Question

Identify the species having one \(\pi\)-bond and maximum number of canonical forms from the following:

• A. SO\(_3\)
• B. O\(_2\)
• C. SO\(_2\)
• D. CO\(_3^{2-}\)

Hint:

The more resonance structures a molecule can have, the more stable it is, as electron density is spread out over the molecule.

Answer 1

The Correct Option is D

Step 1: {Analysis of Canonical Forms}
Canonical forms represent the various resonance structures of a molecule, indicating electron delocalization. The species exhibiting the highest number of canonical forms possesses the most stable resonance structure. 
Step 2: {Analysis of Compounds} 
SO\(_3\) exhibits three resonance structures but lacks a \(\pi\)-bond between sulfur and oxygen in any of them.
O\(_2\) displays two resonance structures with a single \(\pi\)-bond between the oxygen atoms but does not achieve the maximum count of canonical forms.
SO\(_2\) possesses two resonance structures, but this count also does not maximize the number of canonical forms.
CO\(_3^{2-}\) shows three resonance structures, each featuring a \(\pi\)-bond and delocalized electrons among the carbon and oxygen atoms. 
The carbonate ion (CO\(_3^{2-}\)) demonstrates the greatest number of canonical forms.
Therefore, the correct selection is (D).