Benzamide

systematic analysis of unknown organic compound
result- benzamide

1. SYSTEMATIC ANALYSIS SANDEEP KR YADAV B.Sc. (HONS.) CHEMISTRY RAMJAS COLLEGE UNIVERSITY OF DELHI

2. AIM TO ANALYZE THE GIVEN ORGANIC COMPOUND SYSTEMATICALLY AND PREPARE A SUITABLE CRYSTALLINE DERIVATIVE OF THE SAME .

3. PRELIMINARY ANALYSIS Serial No. EXPERIMENT OBSERVATION INFERENCE 1 PHYSICAL STATE SOLID CARBOXYLIC ACIDS, AMIDES, CARBOHYDRATES, PHENOLS,NITROAMINES MAY BE PRESENT 2 COLOUR COLOURLESS SIMPLE AMIDES, CARBOHYDRATES, ACIDS MAY BE PRESENT 3 ODOUR ODOURLESS CARBOHYDRATES, ACIDS, AMIDES MAY BE PRESENT 4 IGNITION TEST A small amount of organic compound is taken on a spatula and is introduced in blue flame. Sooty flame is observed The compound is aromatic

4. SOLUBILITY TEST A SMALL AMOUNT OF ORGANIC COMPOUND IS TAKEN AND ITS SOLUBILITY IS CHECKED IN FOLLOWING SOLVENTS. Serial No. EXPERIMENT OBSERVATION INFERENCE 1 COLD WATER SPARINGLY SOLUBLE ACIDS, AMIDES, CARBOHYDRATES MAY BE PRESENT 2 HOT WATER SOLUBLE ACIDS, AMIDES MAY BE PRESENT 3 SODIUM BICARBONATE SOLUTION INSOLUBLE CARBOXYLIC ACIDS MAY BE ABSENT 4 DILUTE SODIUM HYDROXIDE INSOLUBLE CARBOXYLIC ACIDS, PHENOLS MAY BE ABSENT 5 DILUTE HYDROCHLORIC ACID INSOLUBLE AMINES MAY BE ABSENT 6 CONCENTRATED SULPHURIC ACID INSOLUBLE AROMATIC HYDROCARBONS MAY BE ABSENT

5. TEST FOR UNSATURATION Serial No. EXPERIMENT OBSERVATION INFERENCE 1 BAEYER’S TEST Small amount of given compound is taken and dissolved in water and few drops of dilute Na 2 CO 3 is added followed by addition of 1-2 % aqueous KMnO 4 solution dropwise with continuous shaking No discharge of purple colour The compound does not contain unsaturation 2 BROMINE SOLUTION TEST To an aqueous solution of given compound , 2% bromine water solution is added dropwise with continuous shaking. No discharge of brown colour The compound does not contain saturation

6. EXTRA ELEMENTS DETECTION Serial No. EXPERIMENT OBSERVATION INFERENCE 1 TEST FOR NITROGEN FERROUS SULPHATE TEST To 2 mL of the Lassaigne’s extract , 1 mL of freshly prepared FeSO 4 solution is added. 2-3 drops of NaOH is added. The content is boiled and dilute H 2 SO 4 is added. Prussian blue colour is observed Confirms the presence of nitrogen 2 TEST FOR SULPHUR LEAD ACETATE TEST The Lassaigne’s extract is acidified with dilute acetic acid and then 4 – 5 drops of lead acetate is added to it. No black precipitate is observed Confirms the absence of sulphur 3 TEST FOR HALOGENS (PRESENCE OF NITROGEN) Lassaigne’s extract is acidified with conc. HNO 3 solution and the content is boiled. The solution is allowed to cool and then AgNO 3 solution is added to it. No precipitate is formed Confirms the absence of halogens

7. REACTIONS INVOLVED DETECTION OF NITROGEN

8. FUNCTIONAL GROUP ANALYSIS Serial No. EXPERIMENT OBSERVATION INFERENCE 1 TEST FOR CARBOXYLIC GROUP SODIUM BICARBONATE TEST To 2 mL saturated sodium bicarbonate solution in a watch glass, small amount of given compound is added. No brisk effervescence is observed Carboxylic group is absent 2 TEST FOR PHENOLIC GROUP FERRIC CHLORIDE TEST To the aqueous solution of organic compound, 1 – 2 drops of neutral ferric chloride solution is added with shaking. No coloured precipitate is observed Phenolic group is absent

9. Serial No. EXPERIMENT OBSERVATION INFERENCE 3 TEST FOR ALCOHOLIC GROUP CERRIC AMMONIUM NITRATE TEST To the aqueous solution of the given compound, 2 – 3 drops of ceric ammonium nitrate reagent is added. No blood red colouration is observed Alcoholic group is absent 4 TEST FOR CARBONYL GROUP DNP TEST To the aqueous solution of organic compound, 6-7 mL of DNP reagent is added with continuous shaking. It is allowed to stand for 5-10 minutes. Then, it is warmed on boiling water bath and is cooled to room temperature. No yellow or orange precipitate is observed Carbonyl group is absent

10. Serial No. EXPERIMENT OBSERVATION INFERENCE 5 TEST FOR AMIDE GROUP (a) HYDROLYSIS TEST In a test tube small amount of given organic compound is taken and 6-7 mL of 10% NaOH is added. The mixture is boiled. A rod dipped in conc. HCl is brought to the mouth of the test tube. Smell of NH 3 observed. Dense white fumes observed. Confirms the presence of amide group (b) HYDROXAMIC TEST A pinch of given compound is taken and 3-4 mL of hydroxylamine hydrochloride solution in ethanol is added. The mixture is boiled for 2-3 minutes. It is cooled and 4-5 mL of freshly prepared ferric chloride solution is added. Change of red colour to violet is observed Confirms the presence of amide group

11. REACTIONS INVOLVED TEST FOR AMIDE GROUP (a) HYDROLYSIS TEST

12. (b) HYDROXAMIC TEST

13. DETERMINATION OF PHYSICAL CONSTANT THE MELTING POINT OF GIVEN COMPOUND IS FOUND TO BE 128 ◦ C USING MELTING POINT APPARATUS. LIST OF PROBABLE COMPOUNDS The given compound contains amide functional group and has melting point 128 ◦ C , it could be :- Sl No. Name of the compound Literature melting point Name of the derivative Literature melting point of the derivative 1 benzamide 128 ◦ C Hydrolysis- Benzoic acid 121 ◦ C

14. PREPARATION OF DERIVATIVE ALKALINE HYDROLYSIS 1 gram of given compound and 20 mL of 10% NaOH solution are taken in a boiling tube fitted with an air condenser. Pumic stones are added and it is refluxed over a wire gauge for 30 minutes till no more ammonia is evolved. It is tested using red litmus paper. After removing the condenser , it is heated for another 5-6 minutes. The boiling tube is cooled and conc. HCl is added. The solution is filtered to get crystals. The crystals obtained is recrystallized using hot water and melting point of recrystallized product is determined. Name of the derivative is BENZOIC ACID . It has melting point 121 ◦ C. Literature melting point is 121 ◦ C.

15. PREPARATION OF DERIVATIVE ALKALINE HYDROLYSIS

16. RESULT The given organic compound is identified as benzamide . The structure of the compound is :-