Lassaigne's Test Summary Table
| Element Present | Fusion Product | Key Test | Positive Result |
|---|---|---|---|
| N (no S) | NaCN | FeSO4/NaOH/H2SO4 | Prussian blue Fe4[Fe(CN)6]3 |
| S (no N) | Na2S | Sodium nitroprusside | Purple/violet color |
| N + S | NaSCN | FeCl3 | Blood-red Fe(SCN)3 |
| Cl | NaCl | AgNO3 (after HNO3) | White AgCl, soluble in NH3 |
| Br | NaBr | AgNO3 (after HNO3) | Pale yellow AgBr, partial NH3 |
| I | NaI | AgNO3 (after HNO3) | Yellow AgI, insoluble in NH3 |
Functional Group Test Summary Table
| Functional Group | Specific Test | Reagent | Result |
|---|---|---|---|
| Phenol | FeCl3 test | Neutral FeCl3 | Violet/blue/green |
| Aldehyde (all) | Tollens' | [Ag(NH3)2]+ | Silver mirror |
| Aldehyde (aliphatic) | Fehling's | Cu2+/NaOH/tartrate | Brick-red Cu2O |
| Any C=O | 2,4-DNP | 2,4-Dinitrophenylhydrazine | Orange ppt |
| Methyl ketone | Iodoform | I2/NaOH | Yellow CHI3 |
| -COOH | NaHCO3 | Sodium bicarbonate | CO2 effervescence |
| 1° amine | Carbylamine | CHCl3/KOH | Foul isocyanide |
Titration Quick Facts
| Feature | Detail |
|---|---|
| Indicator | None (self-indicating) |
| Temperature | 60–70 °C |
| Endpoint | First persistent faint pink |
| Acidic medium | Dilute H2SO4 (NOT HCl) |
| Mn change | +7 to +2 (gains 5e-) |
| C change | +3 to +4 (loses 2e-) |
| Autocatalytic | Yes (Mn2+ catalyzes reaction) |
Preparations at a Glance
| Product | SMILES | Route |
|---|---|---|
| Acetanilide | CC(=O)Nc1ccccc1 | Aniline + Ac2O, glacial AcOH |
| p-Nitroacetanilide | CC(=O)Nc1ccc([N+](=O)[O-])cc1 | Acetanilide + HNO3/H2SO4, cold |
| Iodoform | C(I)(I)I | Acetone + I2/NaOH |