When ethanol is heated with conc. `H_(2)SO_(4)` at `140^(@)C` (431K), the product obtained is:

Options

A. Ethene
B. Ethyl hydrogen sulphate
C. Ethoxy ethane
D. None of these

Answer

To determine the product obtained when ethanol is heated with concentrated sulfuric acid (H₂SO₄) at 140°C, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are ethanol (C₂H₅OH) and concentrated sulfuric acid (H₂SO₄).

### Step 2: Understand the Reaction Mechanism
When ethanol is heated with concentrated sulfuric acid, the first step involves the dehydration of ethanol. The hydroxyl group (–OH) from ethanol and a hydrogen atom from sulfuric acid are removed, resulting in the formation of ethyl hydrogen sulfate (C₂H₅OSO₃H) and water (H₂O).

### Step 3: Write the Reaction for Dehydration
The dehydration reaction can be represented as:
\[ \text{C}_2\text{H}_5\text{OH} + \text{H}_2\text{SO}_4 \rightarrow \text{C}_2\text{H}_5\text{OSO}_3\text{H} + \text{H}_2\text{O} \]

### Step 4: Further Reaction of Ethyl Hydrogen Sulfate
The ethyl hydrogen sulfate can further react with another molecule of ethanol. In this step, the ethyl hydrogen sulfate reacts with ethanol to produce ethoxyethane (C₂H₅OC₂H₅) and regenerate sulfuric acid.

### Step 5: Write the Reaction for Ether Formation
The etherification reaction can be represented as:
\[ \text{C}_2\text{H}_5\text{OSO}_3\text{H} + \text{C}_2\text{H}_5\text{OH} \rightarrow \text{C}_2\text{H}_5\text{O}\text{C}_2\text{H}_5 + \text{H}_2\text{SO}_4 \]

### Step 6: Identify the Final Product
The final product formed from these reactions is ethoxyethane (C₂H₅OC₂H₅), which is also known as diethyl ether.

### Conclusion
Thus, when ethanol is heated with concentrated sulfuric acid at 140°C, the product obtained is ethoxyethane.

### Final Answer
The product obtained is **ethoxyethane (option C)**.

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