Question map
In which of the following, functional group isomerism is not possible?
Explanation
Functional group isomerism occurs when compounds share the same molecular formula but possess different functional groups. Alcohols (R-OH) exhibit functional isomerism with ethers (R-O-R) [1]. Aldehydes (R-CHO) are functional isomers of ketones (R-CO-R) [1]. Cyanides (R-CN), also known as nitriles, exhibit functional isomerism with isocyanides (R-NC) [2]. However, alkyl halides (R-X, where X is a halogen) do not have a corresponding functional group isomer with the same molecular formula. While alkyl halides can exhibit chain isomerism or position isomerism (such as 1-chloropropane and 2-chloropropane), they lack a distinct functional group counterpart [1]. Therefore, functional group isomerism is not possible for alkyl halides. This distinction is fundamental in organic chemistry nomenclature and structural analysis [1].
Sources
- [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Table 4.4 Nomenclature of organic compounds > p. 68
- [2] https://pmc.ncbi.nlm.nih.gov/articles/PMC6856803/