Qualitative test for phenol .pptx

Qualitative test for phenol

1. Qualitative tests for Phenols

2. 1.Litmus test 2. Ferric chloride test 3. Liebermann's test 4. Bromine water test 5. Phthalein Dye test

3. 1.Litmus test: Principle: Phenol is acidic in nature it convert blue litmus into red litmus paper. Procedure: Carboxylic acid also gives this test. Compare to carboxylic acid phenol is weakly acidic and it does not give an effervescence with aqueous sodium carbonate. Observe the change in color of paper Place a drop of organic solution or small crystal on moist blue litmus paper

4. 2. Ferric chloride test: Principle: Aqueous solution of phenols react with freshly prepared ferric chloride solution to give colored complex. Different types of phenols undergo same reaction but gives different colour. Reagent: Neutral solution of FeCl3 is prepared by adding dilute NaOH solution to ferric chloride drop by drop until a small but permanent brown precipitate appears. Filter the solution and use. Procedure: Observation: Phenol, Cresol and Resorcinol: Violet / blue color. Catechol : Green color Hydroquinone : Violet / transient blue color Pyrogallol : Blue rapidly changing to red Organic compound dissolve in water Add few drops of ferric chloride regent. Observe the change in color.

5. 3. Liebermann's test: Principle: Phenol react with con. H2SO4 and sodium nitrate(NaNO2) to give quinone monoxime (yellow colour) which further treated with excess phenol and H2SO4 gives indophenol (blue colour) on dilution it changes to red & further treated with NaOH to give blue colour salt of Indophenol .

6. Procedure: 1 ml phenol + Sodium nitrite solution in test tube Add 1 ml conc. H2SO4 and shake Solution turns to red (phenol present) Blue colour solution obtain Heat gently & allow to cool Add phenol Yellow colour Gives blue colour Dilute the solution with water Add NaOH solution

7. 4. Bromine water test: Principle: Phenol undergo electrophilic substitution with bromine. When bromine water is added to the aqueous solution of phenol the brown colour of bromine disappears & a white precipitate of 2,4,6tribromo phenol if formed. Reagent: Take 5ml of bromine add 100 ml of distilled water and shake well.

8. Procedure: Dissolve sample in glacial acetic acid Bromine colour disappears and white precipitate forms Observation: Formation of white precipitate shows the presence of phenols.

9. 5. Phthalein Dye test: Principle: Phenol on heating with Phthalic anhydride in the presence of con.H2SO4 forms a colourless condensation product called Phenolphthalein. On further reaction with dilute NaOH solution gives pink colour fluorescent compound called Fluorescein. Phenol Reddish pink o-cresol Red m-cresol Blue or violet blue 1-naphthol Green 2-naphthol Faint green Resorcinol Yellow green fluorescence Hydroquinone Deep purple

10. Procedure: Phenol + 200 mg of phthalic anhydride Add few drops of H2SO4 & heat it for 2-3 minutes. Cool and pour into beaker containing dilute NaOH Dilute the mixture with equal volume of water. Observe the colour change in a white background

11. Structure and uses of Phenol, Cresol, Resorcinol, Naphthols

12. PHENOL Uses: Used in the production of Bakelite (resin of phenol and formaldehyde) Bakelite is used in electric switches and automobiles etc…. Used in study and extraction of bio-molecules (nucleic acids from tissue sample) Used in cosmetic industry - in the manufacturing of sunscreens, skin lightning creams, hair colouring solutions. Used to disinfect skin and relieve itching. Used in surgical ingrown toenail treatment. Hydroxy benzene Carbolic acid C6H5OH It is a white crystalline solid that is volatile

13. Cresol Uses: Mixture of cresol is used as disinfectant, preservative, wood preservatives. O-cresol is used as solvent, disinfectant, reactant. m -cresol – herbicides, antioxidants and also used in photographic developer and explosives. P-cresol - antioxidants, dye industries, Fragrance industries. Hydroxy toluene C7H8O Colourless crystal/ Thicker liquid / Greasy

14. Resorcinol Uses: Used as antiseptic Used in treatment of gastric ulcer Used in vaginal itching and irritation Used in production of di azo dyes and used as analytic reagent. White solid, turns pink upon exposure to air. Resorcin Benzene diol 1,3-benzene diol C6H6O2

15. Naphthols Colourless white solid crystal C10H8O Uses: Used in synthesis of insecticides and drugs Used in preparation of drugs

16. 1-Napthol 1-napthol is used in making several azo dyes. 1- napthol is precursor to : insecticides- Carbaryl Pharmaceuticals- Nadolol Antidepressant- Sertraline Anti-protozoan- Atovaquone 2-Napthol Used in making dyes, pigments, fluorescent whiteners, tanning agents, antioxidants, antiseptics. Used in pharmaceuticals: Antifungal- Tolnaftate Ant rheumatic- Naproxen Used in production of perfumes. Used in synthesis of fungicides. Used to make important intermediate such as 3-hydroxy-2-naphthalenecarboxylic acid (BON), 2-naphtholsulfonic acids. Used as antiseptic in scabies.