Question

Which product is not obtained when \( \mathrm{CH_3CH_2OH} \) reacts with \( \mathrm{H_2SO_4} \)?

• A. \( \mathrm{CH_2{=}CH_2} \)
• B. \( \mathrm{CH{\equiv}CH} \)
• C. \( \mathrm{C_2H_5OC_2H_5} \)
• D. \( \mathrm{C_2H_5HSO_4} \)

Hint:

For ethanol with concentrated \( \mathrm{H_2SO_4} \), remember the temperature effect: ethyl hydrogen sulphate at low temperature, diethyl ether at about \( 413 \, \mathrm{K} \), and ethene at about \( 443 \, \mathrm{K} \). Ethyne is not formed in this reaction.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Ethanol reacts with sulfuric acid ($H_2SO_4$) in different ways depending on the temperature and concentration.
Step 2: Formula Application:
1. At 443 K: Dehydration to Ethene ($CH_2=CH_2$). 2. At 413 K: Dehydration to Ethoxyethane ($C_2H_5OC_2H_5$). 3. Low Temp: Formation of Ethyl hydrogen sulfate ($C_2H_5HSO_4$).
Step 3: Explanation:
Sulfuric acid can remove water to create single or double bonds, but it cannot perform the triple dehydration required to create Acetylene ($CH \equiv CH$) from a saturated alcohol like ethanol.
Step 4: Final Answer:
Acetylene ($CH \equiv CH$) is not obtained.