The addition of a hydride ion (H^-) and a proton (H⁺) results in the reduction of a carbonyl group. The elimination of H^- and H⁺ from an alcohol results in the formation of a carbonyl group. For the following reaction:



Identify the atom of the carbonyl where the hydride ion is added. Explain.

• A. The hydride ion is added to the carbonyl oxygen because the carbonyl oxygen has a partial negative charge that attracts the negatively charged hydride ion.
• B. The hydride ion is added to the carbonyl carbon because the carbonyl carbon has a partial positive charge that attracts the negatively charged hydride ion.
• C. The hydride ion is added to the carbonyl oxygen because the carbonyl oxygen has a partial positive charge that attracts the negatively charged hydride ion.
• D. The hydride ion is added to the carbonyl carbon because the carbonyl carbon has a partial negative charge that attracts the negatively charged hydride ion.

Answer: (B)