The presence of carboxyl group in a compound is detected by sodium bicarbonate test. A pinch of given compound is added to strong solution of `NaHCO_(3)`. The evolution of `CO_(2)` gas accompanied by brisk effervescence shows the presence of carboxyl group.
`underset("Carboxylic acid")underset()(RCOOH)+NaHCO_(3)rarrunderset("Sod. salt")underset()(RCOONa)+H_(2)O+CO_(2)`
