Sodium bicarbonate test is the best method to experimentally distinguish carboxylic acid from alcohol because even phenol does not respond to this test. In this test, carboxylic acid reacts with sodium bicarbonate to form sodium acetate and a brisk effervescence of CO2.
This effervescence is what indicates the carboxylic acid.
RCOOH + NaHCO3 → RCOONa + H2O + CO2
NOTE: Sodium bicarbonate test is also known as sodium hydrogen-carbonate test.
