| Alkene (C=C) | Br₂(aq) | Decolourised (brown → colourless) | Also decolourises KMnO₄/H⁺ |
| Alcohol (–OH) | Na | Bubbles (H₂) | No reaction with Na₂CO₃ |
| Aldehyde (–CHO) | Tollen's / warm | Silver mirror | Also reacts with Fehling's (red ppt) |
| Aldehyde / Ketone | 2,4-DNPH | Orange precipitate | Ketones: no reaction with Tollen's |
| Methyl carbonyl (CH₃CO–) | I₂ in alkaline | Yellow ppt (CHI₃) | Also: CH₃CH(OH)– gives same result |
| Carboxylic acid (–COOH) | Na₂CO₃ | Bubbles (CO₂) | Also reacts with Na |
| Halogenoalkane (–X) | NaOH + AgNO₃; reflux | White (Cl), Cream (Br), Yellow (I) | Different hydrolysis rates due to bond energy |
| Alcohol / Aldehyde | K₂Cr₂O₇/H⁺ | Orange → green | No change with ketones |