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Libermann's Test
Libermann's test gives blue/green color with phenols. Specific for phenolic -OH group.
How It Works
1
Three Unknown Compounds
Tubes A, B, C contain phenol, alcohol, and carboxylic acid.
2
Add Reagents
First NaNO₂/H₂SO₄, then NaOH to make alkaline.
3
Observe Color
Blue color = Phenol. No blue = Alcohol or Carboxylic acid.
Reaction Key
Phenol:
Blue/green color in alkaline medium
Alcohol:
No blue color
Carboxylic Acid:
No blue color