Which is a ketone? a. CH3COCH3 b. CH3COOH c. C2H5OH d. CH3CHO
The Correct Answer and Explanation is :
The correct answer is (a) CH₃COCH₃, which is a ketone.
Explanation of Ketones
Ketones are a type of organic compound characterized by a carbonyl group (C=O) attached to two carbon atoms. In the molecular structure of ketones, the carbonyl group (C=O) is positioned within the carbon chain rather than at the end. This placement of the carbonyl group is what differentiates ketones from other organic compounds, such as aldehydes and carboxylic acids.
Identifying CH₃COCH₃ as a Ketone
- The formula CH₃COCH₃ is known as acetone, a simple ketone.
- In acetone, the central carbonyl group (C=O) is bonded to two methyl groups (CH₃) on each side.
- This configuration meets the criteria of a ketone because the carbonyl carbon is connected to two carbon atoms rather than hydrogen or oxygen atoms.
Why the Other Options Are Not Ketones
- CH₃COOH: This is acetic acid, a carboxylic acid, not a ketone. It has a carbonyl group, but the carbonyl is bonded to a hydroxyl group (OH), forming a carboxylic acid rather than a ketone.
- C₂H₅OH: This is ethanol, an alcohol, not a ketone. It has an -OH group attached to a carbon but lacks a carbonyl group (C=O), which is essential for a ketone.
- CH₃CHO: This is acetaldehyde, an aldehyde, not a ketone. In aldehydes, the carbonyl group is attached to at least one hydrogen atom, which distinguishes them from ketones, where the carbonyl carbon is attached to two carbons.
Conclusion
Thus, CH₃COCH₃ (acetone) is the only compound among the options that fits the structural requirements of a ketone. This specific structure has a significant role in chemistry, especially in solvents, biochemical processes, and industrial applications.