Question
Question: Name the functional groups present in \( C{H_3}CHO \) and \( C{H_3}COC{H_3} \) ....
Name the functional groups present in CH3CHO and CH3COCH3 .
Solution
The functional groups present in organic compounds can be identified by looking at the IUPAC names of the compounds or drawing the structure of the compounds. Each functional group involves carbon as a specific formula and bond connectivity that is characteristic in nature.
Complete answer:
Functional groups are a special group of molecular species that are usually attached to hydrocarbon parent chains. The presence of these functional groups in the hydrocarbon chains enhances its reactivity and selectivity towards particular reactions.
One such category of functional groups is the carbonyl functional group that involves two types of groups: the aldehyde group and the ketone group.
Aldehyde group contains a carbon atom double bonded to an oxygen atom and one of its valencies is occupied by a hydrogen atom and therefore they are always attached to the terminal positions and can never be placed in between two carbon atoms.
The ketone group simply contains a carbon atom double bonded to an oxygen atom and both of its valencies are free to connect to the carbon atoms of chains. Hence, ketones occupy the interior positions and not the terminal positions.
The formula for aldehyde is −CHO and that of ketone is −CO− .
⇒ Thus, the compound CH3CHO contains an aldehyde functional group and the compound CH3COCH3 contains a ketone functional group.
Note:
Even though aldehyde and ketone functional groups are collectively called carbonyl groups, there are chemical tests like Tollen’s test that can be used to distinguish between an aldehyde and a ketone. Aldehydes show Tollen’s test but ketones do not.