What is the major product formed when ethanol (CH₃CH₂OH) is heated with excess concentrated sulfuric acid at 170°C?
Answer and explanation
Correct answer: A. Ethene (CH₂=CH₂)
- Step 1: Identify the reaction conditions: concentrated H₂SO₄ at high temperature (170°C) acts as a strong dehydrating agent.
- Step 2: At 170°C, intramolecular elimination of water occurs from ethanol to form the alkene ethene (CH₂=CH₂). (At 140°C, intermolecular condensation yields diethyl ether).
Answer
Ethene (CH₂=CH₂).
Why not the others: Diethyl ether is formed at lower temperatures (140°C); ethanoic acid and ethanal are oxidation products, not acid-catalyzed dehydrations.
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