Here’s a detailed Functional Group Analysis Table with proper chemical equations for Class 12:
| Functional Group | Test Name | Reagents Used | Positive Observation | Chemical Equation | Example |
|---|---|---|---|---|---|
| Alcohol (-OH) | Lucas Test | ZnCl₂ + Conc. HCl | Immediate turbidity (3°), after 5 min (2°), no reaction (1°) | R-OH + HCl → RCl + H₂O (ZnCl₂ catalyzed) | Ethanol (C₂H₅OH) |
| Phenol (-OH on benzene ring) | Ferric Chloride Test | FeCl₃ solution | Violet/blue-green color | C₆H₅OH + FeCl₃ → C₆H₅OFe + HCl | Phenol |
| Bromine Water Test | Br₂ water | Decolorization & white ppt. | C₆H₅OH + 3Br₂ → C₆H₂Br₃OH + 3HBr | Phenol | |
| Aldehyde (-CHO) | Tollen’s Test | Ammoniacal AgNO₃ | Silver mirror forms | R-CHO + 2[Ag(NH₃)₂]⁺ + 3OH⁻ → R-COO⁻ + 2Ag↓ + 2H₂O + 4NH₃ | Formaldehyde (HCHO) |
| Fehling’s Test | Fehling A & B (Cu²⁺ solution) | Brick-red precipitate | R-CHO + 2Cu²⁺ + 5OH⁻ → R-COO⁻ + Cu₂O↓ (red) + 3H₂O | Acetaldehyde (CH₃CHO) | |
| Ketone (>C=O) | 2,4-DNP Test | 2,4-Dinitrophenylhydrazine | Yellow/orange ppt. | R-CO-R’ + H₂NNH(C₆H₃(NO₂)₂) → R-C=NNH(C₆H₃(NO₂)₂) + H₂O | Acetone (CH₃COCH₃) |
| Carboxylic Acid (-COOH) | Sodium Bicarbonate Test | NaHCO₃ solution | Effervescence due to CO₂ gas | R-COOH + NaHCO₃ → R-COO⁻Na⁺ + CO₂↑ + H₂O | Acetic Acid (CH₃COOH) |
| Litmus Test | Blue litmus paper | Turns red (acidic nature) | CH₃COOH → CH₃COO⁻ + H⁺ | Acetic Acid | |
| Amines (-NH₂, -NHR, -NR₂) | Litmus Test | Red litmus paper | Turns blue (basic nature) | R-NH₂ + H₂O ⇌ R-NH₃⁺ + OH⁻ | Aniline (C₆H₅NH₂) |
| Carbylamine Test | CHCl₃ + Alc. KOH | Foul-smelling isocyanide | R-NH₂ + CHCl₃ + 3KOH → R-NC + 3KCl + 3H₂O | Methylamine (CH₃NH₂) | |
| Amide (-CONH₂) | Sodium Hydroxide Test | NaOH solution | Ammonia gas evolves (pungent smell) | R-CONH₂ + NaOH → R-COO⁻Na⁺ + NH₃↑ | Acetamide (CH₃CONH₂) |
| Ester (-COO-) | Hydroxylamine Test | Hydroxylamine + FeCl₃ | Wine-red color | R-COO-R’ + NH₂OH → R-CO-NHOH + R’-OH | Ethyl acetate (CH₃COOCH₂CH₃) |
| Fruity Smell Test | Heating with alcohol & acid | Fruity odor | R-COOH + R’-OH → R-COO-R’ + H₂O (acid catalyst) | Methyl acetate (CH₃COOCH₃) | |
| Haloalkane (R-X) | Silver Nitrate (AgNO₃) Test | AgNO₃ in ethanol | White (Cl), Pale yellow (Br), Yellow (I) ppt. | R-X + AgNO₃ → AgX↓ + R-NO₃ | Chloroethane (C₂H₅Cl) |