Question

The compound formed in the following reaction is
\(\text{CH}_3-\text{CH}_2-\text{OH} \xrightarrow[\text{Conc. H}_2\text{SO}_4]{170^\circ\text{C}} \text{?}\)

• A. \(\text{CH}_3\text{CHO}\)
• B. \(\text{CH}_3\text{-CH}_3\)
• C. \(\text{CH}_3\text{COOH}\)
• D. \(\text{CH}_2=\text{CH}_2\)

Answer 1

The Correct Option is D

To solve the problem, we need to identify the compound formed when ethanol (CH₃CH₂OH) is heated with concentrated sulfuric acid (H₂SO₄) at 170°C.

1. Understanding the Reaction Conditions:
When alcohols are heated with concentrated sulfuric acid at high temperatures (~170°C), a dehydration reaction occurs, which removes a water molecule and forms an alkene.

2. Reaction Mechanism:
CH₃CH₂OH (ethanol) → CH₂=CH₂ (ethene) + H₂O
This is an example of an elimination reaction (E1 mechanism), where ethanol loses a water molecule to form ethene.

3. Eliminate Incorrect Options:
- (1) CH₃CHO → Ethanal (formed by mild oxidation, not dehydration)
- (2) CH₃–CH₃ → Ethane (not formed by dehydration)
- (3) CH₃COOH → Acetic acid (formed by complete oxidation)
- (4) CH₂=CH₂ → Ethene (correct product of dehydration of ethanol)

Final Answer:
The compound formed is CH₂=CH₂ (ethene).