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 Β· page 27 of 27
- A. 1-Pentene
- B. 3-Pentene
- C. 2-Methylbutane
- D. 3-Methylbutane
Explanation: The major product is 2-pentene because it is the most stable alkene formed after carbocation rearrangement and follows Zaitsev's rule.
Correct answer: 3-Pentene- A. C2H5OC2H5 + H2O
- B. C2 H4
- C. C2 H5 OH
- D. C2 H6
Explanation: At 140Β°C in the presence of sulfuric acid two molecules of ethanol are dehydrated (lose a molecule of water) to form ether.
Correct answer: C2H5OC2H5 + H2O- A. A) CH3CH2OH + HCl --> CH3CH2Cl + H2O
- B. B) CH3CH2OH + HBr --> CH3CH2Br + H2O
- C. C) CH3CH2OH + HI --> CH3CH2I + H2O
- D. D) Both B & C
Explanation: The correct answer is Option D The reaction of ethanol with HBr generally does not require a ZnCl2 catalyst because HBr is a more reactiveβ¦
Correct answer: D) Both B & C- A. Aldehyde
- B. Ketone
- C. Ether
- D. None of the above
Explanation: A tertiary alcohol can't form this carbonyl group: the tertiary custom has three single bonds to other C- atoms and one single bond to theβ¦
Correct answer: None of the above- A. They contain more alkyl group
- B. They have no alpha-hydrogen
- C. Suitable oxidizing agent is not available
- D. None of the above
Explanation: Tertiary alcohols are not oxidized by acidified sodium or potassium dichromate(VI) solution - there is no reaction whatsoever.
Correct answer: They have no alpha-hydrogen526. Epoxide obtained from isobutylene is further hydrolyzed in the presence of acid The final product is
- A. 2,3 - Butanediol
- B. 1,2 - Butanediol
- C. 2-Methyl-1,2-Propandiol
- D. All of them
Explanation: Epoxide obtained from isobutylene is further hydrolyzed in the presence of acid The final product is 2-Methyl-1,2-Propandiol
Correct answer: 2-Methyl-1,2-Propandiol- A. 2 - Butanol
- B. 1 - Butanol
- C. 2 - Methyle β 2 - Proponal
- D. All of these have the same boiling point
Explanation: Among the isomeric alcohols you mentioned, 1-butanol has the highest boiling point because it has a longer carbon chain, which allows forβ¦
Correct answer: 1 - Butanol- A. Per Iodic acid
- B. Lad tetra acetate
- C. Acidified KMNO4
- D. Both (A) (B)
Explanation: When periodic acid (HIO4) reacts with ethylene glycol, it actually oxidizes ethylene glycol into a compound called glycolic acid, notβ¦
Correct answer: Per Iodic acid- A. Ethene
- B. Ether
- C. Ethyl hydrogen sulphat
- D. None of the above
Explanation: When ethanol is dehydrated with concentrated sulfuric acid (conc MO) at a temperature of 140Β°C, it undergoes a chemical reaction calledβ¦
Correct answer: Ethene- A. 10 Alcohol
- B. 20 Alcohol
- C. 30 Alcohol
- D. Carboxylic acid
Explanation: When CH3MgBr, which is methylmagnesium bromide, reacts with CH2O, which is formaldehyde, it undergoes a nucleophilic addition reaction.
Correct answer: 10 Alcohol- A. Vic - diol
- B. Gem - diol
- C. Triol
- D. None of these
Explanation: Trimethylene glycol, also known as 1,3-propanediol, is a vicinal diol. In a vicinal diol, the hydroxyl (-OH) groups are attached toβ¦
Correct answer: Vic - diol- A. Methyl alcohol
- B. Ethyl alcohol
- C. Benzyl alcohol
- D. P - cresol
Explanation: An aromatic alcohol is an alcohol that contains an aromatic ring, such as a benzene ring, with a hydroxyl group (-OH) attached.
Correct answer: Benzyl alcohol- A. Alkyl chloride
- B. Acid chlorides
- C. Aldehydes
- D. Ketones
Explanation: The appearance of cloudiness in the Lucas test for alcohols is due to the formation of alkyl chloride.
Correct answer: Alkyl chloride- A. Ethanol
- B. Phenol
- C. Ethanal
- D. Propanone
Explanation: If bromine water is added to a solution of phenol in water, the bromine water/aqueous bromine is decolarized and a white precipitate isβ¦
Correct answer: Phenol- A. Thiol
- B. Alcohol
- C. Phenol
- D. Ether
Explanation: Thiol (R-SH) typically contains the most acidic proton. This is because the sulfur atom in thiol is less electronegative than oxygen inβ¦
Correct answer: Thiol