calculate the bond order for NO2+ ion, regarding all the resonance structures
The Correct Answer and Explanation is:
To calculate the bond order for the NO2+\text{NO}_2^+NO2+ ion, we need to consider its molecular structure and resonance. Here’s a step-by-step breakdown:
Step 1: Lewis Structure
For the NO2+\text{NO}_2^+NO2+ ion:
- Nitrogen (N) has 5 valence electrons, and each oxygen (O) has 6 valence electrons.
- The ion has a positive charge, so it has one fewer electron (total valence electrons = 5 (from N) + 2×6 (from O) − 1 (positive charge) = 16 electrons).
- In the most common Lewis structure, nitrogen is in the center, double-bonded to both oxygen atoms, with a lone pair on each oxygen.
Step 2: Resonance Structures
The NO2+\text{NO}_2^+NO2+ ion exhibits resonance. There are two major resonance structures:
- Structure 1: One oxygen has a double bond with nitrogen, and the other has a single bond. The singly bonded oxygen carries a negative charge, while nitrogen carries a positive charge.
- Structure 2: The positions of the bonds and charges are flipped.
Both of these structures contribute equally to the actual bonding in the molecule.
Step 3: Bond Order Calculation
Bond order is calculated using the following formula:Bond Order=Number of bonding electrons−Number of antibonding electrons2\text{Bond Order} = \frac{\text{Number of bonding electrons} – \text{Number of antibonding electrons}}{2}Bond Order=2Number of bonding electrons−Number of antibonding electrons
In this case:
- The number of bonding electrons in each resonance structure is 8 (from the double bonds).
- There are no antibonding electrons because we have a stable bonding configuration.
Thus, the bond order can be calculated as:Bond Order=82=4\text{Bond Order} = \frac{8}{2} = 4Bond Order=28=4
Step 4: Conclusion
For NO2+\text{NO}_2^+NO2+, considering the resonance structures, the bond order is 2, as the molecule is in between two resonance forms where each nitrogen-oxygen bond has partial double bond character. The bond order is closer to 2 because the electron distribution is more uniform.
The bond order of the NO2+\text{NO}_2^+NO2+ ion is 2, indicating that the bonding is stronger than in NO2\text{NO}_2NO2, where the bond order is 1.5.
