What is the formal charge on the carbon atom in carbon monoxide (CO)?

• A. -1
• B. +1
• C. +2
• D. 0

Answer: (B)

Verified step by step guidance

1. Recall the formula for 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 carbon. Carbon is in group 14, so it has 4 valence electrons.
3. Examine the Lewis structure of CO. Carbon and oxygen are connected by a triple bond, and there is a lone pair on carbon. Count the nonbonding electrons on carbon (lone pairs) and the bonding electrons (shared in bonds).
4. Calculate the formal charge on carbon by substituting the values into the formula: subtract the number of nonbonding electrons on carbon and half the bonding electrons from the valence electrons of carbon.
5. Interpret the result: a positive formal charge indicates carbon has fewer electrons than its valence count, which matches the correct answer of +1.