Aniline qualitative analysis

Qualitative Analysis of Aniline

1. Qualitative Analysis of an Unknown Sample. Mrs Chanda Ranjan Department of Pharmaceutical Chemistry The Oxford College of Pharmacy, Bangalore

2. Learning outcome: Understand how to conduct – 1. P reliminary investigation 2. Solubility Analysis 3. Elemental detection 4. Functional group Analysis 5. Confirmatory test of any unknown compound in the lab. Learning Outcome

3. Experiment Observation Inference Physical appearance and Color Odor Solubility Characteristics Take about 0.1 g of solid (0.5 ml of liquid) each in four separate test tubes and add 3 ml each of cold and hot water b) 5% HCL   c) 5% NaOH. d) Ether   Fishy Light yellow colored liquid @ Chanda Ranjan 4 Insoluble in Water Insoluble in 5% NaOH Soluble in 5% HCl Soluble in Ether Preliminary Investigation Alcohol , ketone , aldehyde, ester, phenol, amines may be present. Amine

4. According to the solubility of the organic compound there are 7 groups Group II Group I Group IV Group III Group V Group VII Group VI Soluble in water and ether Soluble in water and insoluble in ether Insoluble in water , soluble in ether and readily soluble in Bases (5% NaOH) Soluble in ether , insoluble in water, but soluble in diluted acid (5% HCl) N and S is absent Some Phenols Alcohols Aldehydes Ketones and Acids having Low MW (upto 5 to 6 carbon atoms Sugars Glucose Urea Thiourea Acids, Phenols Imides Amines Aromatic-N- heterocycles Unsaturated hydrocarbons Aldehydes, ketones, esters, ethers anhydrides, acyl halides Hydrocarbons Halogen Hydrocarbons Cyclic Paraffin Amides Nitro Compounds, Nitriles Soluble only in conc H2SO4 Insoluble only in conc H2SO4 Contains N and S And all the solubility test fails Solubility Analysis

5. 6 Preliminary Investigation Experiment Observation Inference Physical appearance and Color Carbohydrate, acid , phenol, amine , higher hydrocarbon may be present Odor Phenol, cresol. Solubility Characteristics Take about 0.1 g of solid (0.5 ml of liquid) each in four separate test tubes and add 3 ml each of cold and hot water b) 5% HCL   c) 5% NaOH. d) Ether Insoluble in Water Insoluble in 5% NaOH Soluble in 5% HCl S oluble in Ether Compound belongs to Group IV That comprises: Amines, Hydrazines

6. Experiment Observation Inference Test for acidic or basic nature   Dissolve about 0.5 ml of liquid in water and place one drop of the solution on blue and red litmus each. Dissolve 0.5 gm of the given solid into 2ml of 5% NaHCO 3 solution Red Litmus turned blue Compound is basic in nature, Action of 5 % NaHCO 3 Insoluble with no characteristic changes. Compound can be Phenols or amines Red Litmus Paper Preliminary Investigation

7. Test for aromatic or aliphatic nature Take a small quantity of the given organic compound on a nickel spatula and ignite (heat strongly) Add 1 ml of conc HNO 3 and 1 ml of conc . H 2 SO 4 to a small quantity of the substance . Heat well and cool. Pour into a beaker of water . (NITRATION TEST)     1 ml of conc HNO 3 1 ml of conc . H2SO 4 Water Yellow color is observed Sooty flame Presence of aromatic compound 7/16/2020 @Chanda Ranjan 8 Presence of aromatic compound Pour Preliminary Investigation

8. Test for saturation or unsaturation A) Bromine water test Add 2 or 3 drops of saturated bromine water to the substance and shake well.   B) Baeyer’s Reagent test Add 1 ml of water and 2 drops of Baeyer's reagent (alkaline potassium permanganate) to a small quantity of the substance.     2 drops of Br 2 water shaken The color of bromine is not discharged 2 drops of Baeyer's reagent shaken Pink color is not discharged Compound is saturated Compound is saturated 9 Preliminary Investigation

9. Experiment Observation Inference Test with neutral FeCl 3 solution  Add 1 gm of neutral ferric chloride solution to a small quantity of the compound.     1ml of Ferric Chloride No Purple color formed Phenolic group is absent Preliminary Investigation

10. Procedure for the preparation of sodium fusion extract or Lassaigne's Extract. A small piece of dry sodium  in a fusion tube is taken. Heat the tube slightly on a Bunsen burner so that the sodium melts and looks red hot. Add a pinch of the sample. Heat it slowly to start with so that the compound reacts with sodium metal and continue heating till it becomes red hot. Plunge the red hot tube into a china dish containing distilled water. Crush the contents with a glass rod and heat to boiling point and concentrate the solution. Filter it with the help of funnel and filter paper. The filtrate is called Lassaigne's Extract. Elemental Analysis

11. Detection of Elements Preparation of Sodium fusion extracts tests or lassaigne's tests 7/16/2020 @Chanda Ranjan 12 Elemental Analysis

12. Experiment Observation Inference Test for nitrogen   To 1 ml of the sodium fusion extract add 1 ml of ferrous sulphate solution. Add about 1 ml of dilute sulphuric acid.   b) Test for Sulphur   To 1 ml of the sodium fusion extract add 3 drops of freshly prepared sodium nitroprusside solution. To another portion of the extract add 4 drops of lead acetate solution.   c) Test for Halogen To another portion of the extract add dilute nitric acid to acidify and silver nitrate solution (1ml)     d) Test for Nitrogen and Sulphur together Take a small portion of the sodium fusion extract and add 2 ml of dil HCl and 1ml of FeCl3 solution . Shake well.     1 ml of ferrous sulphate solution shake D ark greenish grey ppt of ferrous hydroxide is formed 1 ml of dilute sulphuric acid. Formation of Prussian blue ppt Nitrogen is present 7/16/2020 @Chanda Ranjan 13 Elemental Analysis

13. Experiment Observation Inference Test for nitrogen   To 1 ml of the sodium fusion extract add 1 ml of ferrous sulphate solution. Add about 1 ml of dilute sulphuric acid.   b) Test for Sulphur 1. To 1 ml of the sodium fusion extract add 3 drops of freshly prepared sodium nitroprusside solution 2. To the sample add 1 ml of dilute acetic acid and few drops of lead acetate solution c) Test for Halogen To another portion of the extract add dilute nitric acid to acidify and silver nitrate solution (1ml)    d) Test for Nitrogen and Sulphur together Take a small portion of the sodium fusion extract and add 2 ml of dil HCl and 1ml of FeCl3 solution . Shake well.     shake 3 drops of freshly prepared sodium nitroprusside solution No appearance of brilliant purple color 1 ml of dil acetic acid + Few drops of lead acetate No appearance of black ppt Sulphur is Absent Elemental Analysis

14. Experiment Observation Inference Test for nitrogen   To 1 ml of the sodium fusion extract add 1 ml of ferrous sulphate solution. Add about 1 ml of dilute sulphuric acid.   b) Test for Sulphur   To 1 ml of the sodium fusion extract add 3 drops of freshly prepared sodium nitroprusside solution. To another portion of the extract add 4 drops of lead acetate solution.   c) Test for Halogen To another portion of the extract add dilute nitric acid to acidify and silver nitrate solution (1ml)     d) Test for Nitrogen and Sulphur together Take a small portion of the sodium fusion extract and add 2 ml of dil HCl and 1ml of FeCl3 solution . Shake well.     shake 1ml of dil nitric acid + 1ml of silver nitrate solution No white or yellow ppt formed Absence of Halogens 7/16/2020 @Chanda Ranjan 15 Elemental Analysis

15. Experiment Observation Inference Test for nitrogen   To 1 ml of the sodium fusion extract add 1 ml of ferrous sulphate solution. Add about 1 ml of dilute sulphuric acid. b)Test for Sulphur To 1 ml of the sodium fusion extract add 3 drops of freshly prepared sodium nitroprusside solution. To another portion of the extract add 4 drops of lead acetate solution. c) Test for Halogen To another portion of the extract add dilute nitric acid to acidify and silver nitrate solution (1ml)     d) Test for Nitrogen and Sulphur together Take a small portion of the sodium fusion extract and add 2 ml of dil HCl and 1ml of FeCl3 solution . Shake well.     shake 2 ml of dil HCl + 1ml of FeCl 3 solution No blood red color formation Nitrogen and sulphur both are absent 7/16/2020 @Chanda Ranjan 16 Elemental Analysis

16. Conclusion drawn: A fter the Preliminary investigation, elemental analysis and solubility analysis. The compound showed positive saturated aromatic behavior and is basic in nature. The compound has presence of special elements nitrogen but shows negative result to sulphur and halogens. The compound is insoluble in water, 5% NaOH, but soluble in 5% HCl and ether which shows that the compound belongs to Group IV. Hereby I am attaching the link which has the description about the different groups according to solubility data https:// youtu.be/GVnOX9GmXY0 . As we know that Group IV compounds are Amines.

17. Experiment Observation Inference Test for Amines Carbylamine Test Take 0.2 gm of KOH and add 2 ml of ethanol. Warm the Test tube. To this add a few drops of chloroform and small amount of the sample. Warm gently.     2 ml of ethanol + 0.2 gm of KOH When the solution mixed together Primary amine is present CHCl 3 + small amount of sample Offensive smell Functional Group Analysis

18. Experiment Observation Inference Test for Amines Azo Dye Test Take 0.5 gm of the sample and add 3 ml of conc HCl and then cool in ice. To the cold solution add aqueous solution of sodium nitrite dropwise with shaking. To this add 0.5 gm of beta naphthol in sodium hydroxide solution.     3ml HCl Cooled in ice Aq sol of sodium nitrite + 0.5 gm beta naphthol in NaOH Orange or Red ppt formed Aromatic primary amine is present Functional Group Analysis

19. Conclusion The given compound is Aniline Thank You