Identification of Carboxylic acid functional group

Aim: To identify the functional group present in an organic compound.

Preliminary test:

(i) Physical State	Solid
(ii) Colour	Colourless
(iii) Odour	Vinegar like
(iv) Solubility in water	Soluble

Chemical Test:

S.No.	Experiment	Observation	Inference
1	Test for Unsaturation Dissolve 0.2 mL of organic compound in 2 mL CCl4. Then added bromine water dropwise.	Brown colour of bromine not discharged	Unsaturation is not present
2	Litmus Test: Put a drop of an aqueous solution of the original substance on a piece of blue litmus paper	Blue litmus paper turns to red	Organic substance is acidic in nature. It may be a carboxylic or phenolic group.
3	Flame Test: Touch the organic substance on copper wire and ignite it	Organic substance shows non-sooty flame	Compound is aliphatic
4	Functional Group Analysis: (a)    Aq. Solution of organic compound + NaHCO3 solution (b)   Ester Test: Organic substance + conc. H2SO4 + C2H5OH + Heat	CO2 gas is evolved with a brisk effervescence that turns lime water milky Fruity smell is evolved	Carboxylic group may be present. Carboxylic group is present.

Result: The given organic compound contains the carboxylic acid functional (-COOH) group.