What is the formal charge on each singly bonded oxygen atom in the Lewis structure of the carbonate ion (CO_3^{2-})?

• A. -2
• B. +1
• C. 0
• D. -1

Answer: (D)

Verified step by step guidance

1. Identify the oxygen atoms in the carbonate ion (CO_3^{2-}) and note which ones are singly bonded to the central carbon atom. In the Lewis structure of CO_3^{2-}, there is one carbon atom bonded to three oxygen atoms, with one oxygen typically double bonded and the other two singly bonded.
2. Recall the formula for calculating formal charge: \(\text{Formal Charge} = \text{Valence Electrons} - \text{Nonbonding Electrons} - \frac{1}{2} \times \text{Bonding Electrons}\).
3. Determine the number of valence electrons for oxygen, which is 6, since oxygen is in group 16 of the periodic table.
4. Count the nonbonding (lone pair) electrons on the singly bonded oxygen atom. Typically, a singly bonded oxygen in CO_3^{2-} has three lone pairs, so 6 nonbonding electrons.
5. Count the bonding electrons shared with carbon for the singly bonded oxygen. Since it is singly bonded, there are 2 bonding electrons. Then apply the formula: \$6 - 6 - \frac{1}{2} \times 2$ to find the formal charge on the singly bonded oxygen.