The correct option is Ethene.
Explanation
The reaction involves the acidic dehydration of alcohols. When alcohols are heated with a protic acid such as concentrated sulphuric acid ($H_2SO_4$) or phosphoric acid ($H_3PO_4$), they lose a water molecule to form alkenes or ethers depending on the reaction conditions.
Detailed Analysis:
- Dehydrating Agent: Concentrated sulphuric acid acts as a strong dehydrating agent.
- Temperature Dependence: The product of the reaction between ethanol and sulphuric acid is strictly dependent on temperature.
- At 443 K ($170^\circ$C): Ethanol undergoes intramolecular dehydration. A water molecule is removed from a single molecule of ethanol, resulting in the formation of Ethene ($C_2H_4$).
- Reaction:
$CH_3CH_2OH \xrightarrow[\text{443 K}]{\text{Conc. } H_2SO_4} CH_2=CH_2 + H_2O$
- Comparison (for clarity): At a lower temperature of 413 K ($140^\circ$C), intermolecular dehydration occurs, leading to the formation of Ethoxyethane (Diethyl ether). Since the question specifies 443 K, the product is Ethene.
Key Takeaway:
The dehydration of ethanol with concentrated sulphuric acid yields ethene at 443 K via elimination, while it yields ether at 413 K via substitution.