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 10 of 27
181. Alcohol in which hydroxyl is attached to carbon which is further attached to two alkyl groups is:
- A. Primary alcohol
- B. Tertiary alcohol
- C. Secondary alcohol
- D. None of these
Explanation: A secondary alcohol is characterized by having the hydroxyl group attached to a carbon atom that is bonded to two other carbon atoms.
Correct answer: Secondary alcohol- A. Ethers
- B. Esters
- C. Alkenes
- D. Alkyl halides
Explanation: At high temperature, beta elimination reaction takes place and alcohols are converted to alkenes.
Correct answer: Alkenes- A. Aldehydes
- B. Ketones
- C. Alkenes
- D. Alkynes
Explanation: The controlled oxidation of a primary alcohol with an oxidizing agent like acidified potassium dichromate will remove two hydrogen atoms…
Correct answer: Aldehydes- A. Electrophile
- B. Nucleophile
- C. Acid
- D. Free radical
Explanation: The reaction of an alcohol with sodium metal produces an alkoxide ion (RO⁻).
Correct answer: Nucleophile- A. Organic acid
- B. Inorganic acid
- C. Both organic and inorganic acids
- D. Ether
Explanation: Esterification is the general process of forming an ester. This is most commonly done by reacting an alcohol with a carboxylic acid (an…
Correct answer: Organic acid- A. Alcohol
- B. Acid
- C. Alcohol or acid
- D. Catalyst
Explanation: Tracer studies using oxygen isotopes have shown that during Fischer esterification, the hydroxyl group (-OH) is lost from the carboxylic…
Correct answer: Alcohol- A. C-H
- B. C-O
- C. O- H
- D. C-C
Explanation: During Fischer esterification, isotopic labeling studies have confirmed that the O-H bond of the alcohol is the one that breaks.
Correct answer: O- H- A. 2,4-Dibromophenol
- B. 2-Bromophenol
- C. 2,4,6-Tribromophenol
- D. 3-Bromophenol
Explanation: The -OH group of phenol is a very strong activating group for electrophilic aromatic substitution.
Correct answer: 2,4,6-Tribromophenol- A. C6H5OH > H2O > C2H5OH
- B. H2O > C2H5OH > C6H5OH
- C. C6H5OH > C2H5OH > H2O
- D. H2O > C6H5OH > C2H5OH
Explanation: The correct order of acidity is C6H5OH > H2O > C2H5OH. Phenol is the most acidic because its phenoxide ion is stabilized by resonance…
Correct answer: C6H5OH > H2O > C2H5OH- A. Ketones
- B. Malonic acid
- C. Aldehydes
- D. No reaction
Explanation: Tertiary alcohols do not undergo oxidation with acidified potassium permanganate (KMnO4) because they lack a hydrogen atom on the carbon…
Correct answer: No reaction- A. Aldehyde
- B. Ketone
- C. Carboxylic acid
- D. Ether
Explanation: Strong oxidizing agents, such as acidified potassium dichromate, will oxidize a secondary alcohol to a ketone.
Correct answer: Ketone- A. H2O
- B. C2H5OH
- C. C4H9OH
- D. CH3-CH2-CH2OH
Explanation: Water is more acidic than ethanol because the oxygen atom in water has two lone pairs of electrons, which can be donated to a proton.
Correct answer: H2O- A. Alkane
- B. Alkene
- C. Benzene
- D. Alkyne
Explanation: Alcohols have a carbon straight chain along with an OH group, that is why they are referred as Hydroxy(OH) derivatives of alkanes.
Correct answer: Alkane- A. Hydration of alkene
- B. Hydrogenation of alkenes
- C. Halogenation of alkenes
- D. Oxidation of alkenes
Explanation: In the case of an unsymmetrical alkene, the reaction takes place in accordance with Markovnikov's rule.
Correct answer: Hydration of alkene195. Which of the following reactions can be used for the conversion of ethyl alcohol into acetaldehyde?
- A. Polymerization
- B. Oxidation
- C. Esterification
- D. Reduction
Explanation: The correct answer is Option B: Oxidation. Ethyl alcohol (ethanol) can be oxidized to form acetaldehyde (ethanal) through the process of…
Correct answer: Oxidation- A. Diethyl ether
- B. Dimethyl ether
- C. Ethene
- D. Acetylene
Explanation: When ethyl alcohol reacts with conc.H2SO4 at low temperature (140°C), it gives diethyl ether. Hence option A is correct.
Correct answer: Diethyl ether- A. Methanol
- B. Acetic Acid
- C. Acetic Anhydride
- D. Acetone
Explanation: Only acetaldehyde, ethanol, and methyl ketones give the iodoform test. As acetone has a methyl group adjacent to ketone group, it will…
Correct answer: Acetone- A. Acetone
- B. Acetaldehyde
- C. Ethyl alcohol
- D. n-propyl alcohol
Explanation: The oxidation of secondary alcohol gives ketones. Hence oxidation of secondary propyl alcohol (containing 3 carbon atoms) will give…
Correct answer: Acetone- A. Primary alcohol >secondary alcohol >tertiary alcohol
- B. Methyl alcohol >primary alcohol > secondary alcohol > tertiary alcohol
- C. Primary alcohol < secondary alcohol < tertiary alcohol
- D. Ethanol > primary alcohol > secondary alcohol > tertiary alcohol
Explanation: Option B is correct since the order of reactivity of alcohols when the O-H bond breaks are methyl alcohol(greatest degree of cleavage) ---…
Correct answer: Methyl alcohol >primary alcohol > secondary alcohol > tertiary alcohol- A. -СООН > H2O > C6H5OH > -OH
- B. -СООН >СеН5Он > H2O > -OH
- C. -СООН > -О Н > С6H5OH > H2O
- D. -СООН > Н2O> -ОН > C6H5OH
Explanation: Carboxylic acids are the most acidic, followed by phenols, water, and alcohols
Correct answer: -СООН >СеН5Он > H2O > -OH