R-CHO represents which functional group?

R-CHO represents which functional group?

• A. Alcohol
• B. Ketone
• C. Carboxylic acid
• D. Aldehyde

Answer: (D)

Aldehydes are identified by a carbonyl carbon that is at the end of a carbon chain and is bonded to one hydrogen. In the notation R-CHO, the carbonyl carbon is attached to R on one side and to a hydrogen on the other, which is exactly the defining feature of an aldehyde. That terminal position and the presence of the formyl group (CHO) make it an aldehyde. For contrast, an alcohol would show an -OH group, a ketone would have the carbonyl carbon bonded to two carbon groups (R-CO-R'), and a carboxylic acid would have a -COOH group. Hence, R-CHO corresponds to the aldehyde functional group.

Aldehydes are identified by a carbonyl carbon that is at the end of a carbon chain and is bonded to one hydrogen. In the notation R-CHO, the carbonyl carbon is attached to R on one side and to a hydrogen on the other, which is exactly the defining feature of an aldehyde. That terminal position and the presence of the formyl group (CHO) make it an aldehyde.

For contrast, an alcohol would show an -OH group, a ketone would have the carbonyl carbon bonded to two carbon groups (R-CO-R'), and a carboxylic acid would have a -COOH group. Hence, R-CHO corresponds to the aldehyde functional group.