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 25 of 27
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Carbon atom that carries the -OH group is attached to two alkyl groups.
Correct answer: Option A- A. Oxidation
- B. Fermentation
- C. Hydration
- D. Hydrogenation
Explanation: Ethanol can be oxidized to ethanoic acid by using oxidizing agents such as potassium permanganate (KMnO4), chromium trioxide (CrO3) or…
Correct answer: Oxidation- A. Secondary alcohol
- B. Primary alcohol
- C. Tertiary alcohol
- D. Carboxylic acid
Explanation: A tertiary alcohol has the hydroxyl group on a carbon atom, which is bonded to two other carbon atoms.
Correct answer: Tertiary 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 oxidised
Explanation: In the given reaction, ethanol and ethanoic acid react in the presence of a strong acid catalyst (usually concentrated sulphuric acid) to…
Correct answer: O-H bond in ethanol is broken- A. Alkenes
- B. Alkynes
- C. Alkyl halides
- D. Ketones
Explanation: When secondary alcohols are oxidized with Na2Cr2O7 in the presence of H2SO4, they are converted to ketones.
Correct answer: Ketones- A. A
- B. B
- C. C
- D. D
Explanation: When CH3-CH2-OH is oxidized in the presence of K2Cr2O7 and H2SO4, the product formed is ethanal (acetaldehyde), which can further oxidize…
Correct answer: A- A. C2H5Cl only
- B. C2H5Cl and HCl
- C. C2H5Cl, POCl3 and HCl
- D. C2H5Cl and POCl3
Explanation: When ethanol (C2H5OH) reacts with phosphorus pentachloride (PCl5), it undergoes a substitution reaction where the hydroxyl group (-OH) is…
Correct answer: C2H5Cl, POCl3 and HCl- A. Anesthetic
- B. Knocking agent
- C. Freezing agent
- D. Anti-freezing agent
Explanation: Ethylene glycol is used as an antifreeze agent and polyester.
Correct answer: Anti-freezing agent- A. Lucas test
- B. Iodoform test
- C. Baeyer's test
- D. Silver mirror test
Explanation: The Lucas test differentiates between primary, secondary, and tertiary alcohols.
Correct answer: Lucas test- A. Amino group
- B. Hydroxyl group
- C. Halide group
- D. Hydride group
Explanation: When a -OH group(hydroxyl group) containing organic compound is reacted with with phosphorus pentachloride, it forms HCI an halogen by the…
Correct answer: Hydroxyl group- A. Methanol
- B. Lactic acid
- C. Pyridine
- D. Acetone
Explanation: Methanol, pyridine and acetone are able to denature ethanol.Denaturation refers to the process of rendering alcohol undrinkable or…
Correct answer: Lactic acid- A. By Lucas test
- B. By silver mirror test
- C. By oxidation
- D. By Iodoform test
Explanation: The solution in the ethanol test tube should go cloudy and then a yellow precipitate of tri-iodomethane (iodoform) should be seen.
Correct answer: By Iodoform test- A. Calcium oxide
- B. Calcium chloride
- C. Calcium carbonate
- D. Carbon monoxide
Explanation: if we add lime (CaO) to the rectified spirit then the water of the mixture can be absorbed by the lime.
Correct answer: Calcium oxide- A. Primary
- B. Secondary
- C. Tertiary
- D. Polyhydride
Explanation: It is a tertiary alcohol. We can recognize the tertiary alcohol by seeing whether the C atom attached to the OH group (also known as alpha…
Correct answer: Tertiary- A. Less acidic than water
- B. Less basic than phenol
- C. More acidic than phenol
- D. More acidic than water
Explanation: The concentration of H+ ions determines the acidity. More H+ ions means the solution is more acidic as in the case of water while alcohol…
Correct answer: Less acidic than water- A. Ortho hydroxy benzene sulphonic acid
- B. Meta hydroxy benzene sulphonic acid
- C. Ortho and para hydroxy benzene sulphonic acid
- D. Para hydroxy benzene sulphonic acid
Explanation: Explanation:This product is formed in the reaction of phenol with concentrated sulfuric acid.
Correct answer: Ortho and para hydroxy benzene sulphonic acid- A. Br2/H2O
- B. FeSO4
- C. Cl2/H2O
- D. FeCl3
Explanation: Explanation:An aqueous solution of phenol reacts with bromine water to give white ppt of 2,4,6-tribromophenol .
Correct answer: Br2/H2O- A. 1.2 x 10^-10
- B. 1.2 x 10^10
- C. 1.3 x 10^10
- D. 1.3 x 10^-10
Explanation: A is incorrect.B is incorrect.C is incorrect.D is correct as disassociation constant of phenol is 1.3 x10-10 (fact)
Correct answer: 1.3 x 10^-10- A. Picric acid
- B. Nitro phenol
- C. Benzoic acid
- D. Malonic acid
Explanation: Picric acid is 2,4,6-trinitrophenol. Picric acid has a structure consisting of a phenolic ring with three nitro groups (-NO2) attached…
Correct answer: Picric acid- A. 2,4,6-tribromophenol
- B. 2-bromophenol
- C. 4-bromophenol
- D. Phenol
Explanation: Since the OH group has an electron donating effect, it is an ortho-para director. The following reaction occurs:
Correct answer: 2,4,6-tribromophenol