chemistry

PHENOLS
1. Phenols are aromatic hydroxy compounds.
2. Cresols are methyl phenols
3. Picric acid — 2,4,6 - trinitro phenol
4. Catechol — 1,2 - didhydroxy benzene
5. Resorcinol — 1,3 - dihydroxy benzene
6. Hydroquinone or Quinol — 1,4 - dihydroxybenzene
7. Pyrogallol — 1,2,3 - trihydroxy benzene
8. Seliwanoff’s reagent : Resorcinol + conc. HCl
9. The middleoil fraction of coal tar contains phenol and naphthalene
10. Benzene + Propene ——> cumene ————> cumene hydroperoxide ————> phenol + acetone
11. By-product in cumene - Phenol process. Acetone
12. Aniline —————> Benzene diazonium chloride ——> phenol
13. Phenol turns pink due to oxidation- quinones are formed
14. Phenol is acidic due to resonance
15. Nitrophenols are stronger acids than phenols
16. Cresols are weaker acids than phenols
17. Phenols are weaker than carboxylic acids
18. Picric acid is highly acid - soluble in NaHCO3 solution
19. Acidity of phenols: picric acid > p -nitrophenol > m - nitrophenol > phenol
20. With neutral FeCl3 soln., phenol gives a violet colour
21. Salicylaldehyde and salicylic acid with neutral FeCl3, gives a violet colour
22. Phenol dissolves in NaOH forming sodium phenoxide and water
23. Halogen acids do not react with phenols
24. Phenol forms triphenyl phosphate with PCl5
25. Phenol + C6H5COCl ——> phenyl Benzoate -- Schotten - Baumann reaction
26. Phenol decolourises bromine water forming 2,4,6 - tribromophenol
27. Bromination in the presence of CS2 gives a mixture of O-bromo phenol and P-bromo phenol
28. Phenol with dil. HNO3 gives a mixture of O-nitrophenol and P-nitrophenol
29. O-nitro phinol and P - nitrophenol can be seperated by steam distillation
30. Phenol with conc. HNO3 gives picric acid
31. Kolbe’s reaction
Phenol ———> sodium phenoxide ——> sodium salicylate —> salicylic acid
32. Elb’s persulphate oxidation: Phenol ————> Quinol
33. Liberman’s nitroso reaction ( Test for phenol)