Question

Compare the description of the localized electron model (Lewis structure) with that of the molecular orbital model for the bonding in$\mathbf{\text{NO}}$,${\mathbf{\text{NO}}}^{\mathbf{+}}$, and${\mathbf{\text{NO}}}^{\mathbf{-}}$. Account for any discrepancies between the two models.

Short answer

Localized electron model explains formation of $\sigma$and$\mathrm{\pi }$ bonds by overlapping orbitals. In molecular orbital model the new bonding and antibonding orbitals will be formed and filled with valence electrons

Step-by-step solution

Concept Introduction

A Lewis structure is a diagram that depicts a molecule's covalent bonds and lone electron pairs. The octet rule governs Lewis structures

Lewis Structure for each compound

Localized electron model includes forming of $\sigma$and$\mathrm{\pi }$ bonds by overlapping orbitals of each atom in the molecule.

Each molecule will form one $\sigma$bond overlapping $s$orbitals and one$\mathrm{\pi }$ bond overlapping$\text{p}$ orbitals. Molecule will form one addition $\mathrm{\pi }$bond in its resonat structure.

Molecular orbital model suggests forming of new molecular bonding and antibonding orbitals that are filled with valence electrons.

The electron configuration for molecule$\text{NO}$ isrole="math" localid="1663767188837" ${\left({\sigma }_{2s}\right)}^2{\left(\sigma {*}_{2s}\right)}^2{\left({\mathrm{\pi }}_{2p}\right)}^4{\left({\sigma }_{2p}\right)}^2{\left(\mathrm{\pi }{*}_{2p}\right)}^1$ .

The electron configuration for molecule${\text{NO}}^{-}$ is ${\left({\sigma }_{2s}\right)}^2{\left(\sigma {*}_{2s}\right)}^2{\left({\mathrm{\pi }}_{2p}\right)}^4{\left({\sigma }_{2p}\right)}^2{\left(\mathrm{\pi }{*}_{2p}\right)}^2$.

The electron configuration for molecule${\text{NO}}^{+}$ is ${\left({\sigma }_{2s}\right)}^2{\left(\sigma {*}_{2s}\right)}^2{\left({\mathrm{\pi }}_{2p}\right)}^4{\left({\sigma }_{2p}\right)}^2$.

Therefore, the production of $\sigma$and $\mathrm{\pi }$bonds is explained by overlapping orbitals in the localised electron model. New bonding and antibonding orbitals will be generated and filled with valence electrons in the molecular orbital model.