The sodium bicarbonate () test is commonly used to distinguish strongly acidic compounds from weakly — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

For a compound to decompose $NaHCO_3$ and release $CO_2$, its acidic strength must be greater than that of carbonic acid ($H_2CO_3$, $pKa \approx 6.4$). Picric acid, benzenesulphonic acid, and squaric acid are highly acidic and react readily. However, 2-nitrophenol ($pKa \approx 7.2$) is a weaker acid than carbonic acid and thus fails the bicarbonate test.