Alcoholic solution of KOH is used for ,

Options

A. Dehydration
B. Dehydrogenation
C. Dehydrohalogenation
D. Dehalogenation

Answer

C

Explanation

`CH_(3)-CH_(2)-Br + underset("alcoholic")(KOH) overset("dehydrohalgenation")rarrCH_2=CH_2+KBr + H_2O`
In alcoholic KOH alkoxide ions `(RO^-)` are present which is a strong base. They abstract proton from `beta`- carbon of alkyl halide and favours elimination reaction.
`underset("Alcohol")(ROH) + KOH rarr underset("Potassium")(ROK)+underset("alkoxide")(H_2O)`
`ROK rarr underset("Alkoxide ion")(RO^- )+K^(+)`
`RO^(-) + H-overset(beta)(CH_2)-overset(alpha)(CH_2)-Br rarr ROH + CH_(2) = CH_(2) + KBr`