Q24 E - Chemistry (OpenStax)

Question

For the carbonate ion, \({\rm{C}}{{\rm{O}}_{\rm{3}}}^{{\rm{2 - }}}\), draw all of the resonance structures. Identify which orbitals overlap to create each bond.

Step-by-Step Solution

Answer

In all resonance structures, carbon is \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) hybridised. Carbon's hybridised \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) orbitals overlap with oxygen's hybridised \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) orbitals to form an o bond, and carbon's unhybridized \({\rm{p}}\) orbital overlaps with oxygen's unhybridized \({\rm{p}}\) orbital to form a \({\rm{\pi }}\) bond. Carbon's unhybridized \({\rm{p}}\) orbital delocalizes throughout the molecule, resulting in resonance structures.

Step 1: Define bond energy

The amount of energy required to break apart a mole of molecules into its component atoms is known as bond energy (E) .

Step 2: Explanation

\({\rm{C}}{{\rm{O}}_{\rm{3}}}^{{\rm{2 - }}}\) resonance structures,

Therefore, in all of the resonance configurations, carbon is \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) hybridised. The o bond is formed when the hybridised \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) orbitals of carbon overlap with the hybridised \({\rm{s}}{{\rm{p}}^{\rm{2}}}\) orbitals of oxygen, while the \({\rm{\pi }}\) bond is formed when the unhybridized \({\rm{p}}\) orbitals of carbon overlap with the unhybridized \({\rm{p}}\) orbitals of oxygen. Carbon's unhybridized \({\rm{p}}\) orbital delocalizes across the entire molecule, resulting in resonance configurations.