Question

The reducing agent that reduces acetic acid to ethanol is _______.

• A. ${\mathrm{NaBH}}_4$
• B. ${\mathrm{LiAlH}}_4$
• C. ${\mathrm{Na}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$
• D. All of the above

Answer 1

The correct option is B

${\mathrm{LiAlH}}_4$

Explanation of the correct option:
Option B is correct:

1. Lithium Aluminium Hydride (${\mathrm{LiAlH}}_4$) is a very strong reducing agent.
2. It can reduce Acetic acid (${\mathrm{CH}}_3\mathrm{COOH}$) to Ethanol (${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$) in presence of dilute Sulphuric acid.
3. While other reagents are quite weak and cannot easily reduce Acetic acid to Ethanol.
4. ${\mathrm{LiAlH}}_4$ is the suitable and the strongest reagent for this reduction.

${\mathrm{CH}}_3\mathrm{COOH}+{\mathrm{LiAlH}}_4\to {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}$

Explanation of the incorrect options:
Options A, C, and D are correct:

1. Acetic acid is reduced to Ethanol by Lithium Aluminium Hydride.
2. Hence, these options are incorrect.

Option B is correct.
The reducing agent that reduces acetic acid to ethanol is ${\mathrm{LiAlH}}_4$.