Ethylidene chloride is a
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → geminal dihalide.
Dihalogen derivatives of alkanes are named by where the two halogen atoms sit:
Geminal (gem) dihalides: both halogens on the same carbon. Their common names end in “-idene halide”, e.g. ethylidene chloride, \( \ce{CH3CHCl2} \).
Vicinal (vic) dihalides: halogens on adjacent carbons. Their common names end in “-ylene dihalide”, e.g. ethylene dichloride, \( \ce{ClCH2CH2Cl} \).
Two other classes depend on the position of the halogen with respect to a C=C bond:
Vinylic halides: halogen on an sp2 carbon of the C=C bond, e.g. \( \ce{CH2=CHCl} \).
Allylic halides: halogen on the sp3 carbon next to the C=C bond, e.g. \( \ce{CH2=CH-CH2Cl} \).
Ethylidene chloride is \( \ce{CH3-CHCl2} \) (1,1-dichloroethane). Both chlorine atoms are on the same carbon, so it is a geminal dihalide.
NCERT (2026-27 edition):
Nomenclature – …
