PHENOLS Phenol Resorcinol Catechol Solid flaky Solid fine

PHENOLS

Phenol Resorcinol Catechol Solid, flaky. Solid, fine powder. Structures Physical properties: State Color Odor Solid, crystalline. White Buff Phenolic odor gray

Ignition test (Dry heat test): Inflammability All inflammable, luminous, smoky Change in appearance All melting Change in odor All on change in odor Residue All no residue Comment All the compounds are aromatic Solubility: All soluble in H 2 O L. p. : No change Comment All the compounds are neutral

Phenol Resorcinol Catechol Preliminary test: Soda lime On cold: Penolic odor No reaction On hot: Not done Penolic odor 30% Na. OH On cold: No reaction for all On hot: Very diluted phenols + 1– 3 drops Fe. Cl 3 On cold: violet – blue color Not done for all On hot: Conc. H 2 SO 4 On cold: On hot: No reaction for all Green color which rapidly darkens

General class group test for phenols: Azo – dye formation test ≡ Diazotization test 1 drop aniline (red color) + dil. HCl (until dissolve) + Na. NO 2 (sod. Nitrite solution) until faint pale yellow color (1) {Diazonium salt formed} It is unstable because that we must put it in ice, without ice it will decompose few phenol + 10% Na. OH (until phenol dissolved) (2) Add (1) on (2) gradually Phenol Resorcinol ((Azo – dye formation)) Orange – red dye Catechol Azo – dye form {Dark purple or brown dye}

Phenol Resorcinol Catechol Specific test: Phthalein test Dry test tube Phenol + phthalic anhydride + 4 drops Conc. H 2 SO 4 pour in beaker containing cool fussion 20 ml 10% Na. OH Pink color Due to phenol phthaline ((indicator)) Green fluorescence H 2 O Fluorescence Bluish Brown color Due to Alizarin indicator

IR spectrum of phenol