Free Alcohols and Phenols MCQs with Answers
535 Alcohols and Phenols MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alcohols are classified as primary, secondary or tertiary and studied through their hydrogen bonding, acidity, oxidation and reactions with active metals, acids and halogenating agents. Phenols require separate treatment because the hydroxyl group is attached to an aromatic ring, making their acidity and electrophilic substitution different from ordinary alcohols.
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Read the Alcohols and Phenols notesFree MDCAT chapter notes with key terms535 questions · page 4 of 27
- A. cyclohexane
- B. n - hexane
- C. 1 - hexanol
- D. cyclohexanol
Explanation: Hydrogenation saturates both the aromatic ring and the phenolic system under catalytic conditions with nickel and heat, producing…
Correct answer: cyclohexanol- A. vegetable oil
- B. coaltar
- C. wood
- D. none of these
Explanation: Phenol was first isolated by Runge from coal tar, a complex mixture obtained during the destructive distillation of coal.
Correct answer: coaltar- A. Benzene
- B. Benzoic acid
- C. Phenoxide
- D. Cyclohexane
Explanation: Zinc removes the oxygen-containing hydroxyl group from phenol during heating, reducing phenol to benzene: C6H5OH + Zn produces C6H6 + ZnO.
Correct answer: Benzene- A. C2H2OH
- B. H2CO3
- C. C6H5OH
- D. H3PO3
Explanation: Carbolic acid is the traditional name for phenol, C6H5OH, because it was historically obtained from coal tar.
Correct answer: C6H5OH- A. monocarboxylc acid
- B. dicarboxylic acid
- C. aromatic carboxylic acid
- D. none of these
Explanation: Picric acid is 2,4,6-trinitrophenol, so it contains a phenolic -OH group and nitro groups, but no carboxyl group.
Correct answer: none of these- A. phthalic acid
- B. carbolic acid
- C. Maleic acid
- D. Succinic acid
Explanation: Carbolic acid is the common name of phenol, C6H5OH, which has a hydroxyl group directly attached to benzene rather than a -COOH group.
Correct answer: carbolic acid- A. phenol is unsaturated
- B. 2-bromophenol is insoluble in water
- C. a hydroxy group makes the benzene ring more susceptible to electrophilic attack
- D. acid-base reaction
Explanation: The hydroxy group donates electron density into the benzene ring by resonance, activating the ring and directing electrophilic…
Correct answer: a hydroxy group makes the benzene ring more susceptible to electrophilic attack- A. NaBH4
- B. HBr
- C. Na2Cr2O7
- D. Grignard reagent
Explanation: When an ether is treated with HBr, it undergoes an acid-catalyzed cleavage reaction to form an alcohol and an alkyl halide.
Correct answer: HBr- A. 2-Ethanoic acid
- B. 2-Ethanoate
- C. Diethyl ether
- D. Ethanol
Explanation: Ethanol can be oxidized to produce acetaldehyde, which is an aldehyde. The oxidation can be carried out using an oxidizing agent such as…
Correct answer: Ethanol- A. C6H5OH
- B. C6H5CH(OH)2
- C. C6H5CH2OH
- D. C6H5COOH
Explanation: Benzyl alcohol is indeed represented by the chemical formula C6H5CH2OH.
Correct answer: C6H5CH2OH- A. 2,3-dihydroxy butane 1,4-dioic acid
- B. 2,3-Dihydroxy butanedioic acid
- C. 2,3-Dihydroxy butanoic acid
- D. 2,2-Dihydroxy butanoic acid
Explanation: Tartaric acid is also known as 2,3-dihydroxybutanedioic acid. Its chemical formula is C4H6O6.
Correct answer: 2,3-Dihydroxy butanedioic acid- A. Methanal
- B. Methanol
- C. Carbonic acid
- D. Methane
Explanation: Under the conditions of high temperature (450°C) and high pressure (200 atm) in the presence of a catalyst like ZnO+Cr₂O, water gas (a…
Correct answer: Methanol- A. Diastase-maltase-zymase
- B. Zymase-maltase-diastase
- C. Maltase-diastase-zymase
- D. Diastase-zymase-maltase
Explanation: The fermentation of starch involves a series of enzymes, typically including α-amylase, maltase, and zymase.
Correct answer: Maltase-diastase-zymase- A. Oxygen
- B. Hydrogen
- C. Nascent oxygen (O)
- D. Nascent hydrogen (H)
Explanation: The reaction involving potassium dichromate (K2Cr2O7) and sulfuric acid (H2SO4) does indeed generate nascent oxygen (O).The overall…
Correct answer: Nascent oxygen (O)- A. Primary alcohol
- B. Secondary Alcohols
- C. Tertiary alcohol
- D. All of the above
Explanation: Primary, secondary, and tertiary alcohols can undergo elimination reactions to form alkenes in the presence of acidic potassium dichromate.
Correct answer: All of the above- A. Conc. HCl and anhydrous SOCl₂
- B. Conc. HCl and anhydrous CaCl₂
- C. Conc. HCl and anhydrous PCl₃
- D. Conc. HCl and anhydrous ZnCl₂
Explanation: The Lucas test distinguishes primary, secondary and tertiary alcohols by their reactivity with Lucas reagent - concentrated HCl and…
Correct answer: Conc. HCl and anhydrous ZnCl₂- A. Alcohol
- B. Acetic acid
- C. Water
- D. Phenol
Explanation: The given dissociation constant (Ka) value of 1.3x10⁻¹⁰ is characteristic of phenol.The dissociation constant (Ka) is a measure of the…
Correct answer: Phenol- A. Oxidation
- B. Elimination
- C. Condensation polymerization
- D. Additional polymerization
Explanation: Treating phenol with formaldehyde in the presence of a dilute base results in the formation of Bakelite through a condensation…
Correct answer: Condensation polymerization- A. Ca(OH)2
- B. CaCO3
- C. CaCl2
- D. CaO
Explanation: Absolute alcohol is obtained when the rectified spirit is treated with anhydrous calcium oxide (CaO) to remove the remaining water…
Correct answer: CaO- A. Alkyl halides
- B. Alkyl amine
- C. Alkanes
- D. Alkynes
Explanation: When alcohol reacts with phosphorus halides such as phosphorus trichloride (PCl₃) or phosphorus tribromide (PBr₃), it undergoes…
Correct answer: Alkyl halides