Which of the following statements correctly describes the Lewis dot structure of neutral H2CO3 (carbonic acid)?

• A. The central carbon atom is bonded to two oxygen atoms, each double-bonded, and both hydrogens are attached directly to the carbon.
• B. The central carbon atom is bonded to two oxygen atoms, one single-bonded and one double-bonded, and both hydrogens are attached to the double-bonded oxygen.
• C. The central carbon atom is bonded to three oxygen atoms, all single-bonded, and both hydrogens are attached directly to the carbon.
• D. The central carbon atom is bonded to three oxygen atoms, with one oxygen double-bonded and the other two single-bonded; each single-bonded oxygen also has a hydrogen attached.

Answer: (D)

Verified step by step guidance

1. Identify the central atom in the molecule H2CO3, which is carbon (C), because carbon typically forms four bonds and acts as the central atom in carbon-containing acids.
2. Determine the number of oxygen atoms bonded to the carbon. In carbonic acid, carbon is bonded to three oxygen atoms.
3. Assign bonding types: one oxygen is double-bonded to carbon, while the other two oxygens are single-bonded to carbon. This arrangement satisfies carbon's four bonds (one double bond counts as two bonds, plus two single bonds).
4. Attach hydrogen atoms to the oxygen atoms that are single-bonded to carbon, not directly to carbon. This is because in acids like H2CO3, hydrogens are typically bonded to oxygen atoms, forming hydroxyl groups (-OH).
5. Verify the Lewis structure by counting valence electrons to ensure all atoms have complete octets (except hydrogen, which follows the duet rule) and that the molecule is neutral overall.