Which technique among the following, is most appropriate in separation of a mixture of 100 mg of p-nitrophenol and picric acid?
- (A)Steam distillation
- (B)2-5 ft long column of silica gel
- (C)Sublimation
- (D)Preparative TLC (Thin Layer Chromatography)✓ Correct
Answer: (D)
Solution
p-Nitrophenol and picric acid have different polarities due to their hydrogen bonding patterns:
These differences result in different Rf values on a silica gel TLC plate. For a small quantity (100 mg), Preparative TLC is the most appropriate technique as it can effectively separate compounds with different Rf values and is suitable for milligram-scale separations.
Answer: (D) Preparative TLC.
p-nitrophenol 
picric acid
- p-Nitrophenol shows intermolecular hydrogen bonding.
- Picric acid shows intramolecular hydrogen bonding.
These differences result in different Rf values on a silica gel TLC plate. For a small quantity (100 mg), Preparative TLC is the most appropriate technique as it can effectively separate compounds with different Rf values and is suitable for milligram-scale separations.
Answer: (D) Preparative TLC.
JEE Main · 2022 · 26 Jul 2022 · Shift 1 · Single correct option