Which prefix corresponds to the 3-carbon alkyl group?

Which prefix corresponds to the 3-carbon alkyl group?

• A. Ethyl
• B. Chloro
• C. Propyl
• D. Methyl

Answer: (C)

In organic nomenclature, alkyl prefixes tell you how many carbon atoms are in the substituent. A three-carbon alkyl group is called propyl. That means any substituent with three carbons attached to the main chain is described as propyl (such as n-propyl or isopropyl). The other terms here correspond to different ideas: methyl denotes one carbon, ethyl denotes two carbons, and chloro is not an alkyl group at all—it names a chlorine substituent. So for a 3-carbon alkyl group, the correct prefix is propyl.

In organic nomenclature, alkyl prefixes tell you how many carbon atoms are in the substituent. A three-carbon alkyl group is called propyl. That means any substituent with three carbons attached to the main chain is described as propyl (such as n-propyl or isopropyl). The other terms here correspond to different ideas: methyl denotes one carbon, ethyl denotes two carbons, and chloro is not an alkyl group at all—it names a chlorine substituent. So for a 3-carbon alkyl group, the correct prefix is propyl.