PYQ Analysis — Previous Year Question Patterns — Notes

Frequently Tested Concepts (NEET 2017–2024)

Year Range	Concept Tested	Question Type	Frequency
Multiple years	PCC vs $KMnO_{4}$ product from 1° alcohol	Product identification MCQ	Very High
Multiple years	Phenol acidity ordering with substituents	Arrange in order MCQ	High
Multiple years	Kolbe reaction product and position	Named reaction product MCQ	High
Multiple years	Reimer-Tiemann intermediate (: $CCl_{2}$ )	Mechanism MCQ	Medium
Multiple years	Williamson synthesis: correct halide choice	Reagent selection MCQ	High
Multiple years	Lucas test result for alcohol type	Observation-based MCQ	Medium
Multiple years	Phenol + $Br_{2}$ / $H_{2}O$ product (no catalyst)	Product/condition MCQ	Medium

Sample PYQ-Style Questions

Q1. Which of the following reagents converts cyclohexanol to cyclohexanone? Answer: PCC or $K_{2}Cr_{2}O_{7}$ (both convert 2° alcohol → ketone; $KMnO_{4}$ also works)

Q2. The product of Kolbe reaction of sodium phenoxide with $CO_{2}$ followed by acidification is: Answer: Salicylic acid (SMILES:OC(=O)c1ccccc1O)

Q3. Phenol reacts with bromine water to give a white precipitate. The product is: Answer: 2,4,6-tribromophenol

Strategy: For reagent questions, always ask: (a) Is it oxidation or reduction? (b) Is the reagent mild or strong? (c) What are the conditions (anhydrous? aqueous?)