Question

Reaction of aqueous sodium hydroxide on (i) ethyl bromide and (ii) chlorobenzene gives
A. (i) Ethene and (ii) o-chlorophenol
B. (i) Ethyl alcohol and (ii) o-chlorophenol
C. (i) Ethyl alcohol and (ii) phenol
D. (i) Ethyl alcohol and (ii) no reaction

Answer 1

Hint: The reaction between aqueous sodium hydroxide on ethyl bromide and chlorobenzene is a type of nucleophilic substitution reaction. This reaction follows \[{S_N}1\] mechanism.

Complete Step by Step Solution:
\[{S_N}1\]reaction is a type of substitution reaction where \[{S_N}\] stands for nucleophilic substitution and 1 stands for unimolecular which denotes that one reactant determines the rate of reaction.
The reaction usually takes place in two or three steps. In the first step, the leaving group gets removed from the substrate and form a carbocation whereas in the second step nucleophile attack the carbocation and in the third step deprotonation takes place forming the main product. The first step is slow which is the rate-determining step.
The reaction between aqueous sodium hydroxide on ethyl bromide and chlorobenzene follows \[{S_N}1\] mechanism. In the given reaction hydroxide ion is a nucleophile whereas the bromide ion and chloride ion are the leaving groups.
The reaction between aqueous sodium hydroxide and ethyl bromide is shown below.
\[NaOH + {C_2}{H_5}Br \to {C_2}{H_5}OH\]
In the above reaction, sodium hydroxide reacts with ethyl bromide to form ethanol or ethyl alcohol.
The reaction between aqueous sodium hydroxide and chlorobenzene is shown below.
\[NaOH + {C_6}{H_5}Cl \to {C_6}{H_5}OH\]
In the above reaction, sodium hydroxide reacts with chlorobenzene to form phenol.
Therefore, the correct option is C.

Note: It should be noted that deprotonation takes place only when any neutral solvent which acts as a nucleophile is used in the reaction. Here, sodium hydroxide is not a neutral solvent so the reaction takes place in two steps. In the first step, the halogen group is removed to form a stable carbocation and in the second step nucleophiles attack the carbocation from both sides to form the product.