Final answer:
To identify a C=O functional group, you must examine the atoms bonded to the carbonyl carbon. Aldehydes have at least one hydrogen connected to this carbon, ketones have two carbons, carboxylic acids have a hydroxyl group, and esters have a carbonyl carbon bonded to an oxygen which is in turn bonded to another carbon.
Step-by-step explanation:
To determine which C=O functional group is present in a given molecule, we should look at the surrounding atoms bonded to the carbonyl carbon (the carbon with the double bond to oxygen). The functional groups related to the carbonyl group (carbon-oxygen double bond) include:
- Aldehydes - The carbonyl carbon is bonded on one side to a hydrogen and on the other side to a carbon (except for formaldehyde where it is bonded to two hydrogens).
- Ketones - The carbonyl carbon is bonded to two other carbon atoms.
- Carboxylic acids - The carbonyl carbon is also bonded to a hydroxyl group (-OH).
- Esters - The carbonyl carbon is bonded to an oxygen that is also bonded to another carbon (denoted as -CO₂R).
Without the specific structure of a molecule, determining the exact functional group isn't possible. However, based on the definitions:
- If the molecule's carbonyl carbon is bonded to at least one hydrogen, it contains an aldehyde group.
- If there are two carbon groups attached to the carbonyl carbon with no hydrogens, it is a ketone group.
- If there is a hydroxyl group attached to the carbonyl carbon, it would be a carboxylic acid.
- If the carbonyl carbon is bonded to an oxygen which is in turn bonded to another carbon, it is an ester.