In the Lewis structure of the sulfate ion (SO_4^{2-}), what is the formal charge on the oxygen atom that is doubly bonded to the sulfur atom?

• A. -1
• B. 0
• C. -2
• D. +1

Answer: (B)

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. Determine the number of nonbonding (lone pair) electrons on the oxygen atom that is doubly bonded to sulfur. In this case, the oxygen has two lone pairs, so 4 nonbonding electrons.
4. Count the bonding electrons around this oxygen. Since it is double bonded to sulfur, it shares 4 bonding electrons (2 bonds × 2 electrons each).
5. Substitute these values into the formal charge formula: \$6 - 4 - \frac{1}{2} \times 4$, and simplify to find the formal charge on the doubly bonded oxygen atom.