Chemistry Alcohols & Phenols DUHS 2023
PMDC Verified Question 30 of 95
Which of the following reactions can be used for the conversion of ethyl alcohol into acetaldehyde?
A
Polymerization
B
Dehydrogenation
C
Esterification
D
Reduction
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Dehydrogenation
Concept:

Converting an alcohol to an aldehyde involves the removal of two hydrogen atoms to form a C=O double bond. This can be viewed conceptually and practically as the removal of hydrogen.

Formula:

$$ \text{CH}_3\text{CH}_2\text{OH} \xrightarrow[300^{\circ}\text{C}]{\text{Cu}} \text{CH}_3\text{CHO} + \text{H}_2 $$

Solution:

  • Ethyl alcohol can be converted to acetaldehyde by passing its vapors over heated copper at 300°C.


  • During this process, a molecule of hydrogen gas (\(\text{H}_2\)) is eliminated.


  • The chemical removal of hydrogen is formally termed dehydrogenation (which is a subtype of oxidation).


Why other options are incorrect:

Reduction would add hydrogen (impossible here since the carbon is already saturated). Esterification creates an ester, not an aldehyde. Polymerization chains molecules together.

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