We are being asked to identify the resonance forms that describe the distribution of electrons in carbonate ion, CO32− ion.
We will have to draw the Lewis Structure of CO32− first.
Step 1: Determine the central atom in this molecule.
• C is less electronegative than O.
• C is the central atom and is bonded to the 3 other O atom
Step 2: Calculate the total number of valence electrons present.
Group Valence Electrons
C 4A 4 valence e‑ x 1
O 6A 6 valence e- x 3
= 22 valence e‑
-2 charge +2 e-
Total = 24 valence e-
Step 3: Draw the Lewis Structure for the molecule
• O and C → prefers to have complete octet (8 e- around them)
Write resonance forms that describe the distribution of electrons in each of these molecules or ions.
carbonate ion, CO32−