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.
Last updated
Read the Alcohols and Phenols notesFree MDCAT chapter notes with key terms535 questions · page 13 of 27
- A. 85%
- B. 90%
- C. 95%
- D. 100%
Explanation: This is correct. Rectified spirit is approximately 95% ethanol.
Correct answer: 95%- A. Tollen's synthesis
- B. Fehling's Synthesis
- C. Willamson's synthesis
- D. Grignard's synthesis
Explanation: This is the reaction of an alkoxide with an alkyl halide to form an ether.
Correct answer: Willamson's synthesis- A. Tertiary > Secondary > Primary
- B. Primary > Secondary > Tertiary
- C. Secondary < Primary < Tertiary
- D. Tertiary < Secondary < Primary
Explanation: The dehydration of alcohols typically proceeds through a carbocation intermediate (E1 mechanism).
Correct answer: Tertiary > Secondary > Primary- A. Invertase + Diastase
- B. Zymase + Invertase
- C. Invertase + Zymase
- D. Diastase + Zymase
Explanation: Diastase + Zymase) - Correct: Diastase breaks starch into maltose, and Zymase ferments glucose to ethanol.
Correct answer: Diastase + Zymase- A. Zymase
- B. Invertase
- C. Urease
- D. Diastase
Explanation: Urease) - Correct: Hydrolyzes urea into NH₃ and CO₂
Correct answer: Urease- A. Phenate
- B. Anisole
- C. Diphenyl ether
- D. Diethyl ether
Explanation: This reaction is an example of the Williamson ether synthesis. Phenol is first deprotonated by NaOH to form the sodium phenoxide ion…
Correct answer: Anisole- A. Red, Colourless, Blue
- B. Red, Blue, Colourless
- C. Colourless, Red, Blue
- D. Blue, Red, Violet
Explanation: The Victor-Meyer test is a classic color test to distinguish between primary, secondary, and tertiary alcohols.
Correct answer: Red, Blue, Colourless- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Structure: Cyclohexene with a =CH₂ group (i.e., methylene cyclohexane).Explanation:This is the correct product.The -CH₂OH group loses…
Correct answer: Option A- A. C2H6O
- B. C3H8O
- C. C4H10O
- D. C5H12O
Explanation: By converting the mass percentages to a mole ratio, the empirical formula is found to be C₄H₁₀O.
Correct answer: C4H10O- A. Me-O-Me
- B. Et-O-Et
- C. iPr-O-iPr
- D. tBu-O-tBu
Explanation: Ethers form peroxides via a free radical mechanism at the α-carbon (the carbon next to the ether oxygen).
Correct answer: iPr-O-iPr- A. CH3C+HCH3
- B. CH3-CH2-CH3
- C. CH3CH2CH2-
- D. CH3CH2CH2+
Explanation: Dehydration of n-propyl alcohol first forms a primary carbocation (CH₃CH₂CH₂⁺), which rearranges to the more stable secondary carbocation…
Correct answer: CH3C+HCH3- A. Methanol
- B. Acetone
- C. Pyridine
- D. All of these
Explanation: Denatured alcohol is ethanol that has been made unfit for human consumption by the addition of poisonous or foul- tasting substances.
Correct answer: All of these- A. Primary alcohols
- B. Teritary alcohol
- C. Secondary alcohols
- D. All of the above
Explanation: In both isobutyl alcohol and isopentyl alcohol, the hydroxyl (-OH) group is attached to a carbon atom that is bonded to only one other…
Correct answer: Primary alcohols- A. Methanoic acid
- B. Ethanoic acid
- C. Propanoic acid
- D. Butanoic acid
Explanation: The controlled oxidation of ethanol (a two-carbon alcohol) produces ethanoic acid (acetic acid), which is a two-carbon carboxylic acid.
Correct answer: Ethanoic acid- A. R-ONa
- B. H2 gas
- C. Both A and B
- D. No reaction takes place
Explanation: This statement is incorrect because tertiary alcohols are resistant to oxidation as they lack a hydrogen atom on the carbon bearing the…
Correct answer: Both A and B- A. 1
- B. 2
- C. 3
- D. 4
Explanation: A diol is an alcohol with two hydroxyl (-OH) groups. When reacted with an excess of an active metal like sodium, both acidic protons will…
Correct answer: 1- A. Addition
- B. Evaporation
- C. Elimination
- D. Esterification
Explanation: Many esters have characteristic fruity or pleasant smells and are used as artificial flavorings.
Correct answer: Esterification- A. Alkoxy alkanoate
- B. Alkane alkanoic acid
- C. Alkoxy alkanote
- D. Alkyl aloxyalkane
Explanation: The functional group isomer of an ether (alkoxyalkane) is an alcohol (alkanol).
Correct answer: Alkoxy alkanoate- A. Ether
- B. Organic acid
- C. Ester
- D. Alkene
Explanation: The acid-catalyzed dehydration of alcohols can lead to two different products.
Correct answer: Ether- A. o-Nitrophenol
- B. m-Nitrophenol
- C. p-Nitrophenol
- D. Both A and C
Explanation: The nitration of phenol with dilute nitric acid is a moderated electrophilic substitution.
Correct answer: Both A and C