The end product (B) in the following sequence of reactions is `CH_(3)Cl overset(KCN)rarr A overset(H_(2)O //H^(+))rarr B`

Options

A. A cyanide
B. A carboxylic acid
C. an amine
D. an arene

Answer

To determine the end product (B) in the given sequence of reactions, we will follow the steps outlined in the problem.

### Step 1: Identify the starting material
The starting material is methyl chloride (CH₃Cl).

### Step 2: Nucleophilic substitution reaction
Methyl chloride (CH₃Cl) reacts with potassium cyanide (KCN). In this reaction, the cyanide ion (CN⁻) acts as a nucleophile and attacks the electron-deficient carbon atom in methyl chloride. The chlorine atom (Cl⁻) is displaced, resulting in the formation of methyl cyanide (CH₃CN).

**Reaction:**
\[ \text{CH}_3\text{Cl} + \text{KCN} \rightarrow \text{CH}_3\text{CN} + \text{KCl} \]

### Step 3: Hydrolysis of methyl cyanide
Next, methyl cyanide (CH₃CN) undergoes hydrolysis in the presence of water (H₂O) and an acid (H⁺). During this reaction, the cyanide group (–CN) is converted into an amide (–C(=O)NH₂) intermediate.

**Reaction:**
\[ \text{CH}_3\text{CN} + \text{H}_2\text{O} \xrightarrow{H^+} \text{CH}_3\text{C(=O)NH}_2 \]

### Step 4: Further hydrolysis to form carboxylic acid
The amide (CH₃C(=O)NH₂) is then further hydrolyzed by water (H₂O) in the presence of an acid (H⁺) to produce acetic acid (CH₃C(=O)OH) and ammonia (NH₃).

**Reaction:**
\[ \text{CH}_3\text{C(=O)NH}_2 + \text{H}_2\text{O} \rightarrow \text{CH}_3\text{C(=O)OH} + \text{NH}_3 \]

### Final Product
The final product (B) is acetic acid (CH₃C(=O)OH).

### Summary of the Reaction Sequence
1. **Starting Material:** CH₃Cl (Methyl Chloride)
2. **Intermediate (A):** CH₃CN (Methyl Cyanide)
3. **End Product (B):** CH₃C(=O)OH (Acetic Acid)