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 15 of 27
- A. Benzene
- B. Cyclohexanol
- C. Toluene
- D. Aldehyde
Explanation: Catalytic hydrogenation of phenol is industrially important for the synthesis of cyclohexanone and cyclohexanol as the intermediate for…
Correct answer: Cyclohexanol- A. C - C
- B. C - H
- C. C - O
- D. O - H
Explanation: O−H bond undergoes cleavage most readily because O and H differ markedly in their electronegativity and further oxygen being highly…
Correct answer: O - H- A. Absolute alcohol
- B. Methylated spirit
- C. Wood spirit
- D. Rectified sprit
Explanation: Denatured spirit is also known as Alcohol or ethyl alcohol is used for manufacturing alcoholic beverages.
Correct answer: Methylated spirit- A. Benzyl alcohol
- B. Benzene
- C. Phenol
- D. A,C
Explanation: Benzyl alcohols(BA) is an aromatic alcohol used as a solvent in the production of fragrances/perfumes, paints and adhesives.Benzyl alcohol…
Correct answer: Benzyl alcohol- A. Alcohol is reduced
- B. O-H bond in ethanoic acid is broken
- C. O-H bond in ethanol is broken
- D. Acid is oxidized
Explanation: SN reaction of alcohol. O-H bond of alcohol breaks and electrophilic portion of acid combines with O of alcohol.
Correct answer: O-H bond in ethanol is broken- A. Formation of H2 gas
- B. Release of H2 gas
- C. Brick red precipitate
- D. Yellow precipitate
Explanation: Yellow ppt is a correct indication which is used for difference between Methanol and ethanol.
Correct answer: Yellow precipitate- A. SN1
- B. Either SN1 and SN2
- C. SN2
- D. Both and SN1 SN2
Explanation: Secondary alcohols can undergo nucleophilic substitution reactions via the SN1 mechanism, although SN2 reactions are more common due to…
Correct answer: Both and SN1 SN2- A. Oxide ion
- B. Carbon ion
- C. Hydronium ion
- D. Oxonium ion
Explanation: The correct option for the protonated ether is D) Oxonium ion. The oxonium ion is formed when a proton is added to the oxygen atom in an…
Correct answer: Oxonium ion- A. PCI5
- B. PCI3
- C. HCl/ZnCl2
- D. SOCl2
Explanation: The correct option for the reagent that can produce a greater number of moles of ethyl chloride (C2H5Cl) when reacting with an excess of…
Correct answer: PCI3- A. 3
- B. 5
- C. 4
- D. 6
Explanation: The correct option for the number of resonating structures of the phenoxide ion is B) 5.
Correct answer: 5- A. CH3CH2OH
- B. CH3CHO
- C. CH3COOH
- D. HCOOCH3
Explanation: The correct answer is CH3CH2OH, which is ethanol. Ethanol and dimethyl ether are isomers because they share the same molecular formula…
Correct answer: CH3CH2OH292. The question is:
- A. Propyne
- B. Propanal
- C. Propene
- D. Propane
Explanation: In the case of an unsymmetrical alkene, the reaction takes place in accordance with Markovnikov's rule.
Correct answer: Propene- A. 3
- B. 2
- C. 1
- D. Zero
Explanation: 1,3,5-pentanetriol is a five-carbon chain with hydroxyl groups on the 1st, 3rd, and 5th carbons.
Correct answer: 3- A. H-bonding
- B. repulsive forces
- C. attractive forces
- D. dipole forces
Explanation: The correct answer is dipole forces (Option D). Ethyl alcohol (ethanol) contains an ethyl group, which is a non-polar hydrocarbon part…
Correct answer: dipole forces- A. Acid-base
- B. Redox
- C. Electrophilic
- D. Nucleophilic
Explanation: Esterification is a nucleophilic substitution reaction. Esterification is the process of combining an organic acid (RCOOH) with an alcohol…
Correct answer: Nucleophilic- A. 3-Methylbutan-2-ol
- B. 2-Methylpropan-2-ol
- C. Ethanol
- D. Methanol
Explanation: Tertiary alcohols are most easily dehydrogenated followed by secondary and primary alcohols being the most difficult to dehydrogenate.
Correct answer: 2-Methylpropan-2-ol- A. Haloalkane
- B. Alkyl halide & POCI3
- C. Alkyl halide & H3PO3
- D. Alkyl halide & H3PO4
Explanation: CH3CH2OH + PCl3 ----> CH3CH2Cl + HCl + H3PO3 Ethanol reacts with PCl3 to produce ethyl chloride and phosphorous acid.
Correct answer: Alkyl halide & H3PO3- A. NH3
- B. HCI
- C. K2Cr2O7 / H2SO4
- D. PCI3
Explanation: Reaction of alcohol with PCl3 produces H3PO3 and alkyl chloride. It does not release water.
Correct answer: PCI3299. The temperature required for the dehydration of ethanol into ethene in the presence of H2SO4 is:
- A. 130°C
- B. 175°C
- C. 170°C
- D. 180°C
Explanation: Dehydration of alcohols in to alkenes occur at 180°C in the presence of concentrated sulfuric acid.
Correct answer: 180°C- A. makes it basic
- B. decreases its acidity
- C. Stablises the phenoxide ion
- D. allows it to precipitate in an aqueous solution
Explanation: e- withdrawing groups stabilize negative charge.
Correct answer: Stablises the phenoxide ion