Question

An aryl carboxylic acid on treatment with sodium hydrogen carbonate liberates a gaseous molecule. Identify the gas molecule liberated.

• A. H2
• B. CO2
• C. CO
• D. O2

Hint:

Carboxylic acids give brisk effervescence with NaHCO3} due to CO2} gas evolution.

Answer 1

The Correct Option is B

Carboxylic acids react with NaHCO3} to liberate carbon dioxide gas:
Ar–COOH + NaHCO3} → Ar–COONa + H2}O + CO2}↑
Effervescence of CO2} is a test for carboxylic acids.