Question

Which one of the following does not liberate hydrogen on reaction with sodium metal?

• A. $C_2{H}_2$
• B. $C_2{H}_{5}OH$
• C. $C{H}_{3}COOH$
• D. $C{H}_{3}CHO$

Answer 1

Answer: (D)

$C{H}_{3}CHO$

Aldehydic group does not have any acidic hydrogen atom which can be liberated as hydrogen gas on reaction with sodium metal whereas acetylene, ethanol and ethanoic acid, all have acidic hydrogens.

The reaction between sodium metal and a compound containing acidic hydrogen is as follows:

$R-H+Na\to R^{-}N{a}^{+}+H_2$

Therefore, $C{H}_{3}CHO$ does not liberate hydrogen on reaction with sodium metal.

Option D is correct.