🎨
Azo Dye Test
1° aromatic amines form orange-red azo dye via diazotization + coupling. Bright and vivid!
How It Works
1
Three Unknown Amines
Tubes A, B, C contain 1° aromatic amine, 1° aliphatic amine, and 2° amine.
2
Diazotize + Couple
NaNO₂/HCl at 0-5°C forms diazonium salt, then add β-naphthol.
3
Observe Dye Formation
Orange-red dye = 1° aromatic amine. N₂ bubbles = 1° aliphatic. Nothing = 2°.
Reaction Key
1° Aromatic Amine:
Orange-red azo dye (diazonium + β-naphthol)
1° Aliphatic Amine:
N₂ effervescence (unstable diazonium)
2° Amine:
No dye, no reaction