Identify the product 'Z' in the following sequence of reactions.
`CH_(3)CNoverset(Na+C_(2)H_(5)OH)rarr Xoverset(HNO_(2))underset(H_(2)O)rarrYoverset(K_(2)Cr_(2)O_(7))underset(H_(2)SO_(4))rarr Z`

Options

A. `CH_(3)CHO`
B. `CH_(3)CONH_(2)`
C. `CH_(3)COOH`
D. `CH_(3)CH_(2)NHOH`

Answer

To identify the product 'Z' in the given sequence of reactions, we will break down each step of the reaction process.

### Step-by-Step Solution:

1. **Starting Material: CH₃CN (Acetonitrile)**
- The first step involves the reaction of acetonitrile (CH₃CN) with sodium (Na) and ethanol (C₂H₅OH). This is known as the Mendes rearrangement.
- **Reaction**:
\[ \text{CH}_3\text{CN} + \text{Na} + \text{C}_2\text{H}_5\text{OH} \rightarrow \text{X} \]
- In this reaction, acetonitrile is converted to a primary amine, specifically ethylamine (CH₃CH₂NH₂).
- **Product X**:
\[ \text{X} = \text{CH}_3\text{CH}_2\text{NH}_2 \text{ (ethylamine)} \]

2. **Reaction of X with HNO₂ and H₂O**
- The next step involves treating the primary amine (X) with nitrous acid (HNO₂) in the presence of water.
- **Reaction**:
\[ \text{X} + \text{HNO}_2 + \text{H}_2\text{O} \rightarrow \text{Y} \]
- When ethylamine reacts with nitrous acid, it forms ethanol (CH₃CH₂OH) and nitrogen gas (N₂) is released.
- **Product Y**:
\[ \text{Y} = \text{CH}_3\text{CH}_2\text{OH} \text{ (ethanol)} \]

3. **Oxidation of Y with K₂Cr₂O₇ and H₂SO₄**
- The final step involves the oxidation of ethanol (Y) using potassium dichromate (K₂Cr₂O₇) in the presence of sulfuric acid (H₂SO₄).
- **Reaction**:
\[ \text{Y} + \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 \rightarrow \text{Z} \]
- Ethanol is oxidized to acetic acid (CH₃COOH).
- **Product Z**:
\[ \text{Z} = \text{CH}_3\text{COOH} \text{ (acetic acid)} \]

### Final Answer:
The product 'Z' is **CH₃COOH (acetic acid)**.

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