Organic Chemistry carries over 30% of the Chemistry section on the MDCAT. Rote memorization of products fails when examiners change the substrate; understanding reaction mechanisms and reagent functions guarantees 100% accuracy.
| Diagnostic Test | Reagent Used | Positive Observation | Target Functional Group |
|---|---|---|---|
| Tollens' Test | Ammoniacal $AgNO_3$ | Silver Mirror on glass wall | Aldehydes (Reducing sugars) |
| Fehling's Solution | Alkaline $CuSO_4$ + Tartrate | Brick-red precipitate ($Cu_2O$) | Aliphatic Aldehydes |
| Lucas Test | Anhydrous $ZnCl_2$ + conc. $HCl$ | Immediate turbidity (3° alcohol) | Distinguish 1°, 2°, 3° Alcohols |
| Iodoform Test | $I_2$ + aqueous $NaOH$ | Yellow crystalline precipitate ($CHI_3$) | Methyl Ketones & $CH_3-CH(OH)-$ groups |
| 2,4-DNPH Test | Brady's Reagent | Yellow/Orange-red precipitate | Carbonyl Group ($C=O$) |