Question

Which of the following compounds is least likely to give effervescence of CO$_2$ in presence of aq. NaHCO$_3$?

• A.
• B.
• C.
• D.

Hint:

In reactions with NaHCO\(_3\), look for acidic functional groups (like -COOH or -OH) that readily react to release CO\(_2\). Nitrogenous compounds without strong acidic groups generally do not react.

Answer 1

The Correct Option is D

In this question, we are determining which compound is least likely to produce effervescence of CO\(_2\) when reacted with aqueous NaHCO\(_3\). Effervescence occurs when an acid reacts with NaHCO\(_3\), producing CO\(_2\). 
Compound (1) contains a hydroxyl group (-OH) and nitro groups (-NO\(_2\)) which will likely result in an acidic environment and cause effervescence with NaHCO\(_3\). 
Compound (2) contains a carboxyl group (-COOH), a strong acid, which will react with NaHCO\(_3\) and release CO\(_2\). 
Compound (3) contains an amine group (-NH\(_3\)), which is basic and does not typically react with NaHCO\(_3\) to produce CO\(_2\). 
Compound (4) contains a nitro group (-NO\(_2\)) but lacks a strongly acidic functional group that would promote CO\(_2\) production. 
Thus, it is the least likely to produce CO\(_2\) effervescence in the presence of NaHCO\(_3\). 
Therefore, the compound least likely to give effervescence of CO\(_2\) is compound (4).