In the Lewis structure of the nitrate ion (NO_3^-), what is the formal charge on the oxygen atom that is singly bonded to nitrogen?

• A. 0
• B. -2
• C. +1
• D. -1

Answer: (D)

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. Determine the number of valence electrons for oxygen, which is 6 because oxygen is in group 16 of the periodic table.
3. Identify the number of nonbonding (lone pair) electrons on the singly bonded oxygen atom in the nitrate ion. Typically, this oxygen has three lone pairs, so count those electrons.
4. Count the bonding electrons shared between the singly bonded oxygen and nitrogen. Since it is a single bond, there are 2 bonding electrons.
5. Substitute these values into the formal charge formula to calculate the formal charge on the singly bonded oxygen atom.