Question

Which of the following is boiled with ethyl chloride to form ethyl alcohol
A. Alcoholic KOH
B. Aqueous KOH
C. \[{H_2}O\]
D. \[{H_2}{O_2}\]

Answer 1

Hint: In the given reaction nucleophilic substitution takes place. In a nucleophilic substitution reaction, the nucleophile replaces the leaving group to form the compound.

Complete Step by Step Solution:
The aqueous solution of KOH is a solution formed by dissolving solid potassium hydroxide in water. It acts as a strong base which gives both nucleophilic substitution reaction and elimination reaction.

A nucleophilic substitution reaction is a type of reaction where a leaving group is removed from the reactant and the nucleophile attacks the alpha carbon atom by eliminating the byproduct and forming the main product i.e, alcohol.

The elimination reaction is a type of reaction where two or more adjacent atoms are removed to form the product. When ethyl chloride is boiled with aqueous potassium hydroxide, it forms ethyl alcohol as the main product. The reaction is shown below:
\[{C_2}{H_5}Cl + aq.KOH \to {C_2}{H_5}OH + HCl\]

In the above reaction, one mole of ethyl chloride reacts with one mole of an aqueous solution of potassium hydroxide to form one mole of ethanol and one mole of hydrochloric acid.

Here, the chloride group is a leaving group and hydroxide acts as a nucleophile which will attack the alpha carbon from the back and break the bond by eliminating the product.
Therefore, the correct option is B.

Note: It should be noted that when ethyl chloride is treated with an alcoholic solution of potassium hydroxide, an alkene is formed as the main product and the reaction is called dehydrohalogenation reaction.