Select the correct product when ethanol is heated at 443 K with excess concentrated sulphuric acid.

Correct option is B

Explanation:

• When ethanol (CH₃CH₂OH) is heated at 443 K (170°C) with excess concentrated sulphuric acid (H₂SO₄), it undergoes a dehydration reaction. In this process, a water molecule (H₂O) is removed from ethanol, resulting in the formation of ethene (CH₂=CH₂).
• The reaction mechanism involves the formation of a carbocation intermediate, which then eliminates a water molecule, leading to the formation of the alkene.

The reaction can be written as:

• CH₃COOH (acetic acid) is not formed when ethanol undergoes dehydration in the presence of concentrated sulfuric acid at 443 K.
• Acetic acid is typically produced via the oxidation of ethanol (e.g., using oxygen or potassium dichromate), not by dehydration.
• The dehydration process with sulfuric acid at this temperature does not produce acetic acid. Instead, it produces ethene (CH₂=CH₂), as I mentioned earlier.

• CH₃—CH₃ represents ethane, which is a saturated hydrocarbon (alkane).
• Ethane cannot be formed from ethanol via dehydration under these conditions.
• For ethane to be produced, a reduction (hydrogenation) reaction would be needed, not a dehydration reaction. Ethanol would have to undergo a hydrogenation process, which typically requires a catalyst like nickel (Ni) and hydrogen gas (H₂) at high pressure, not concentrated sulfuric acid.
• Therefore, ethane is not a product of heating ethanol with sulfuric acid at 443 K.

• CH₄ (methane) is a simple alkane and is not produced in this reaction.
• The dehydration of ethanol with sulfuric acid results in ethene (CH₂=CH₂), not methane.

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