Given the Lewis structure of the nitrate ion (NO_3^-), where one oxygen atom is double-bonded to nitrogen and the other two are single-bonded with a negative charge, what is the formal charge on the double-bonded oxygen atom?

• A. 0
• B. -1
• C. -2
• D. +1

Answer: (A)

Verified step by step guidance

1. Recall the formula for calculating formal charge: \(\text{Formal Charge} = \text{Valence Electrons} - \text{Nonbonding Electrons} - \frac{1}{2} \times \text{Bonding Electrons}\).
2. Identify the number of valence electrons for oxygen, which is 6 because oxygen is in group 16 of the periodic table.
3. Count the nonbonding (lone pair) electrons on the double-bonded oxygen atom in the Lewis structure. Since it is double-bonded, it typically has two lone pairs (4 electrons).
4. Count the bonding electrons around the double-bonded oxygen. A double bond consists of 4 bonding electrons.
5. Substitute these values into the formal charge formula: \$6 - 4 - \frac{1}{2} \times 4$, then simplify to find the formal charge on the double-bonded oxygen atom.