Which of the following best represents the generic structure of an aldehyde?

• A. $R-\mathrm{COOH}$
• B. $R-\mathrm{CO}-\mathrm{R\text{'}}$
• C. $R-C=O-H$
• D. $R-\mathrm{CHOH}$

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the functional groups involved. An aldehyde contains a carbonyl group (C=O) bonded to at least one hydrogen atom and one alkyl or aryl group (represented as R).
2. Step 2: Analyze each given structure to identify the functional groups: - R-COOH represents a carboxylic acid group. - R-CO-R' represents a ketone group. - R-CHOH represents an alcohol group attached to R. - R-CHO represents an aldehyde group, where the carbonyl carbon is bonded to R and a hydrogen atom.
3. Step 3: Recall the generic formula for an aldehyde is \(\mathrm{R-CHO}\), where the carbonyl carbon is double bonded to oxygen and single bonded to hydrogen.
4. Step 4: Confirm that the correct structure has the carbonyl carbon double bonded to oxygen and single bonded to hydrogen, which matches \(\mathrm{R-CHO}\).
5. Step 5: Conclude that the generic structure of an aldehyde is best represented by \(\mathrm{R-CHO}\), distinguishing it from carboxylic acids, ketones, and alcohols.