Organic nomenclature, homologous series and functional groups
≈ 50 minOrganic nomenclature, homologous series and functional groups
Organic chemistry classifies carbon compounds by the functional group that controls many characteristic reactions. A homologous series has the same functional group and general formula, with successive members differing by CH₂. Name a simple molecule by finding the longest carbon chain, numbering from the end nearest the functional group or substituent, locating branches and selecting the correct suffix. Alkanes use -ane, alkenes -ene, alcohols -ol, haloalkanes use a halo prefix, carboxylic acids use -oic acid and esters use alkyl alkanoate. A name must match a structural formula; do not name from atom count alone.
Work it through
CH₃CH₂CH₂OH has a three-carbon parent chain and an alcohol group on carbon 1, so the name is propan-1-ol. Numbering from the OH end gives the lowest location number. If the OH were on carbon 2, the name would be propan-2-ol. The hyphens and numbers communicate structure, not punctuation decoration.
Mastery target
Classify a molecule by functional group and produce or interpret a systematic name with the correct parent chain, numbering and suffix.
What is the correct name for CH₃CH₂CH₂OH?
Name the key chemistry term from Organic nomenclature, homologous series and functional groups that best fits the explanation and visual model.
Which feature defines a homologous series?
Which statement corrects a common misunderstanding in Organic nomenclature, homologous series and functional groups?