Which of the following best describes an organic molecule with a carbonyl functional group?

• A. A molecule containing a ${\mathrm{CH}}_3$ group
• B. A molecule containing a ${\mathrm{COOH}}_1$ group
• C. A molecule containing a $C=O$ group
• D. A molecule containing a ${\mathrm{NH}}_2$ group

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what a carbonyl functional group is. A carbonyl group consists of a carbon atom double-bonded to an oxygen atom, represented as \(C=O\).
2. Step 2: Review the options given and identify which contains the carbonyl group. The options include groups like \(CH_3\), \(COOH_1\), \(C=O\), and \(NH_2\).
3. Step 3: Recognize that \(CH_3\) is a methyl group, which does not contain a carbonyl group.
4. Step 4: Note that \(COOH\) (carboxyl group) contains a carbonyl group as part of its structure, but the question asks specifically for the carbonyl functional group itself, which is \(C=O\).
5. Step 5: Understand that \(NH_2\) is an amino group and does not contain a carbonyl group. Therefore, the best description of an organic molecule with a carbonyl functional group is one containing the \(C=O\) group.