NEET-UG — Concept Mastery Quiz

This NEET-style quiz targets the most-tested ideas of Alcohols, Phenols and Ethers: classification and nomenclature, preparation methods and named reactions, acidity of alcohols and phenols, distinguishing tests (Lucas, Victor Meyer, FeCl3_3, iodoform), the cumene process, Williamson synthesis and ether cleavage. Read each option carefully — NEET rewards clean recall of NCERT facts. Each question has one best answer with a concise explanation. Target 25+ questions; keep a steady pace.

NEET Previous Year Questions — Practice Quiz

Q1. Glycerol is classified as a A) monohydric alcohol B) dihydric alcohol *C) trihydric alcohol D) phenol Explanation: Glycerol (propane-1,2,3-triol) has three -OH groups, so it is trihydric.

Q2. The IUPAC name of isopropyl alcohol is A) propan-1-ol *B) propan-2-ol C) 2-methylpropan-2-ol D) propan-1,2-diol Explanation: (CH3_3)2_2CHOH is propan-2-ol.

Q3. Wood spirit is A) ethanol *B) methanol C) glycerol D) phenol Explanation: Methanol was obtained by destructive distillation of wood, hence wood spirit.

Q4. Which is the most acidic? A) ethanol B) water *C) phenol D) methanol Explanation: Phenol's conjugate base (phenoxide) is resonance-stabilised, making it the most acidic of these.

Q5. The enzyme that converts sucrose to glucose and fructose is A) zymase *B) invertase C) diastase D) maltase Explanation: Invertase hydrolyses sucrose; zymase then ferments the monosaccharides to ethanol.

Q6. Phenol gives a violet colour with A) NaHCO3_3 *B) neutral FeCl3_3 C) Tollens reagent D) Fehling solution Explanation: Neutral ferric chloride forms a violet iron(III)-phenoxide complex with phenols.

Q7. In the Lucas test a tertiary alcohol gives turbidity A) after 5 minutes *B) immediately C) only on heating D) never Explanation: 3° alcohols form the carbocation fastest, so the insoluble chloride appears immediately.

Q8. The reagent for the Lucas test is A) conc. HNO3_3 + H2_2SO4_4 *B) conc. HCl + anhydrous ZnCl2_2 C) NaOH + CHCl3_3 D) I2_2 + NaOH Explanation: Lucas reagent is concentrated HCl with anhydrous zinc chloride.

Q9. Acid-catalysed hydration of propene follows A) anti-Markovnikov addition *B) Markovnikov addition C) free-radical addition D) syn addition only Explanation: Acid hydration gives the Markovnikov product, propan-2-ol.

Q10. The product of the cumene process along with phenol is A) acetaldehyde *B) acetone C) formaldehyde D) acetic acid Explanation: Acid cleavage of cumene hydroperoxide gives phenol and acetone.

Q11. Which alcohol gives no reaction with Lucas reagent at room temperature? A) tert-butyl alcohol B) isopropyl alcohol *C) n-butyl alcohol D) sec-butyl alcohol Explanation: A primary alcohol (n-butyl) does not react with Lucas reagent at room temperature.

Q12. Salicylaldehyde is prepared from phenol by the A) Kolbe reaction *B) Reimer-Tiemann reaction C) Williamson synthesis D) cumene process Explanation: Phenol + CHCl3_3 + NaOH (Reimer-Tiemann) gives salicylaldehyde.

Q13. Salicylic acid is prepared from phenol by the A) Reimer-Tiemann reaction *B) Kolbe reaction C) Friedel-Crafts reaction D) Sandmeyer reaction Explanation: Kolbe's reaction (sodium phenoxide + CO2_2) gives salicylic acid.

Q14. The Williamson synthesis is an example of A) electrophilic substitution *B) SN2 reaction C) elimination D) oxidation Explanation: An alkoxide displaces halide from a primary alkyl halide by SN2.

Q15. Bromine water reacts with phenol to give A) o-bromophenol *B) 2,4,6-tribromophenol C) bromobenzene D) p-bromophenol Explanation: The activated phenol ring is trisubstituted to 2,4,6-tribromophenol (white precipitate).

Q16. Which has the highest boiling point? A) dimethyl ether *B) ethanol C) propane D) ethyl chloride Explanation: Ethanol forms intermolecular hydrogen bonds, giving the highest boiling point.

Q17. Ethers are fairly soluble in water because A) they ionise *B) the ether oxygen H-bonds with water C) they react with water D) they are non-polar Explanation: The lone pairs on the ether oxygen accept hydrogen bonds from water.

Q18. In the Victor Meyer test a secondary alcohol gives a A) blood-red colour *B) blue colour C) no colour D) green colour Explanation: Victor Meyer: 1° red, 2° blue, 3° colourless.

Q19. Oxidation of a secondary alcohol gives a A) carboxylic acid *B) ketone C) aldehyde D) ether Explanation: Secondary alcohols are oxidised to ketones.

Q20. Reaction of phenol with NaOH gives A) phenyl chloride *B) sodium phenoxide C) anisole D) salicylic acid Explanation: Phenol is acidic enough to react with NaOH, giving sodium phenoxide.

Q21. Which does NOT react with sodium metal to give H2_2? A) ethanol B) phenol *C) diethyl ether D) propan-1-ol Explanation: Ethers have no O-H, so they do not react with sodium to release hydrogen.

Q22. The conversion of an alkene to an alcohol with B2_2H6_6/H2_2O2_2 is A) Markovnikov, anti addition *B) anti-Markovnikov, syn addition C) Markovnikov, syn addition D) anti-Markovnikov, anti addition Explanation: Hydroboration-oxidation is anti-Markovnikov and proceeds with syn addition.

Q23. Anisole is A) phenol *B) methoxybenzene C) benzaldehyde D) cumene Explanation: Anisole is methoxybenzene, C6_6H5_5OCH3_3.

Q24. Methanol is toxic because in the body it is oxidised to A) acetic acid *B) formaldehyde and formic acid C) acetone D) ethanol Explanation: Methanol is metabolised to formaldehyde and formic acid, which cause blindness and death.

Q25. Which alcohol is optically active? A) propan-2-ol *B) butan-2-ol C) 2-methylpropan-2-ol D) ethanol Explanation: Butan-2-ol has a chiral carbon (C-2 bears four different groups).

Q26. Dehydration of a 1° alcohol to a symmetrical ether occurs at A) 443 K *B) 413 K with conc. H2_2SO4_4 C) room temperature D) above 500 K Explanation: At about 413 K with conc. H2_2SO4_4, two 1° alcohol molecules form a symmetrical ether.