Identification of aromatic amine functional group

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

Preliminary test:

(i) Physical State	Liquid
(ii) Colour	Red brown
(iii) Odour	Pungent like petrol
(iv) Solubility in water	Sparingly 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 red litmus paper	Red litmus turns blue	Organic substance is basic in nature.
3	Flame Test: Touch the organic substance on copper wire and ignite it	Sooty flame is produced	Compound is aromatic
4	Functional Group Analysis:       (i) Organic substance + conc. HCl + NaNO2 solution + ice cooled + β-naphthol solution (ii) KOH pallets + ethanol + heat + CHCl3 + Organic substance + heat	Red-orange colour is produced An unpleasant odour of carbylamine produced	Ar-NH2 group is present Ar-NH2 group is confirmed

                             

Result: The given organic compound contains the aromatic amine functional group.

Identification of ketonic functional group

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

Preliminary test:

(i) Physical State	Liquid
(ii) Colour	Colourless
(iii) Odour	Like nail polish remover
(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 & red litmus paper	No reaction	Organic substance is neutral in nature.
3	Flame Test: Touch the organic substance on copper wire and ignite it	Non-sooty flame is produced	Compound is aliphatic
4	Functional Group Analysis:       (i) Organic substance + 2,4-dinitrophenylhydrazine (ii) Organic substance + Tollen reagent + heat (iii) Organic substance + m-dinitrobenzene + dil.NaOH (iv) organic compound + sodium nitroprusside solution + NaOH solution	Yellow ppt produced Violet colour produced Red ppt is produced Red-violet solution is produced	Carbonyl group is present  Aldehyde group absent  Ketonic group is present Ketonic group is confirmed

                             

Result: The given organic compound contains the Ketonic functional group.

Identification of aldehyde functional group

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

Preliminary test:

(i) Physical State	Liquid
(ii) Colour	Colourless
(iii) Odour	Pungent
(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 & red litmus paper	No reaction	Organic substance is neutral in nature.
3	Flame Test: Touch the organic substance on copper wire and ignite it	Non-sooty flame is produced	Compound is aliphatic
4	Functional Group Analysis:        (i) Organic substance +             2,4-dinitrophenylhydrazine (ii) Organic substance + Tollen reagent + heat (iii) Organic substance + Fehling solution + heat (iv) organic compound + Schiff’s reagent	Yellow ppt produced Silver mirror is produced Red ppt is produced Pink solution is produced	Carbonyl group is present  Aldehyde group may be present  Aldehyde group is present Aldehyde group is confirmed

                             

Result: The given organic compound contains the Aldehyde functional group.

Identification of phenolic functional group

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

Preliminary test:

(i) Physical State	Solid
(ii) Colour	Light pink
(iii) Odour	Like lifebuoy soap (Phenolic)
(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	Litmus paper turns red	Organic substance is acidic in nature. It may be carboxylic or phenolic group.
3	Flame Test: Touch the organic substance on copper wire and ignite it	Organic substance shows sooty flame	Compound is aromatic
4	Functional Group Analysis:       (i) Organic substance + NaHCO3 + heat   (ii) FERRIC CHLORIDE TEST: Aq. Solution of organic substance + 1-2 mL of neutral FeCl3 solution (iii) LIEBERMANN NITROSO TEST: a.     Organic substance + solid NaNO2 + dil H2SO4 + heat b.     above solution + H2O c.      above solution + NaOH solution	No reaction Colour of solution change to green Green blue solution is produced Colour of solution change green to red Colour of solution changed to blue-green	Carboxylic acid group is absent Phenolic group is present Phenolic group is present

                              

Result: The given organic compound contains the Phenolic functional group.