Question

Dehydrohalogenation of an alkyl halide is.

• A. An addition reaction
• B. A substitution reaction
• C. An elimination reaction
• D. An oxidation reaction

Answer 1

Answer: (C)

An elimination reaction

Answer 2

Alkyl halide gives alkene on elimination, reaction takes place in presence of alc. KOH.

$CH_{3}CH_{2}Br + Alc.KOH \rightarrow CH_{2} = CH_{2} + KBr + H_{2}O$

There are two types of elimination reactions.

(1) $E_{1} \rightarrow$ Unimolecular elimination

(2) $E_{2} \rightarrow$ Bimolecular elimination