Question

In the following sequence of reactions, \(CH _{3}- Br \stackrel{ KCN }{\longrightarrow} A \stackrel{ H _{3} O ^{+}}{\longrightarrow} B \stackrel{ LiAlH _{4}}{\longrightarrow} C\), the end product C is

• A. Acetone
• B. Methane
• C. Acetaldehyde
• D. Ethyl alcohol

Answer 1

The Correct Option is D

To determine the final product C in the given sequence of reactions, let's analyze each step:

1. The first reaction is:

   CH _{3}- Br \stackrel{ KCN }{\longrightarrow} A

   In this step, methyl bromide \((CH_3Br)\) reacts with potassium cyanide \((KCN)\) to form methyl cyanide, commonly known as acetonitrile \((CH_3CN)\). The bromine atom is replaced by the cyanide group.

2. The second reaction is:

   A \stackrel{ H _{3} O ^{+}}{\longrightarrow} B

   Hydrolysis of acetonitrile \((CH_3CN)\) in the presence of \(H_3O^+\) (acidic conditions) converts it into acetic acid \((CH_3COOH)\).

3. The third reaction is:

   B \stackrel{ LiAlH _{4}}{\longrightarrow} C

   Reduction of acetic acid \((CH_3COOH)\) using lithium aluminium hydride \((LiAlH_4)\) results in the formation of ethanol \((CH_3CH_2OH)\), also known as ethyl alcohol.

Therefore, the final product C is ethyl alcohol.

Conclusion: The correct answer is Ethyl alcohol.