Given the structure of the acetate ion, CH3COO-, what is the hybridization of the central carbon atom (the one double-bonded to one oxygen and single-bonded to another oxygen)?

• A. sp
• B. sp3
• C. sp2
• D. sp3d

Answer: (C)

Verified step by step guidance

1. Identify the central carbon atom in the acetate ion, which is bonded to two oxygen atoms and one methyl group (CH3).
2. Determine the number of regions of electron density (bonding and lone pairs) around the central carbon atom. Each single bond, double bond, and lone pair counts as one region.
3. For the acetate ion's central carbon, count the bonds: one single bond to the methyl group, one double bond to an oxygen, and one single bond to the other oxygen. This totals three regions of electron density.
4. Recall that three regions of electron density around a central atom correspond to an \(sp^{2}\) hybridization, which involves mixing one s orbital and two p orbitals.
5. Conclude that the central carbon atom in the acetate ion is \(sp^{2}\) hybridized because it forms three sigma bonds arranged in a trigonal planar geometry.