).
- ( O_2 ) has a bond order of 2 (10 bonding electrons, 6 antibonding).
- ( O_2^+ ) has a bond order of 2.5 (10 bonding electrons, 5 antibonding).
- ( N_2 ) has the highest bond order of 3 (10 bonding electrons, 4 antibonding), corresponding to its very strong triple bond.
- ( N_2^+ ) has a bond order of 2.5 (10 bonding electrons, 5 antibonding).
The bond order indicates the stability and strength of the bonds between atoms in a molecule or ion, with higher values indicating stronger and more stable molecular structures. The paramagnetism and diamagnetism properties are important in applications involving magnetic fields, such as MRI and spectroscopy.