Which of the following compounds contains a ketone functional group?

• A. Ethylamine ($C_2{H}_{7}N$)
• B. Acetic acid ($C_2{H}_4{O}_2$)
• C. Ethanol ($C_2{H}_{6}O$)
• D. Acetone ($C_3{H}_{6}O$)

Answer: (D)

Verified step by step guidance

1. Recall the definition of a ketone functional group: it consists of a carbonyl group (C=O) bonded to two carbon atoms. The general structure is R-CO-R', where R and R' are carbon-containing groups.
2. Examine each compound's structure to identify the presence or absence of the ketone functional group:
3. 1. Ethylamine (C\_2H\_7N) contains an amine group (-NH\_2) attached to an ethyl group, so it does not have a ketone.
4. 2. Acetic acid (C\_2H\_4O\_2) contains a carboxylic acid group (-COOH), which includes a carbonyl but is not a ketone because the carbonyl carbon is bonded to an -OH group, not two carbons.
5. 3. Ethanol (C\_2H\_6O) contains an alcohol group (-OH) attached to an ethyl group, so it does not have a ketone.
6. 4. Acetone (C\_3H\_6O) contains a carbonyl group bonded to two methyl groups, fitting the ketone functional group definition.