Question

The treatment of alkyl chloride with aqueous koh leads to the formation of alcohol but in the presence of alcoholic koh, alkene is the major product,

Answer 1

In aqueous KOH , OH- is easily formed an Tus it attacks on alkyl chloride to give alcohol .While KOH in alcoholic solution does not produce OH- so alkene is the major product.

Answer 2

Hey !!

In aqueous solution, KOH is almost completely ionised to give OH⁻ ions which being a strong nucleophile brings about a substitution reaction on alkyl halides to form alcohols. In the aqueous solution, OH⁻ ions are highly hydrated. This reduces the basic character of OH⁻ ions which fail to abstract a hydrogen from the β-carbon of the alkyl chloride to form an alkene.

         On the other hand, an alcoholic solution of KOH contains alkoxide (OR⁻) ions which being a much stronger base than OH⁻ ions preferentially eliminates a molecule of HCl from an alkyl chloride to form alkenes.

Hope it helps you !!