Which general formula represents a ketone?

Which general formula represents a ketone?

• A. R-CHO
• B. R-COOH
• C. R-O-R
• D. R-CO-R

Answer: (D)

Ketones are defined by a carbonyl group (C=O) where the carbonyl carbon is attached to two carbon-containing groups. This gives the general formula R-CO-R, with R representing any alkyl or aryl group, which can be the same or different. For example, acetone is CH3-CO-CH3, illustrating the carbonyl flanked by two carbon substituents. This differs from an aldehyde, which has only one carbon substituent and a hydrogen on the carbonyl carbon (R-CHO). A carboxylic acid has a carbonyl attached to a hydroxyl group (R-COOH). An ether has two carbon groups bonded to oxygen without a carbonyl (R-O-R). Therefore, the general formula for a ketone is R-CO-R.

Ketones are defined by a carbonyl group (C=O) where the carbonyl carbon is attached to two carbon-containing groups. This gives the general formula R-CO-R, with R representing any alkyl or aryl group, which can be the same or different. For example, acetone is CH3-CO-CH3, illustrating the carbonyl flanked by two carbon substituents.

This differs from an aldehyde, which has only one carbon substituent and a hydrogen on the carbonyl carbon (R-CHO). A carboxylic acid has a carbonyl attached to a hydroxyl group (R-COOH). An ether has two carbon groups bonded to oxygen without a carbonyl (R-O-R). Therefore, the general formula for a ketone is R-CO-R.