1. PHENOLS

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

3. Ignition test (Dry heat test):
Inflammability
Change in appearance
Change in color flame
Change in odor
Residue
Comment
All inflammable, luminous, smoky
All melting
All no change in color flame
All on change in odor
All no residue
All the compounds are aromatic
Solubility:
All soluble in H2O
L.p.: No change
Comment All the compounds are neutral

4. Green color which rapidly darkens
Phenol
Resorcinol
Catechol
Preliminary test:
Soda lime
On cold:
On hot:
30% NaOH
FeCl3
Conc. H2SO4
Penolic odor
No reaction
Not done
Penolic odor
No reaction for all
No reaction for all
Very diluted phenols + 1– 3 drops FeCl3
Green color which rapidly darkens
violet – blue color
Not done for all
No reaction for all
No reaction for all

5. General class group test for phenols:
Azo – dye formation test ≡ Diazotization test
Phenol
Resorcinol
Catechol
1 drop aniline (red color) + dil.HCl (until dissolve) + NaNO2 (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% NaOH (until phenol dissolved)
(2)
Add (1) on (2) gradually
((Azo – dye formation))
Orange – red color or ppt
No azo – dye form
{Decomposition, dark purple color}
Because the presence of hydroxyl
gp near to each other

6. Due to Alizarin indicator
Phenol
Resorcinol
Catechol
Specific test:
Phthalein test
Phenol + phthalic anhydride + 4 drops Conc. H2SO cool Dry test tube pour in beaker containing fussion
20 ml 10% NaOH
Pink color
Due to phenol
phthaline
((indicator))
Green fluorescence
H2O
Fluorescence
Blue color
Due to Alizarin indicator