Question

Which class of organic compounds give effervescence with $NaHC{O}_3$ solution?

• A. Esters
• B. Alcohols
• C. Carboxylic acids
• D. Aldehydes

Answer 1

The correct option is D Aldehydes

Only carboxylic acids react with metal carbonates and produce their corresponding metal salts along with carbon dioxide and water.
The effervescence is due to carbon dioxide.

For example,

${\mathrm{NaHCO}}_3\left(\mathrm{aq}\right)+{\mathrm{CH}}_3\mathrm{COOH}\left(l\right)\to {\mathrm{CH}}_3\mathrm{COONa}\left(\mathrm{aq}\right)+H_{2}O\left(l\right)+{\mathrm{CO}}_2\left(g\right)\mathrm{Sodium}\mathrm{Acetic}\mathrm{acid}\mathrm{Sodium}\mathrm{acetate}\mathrm{water}\mathrm{carbon}\mathrm{dioxide}\mathrm{bicarbonate}$