CBSE Class 12 Chemistry MCQ Alcohols, Phenols and Ethers

CBSE Class 12 Chapter 7 Chemistry MCQs: Chapter 7 of Class 12 Chemistry is one of the most interesting part of organic chemistry that deals with “Alcohols, Phenols and Ethers”. This topic is full of chemical reactions, physical properties, and practical uses that appears often in exam MCQs. The MCQs for CBSE Class 12 Chemistry Chapter 7 – alcohol phenol and ether helps students to test their knowledge and understanding in simple and effective manner.

While preparing for CBSE board class 12 exams, solving Class 12 Chemistry MCQ alcohol phenol and ether is really helpful for quick revision. These alcohol phenol and ether mcqs are designed from latest CBSE class 12 chemistry Syllabus and NCERT Solutions. Students can also practice alcohol phenol and ether mcq learn cbse pattern questions to get concept clarity.

This MCQs questions section also includes alcohols, phenols and ethers questions with answers pdf that make easy to study offline. NCERT Solutions for class 12 chemistry are also connected with this chapter to help you solve tricky concept like hydrogen bonding, ether cleavage and identification of phenolic compounds.

Overview of Alcohols, Phenols, and Ethers

In Class 12 Chemistry, Chapter 7 “Alcohols, Phenols, and Ethers” is a very important part of organic chemistry. It covers the structure, properties, and uses of these compounds in both daily life and industry. Understanding this chapter also helps students solve alcohol phenol and ether mcqs easily and prepare better for board and entrance exams.

• Alcohols: Alcohols are organic compounds that contain one or more hydroxyl (-OH) groups attached to carbon atoms. For example, methyl alcohol (CH3OH) and ethyl alcohol (CH3CH2OH) are common types. Alcohols are very useful in industries and labs because they can be easily converted into other organic compounds.
• Phenols: Phenols have –OH groups directly linked to an aromatic benzene ring. The simplest one is phenol (C6H5OH). These compounds show hydrogen bonding and have both acidic and antiseptic properties.
• Ethers: Ethers are compounds where an oxygen atom is attached to two alkyl or aryl groups. The general formula is R–O–R’. Common examples are CH3OCH3 (dimethyl ether) and CH3OCH2CH3 (ethyl methyl ether). Ethers are widely used as solvents because they do not react easily with other substances.

Solved MCQs on Alcohols, Phenols, and Ethers

These MCQs for CBSE Class 12 Chemistry Chapter 7 – alcohol phenol and ether are designed from the latest CBSE class 12 chemistry Syllabus and help students check how well they understood the topic. Alcohols can be classified into monohydric, dihydric, and trihydric types based on the number of hydroxyl groups. Examples include CH3OH, CH3CH2OH, and (CH2OH)2.

Phenols are prepared when an –OH group replaces a hydrogen atom in benzene. Example compounds are 2-Methylphenol and Benzene-1,3-diol. Ethers are made when oxygen combines with two alkyl or aryl groups, as in methoxyethane.

MCQs on Class 12 Chemistry Chapter 4 Alcohols, Phenols and Ethers

Ques: Heating phenyl methyl ether with HI yields

a) Iodobenzene

b) Phenol

c) Benzene

d) Ethyl chloride

Ans: b

Explanation: Ether cleavage: Ph–O–CH₃ + HI → Ph–OH + CH₃I → phenol + methyl iodide

Ques: Which of the following gives a positive iodoform test?

a) Ethanol

b) Methanol

c) 2-Propanol

d) Phenol

Ans: c

Explanation: Iodoform test is positive for methyl ketones or secondary alcohols having CH₃–CH(OH)– structure.

Ques: CH₃–O–CH(CH₃)₂ + HI → Products. Which is correct?

a) CH₃I + 2-propanol

b) CH₃OH + isopropyl iodide

c) CH₃I + isopropanol

d) CH₃OH + CH₃CH₂I

Ans: c

Explanation: On strong acid cleavage, the ether breaks to the more stable carbocation route.

Ques: Which compound is the most acidic among the following?

a) Ethanol

b) Water

c) Phenol

d) Methanol

Ans: c

Explanation: The phenoxide ion is stabilized by resonance, making phenol stronger acid.

Ques: Among these alcohols, which one reacts fastest with conc. HCl + ZnCl₂ (Lucas test)?

a) Pentan-1-ol

b) 2-methyl butan-1-ol

c) Pentan-2-ol

d) 2-methyl butan-2-ol

Ans: d

Explanation: Tertiary > secondary > primary in reactivity in Lucas test.

Ques: Which cannot be formed by Williamson ether synthesis?

a) Methoxybenzene

b) tert-Butyl ethyl ether

c) Allyl methyl ether

d) Di-tert-butyl ether

Ans: d

Explanation: Tertiary alkyl halides favor elimination over SN2, so di-tert-butyl ether can’t form via Williamson.

Ques: Which reagent is used to distinguish between phenol and benzoic acid?

a) Aqueous NaOH

b) Neutral FeCl₃

c) Tollen’s reagent

d) Molisch reagent

Ans: b

Explanation: Phenol gives violet complex with FeCl₃; carboxylic acids generally do not.

Ques: What is the order of acidity among ethanol, water, and phenol?

a) Ethanol > Water > Phenol

b) Ethanol < Water < Phenol

c) Water < Ethanol < Phenol

d) Phenol > Ethanol = Water

Ans: b

Explanation: phenol > water > ethanol in acidic strength.

Ques: Which alcohol is tertiary?

a) 2-methylbutan-2-ol

b) 3-methylbutan-1-ol

c) 2-methylbutan-1-ol

d) 3-methylbutan-2-ol

Ans: a

Explanation: In 2-methylbutan-2-ol, the –OH carbon is bonded to three other carbons.

Ques: The reaction of phenol with Br₂ (aq) yields:

a) o-Bromophenol

b) p-Bromophenol

c) 2,4,6-Tribromophenol

d) No reaction

Ans: c

Explanation: Phenol activates ring strongly, giving tribromophenol in aqueous bromine. 

Ques: Which of the following is the correct order of dehydration rate of alcohols (acid catalyzed)?

a) 3° > 2° > 1° > CH₃OH

b) 2° > 3° > 1° > CH₃OH

c) 1° > 2° > 3° > CH₃OH

d) CH₃OH > 1° > 2° > 3°

Ans: a

Explanation: Tertiary carbocations are most stable → highest rate.

Ques: Which of the following reagents can oxidise a primary alcohol to aldehyde without further oxidation to acid?

a) CrO₃ in anhydrous medium

b) KMnO₄ in acidic medium

c) Pyridinium chlorochromate (PCC)

d) Heat in presence of Cu at 573K

Ans: a, c, d

Explanation: KMnO₄ in acidic medium is strong, pushes to acid. Others can stop at aldehyde.

Ques: Number of primary alcohol isomers possible for C₅H₁₁OH?

a) 5

b) 4

c) 2

d) 3

Ans: b

Explanation: There are 4 constitutional isomers where –OH is primary. 

Ques: How many alcohols of C₄H₁₀O are optically active (i.e. chiral)?

a) 1

b) 2

c) 3

d) 4

Ans: a

Explanation: Only one structure among these is chiral (2-butanol). 

Ques: In Reimer-Tiemann reaction phenol reacts with CHCl₃ + NaOH to give:

a) Ortho-hydroxy aldehyde (salicylaldehyde)

b) m-Hydroxy benzaldehyde

c) p-Hydroxybenzaldehyde

d) Benzoic acid

Ans: a

Explanation: Reimer-Tiemann yields ortho-formyl derivative typically. 

Ques: Which of the following is used to denature ethanol commercially?

a) Copper sulfate

b) Pyridine

c) Methyl alcohol

d) All of the above

Ans: d

Explanation: All are used to make ethanol unfit for drinking. 

Ques: Which reagent converts ethanol to acetaldehyde (CH₃CHO)?

a) H₂ / Pd

b) LiAlH₄

c) PCC

d) KMnO₄

Ans: c

Explanation: PCC oxidises primary alcohol to aldehyde without further to acid.

Ques: Which isomer has the lowest boiling point among nitrophenols and phenol?

a) p-Nitrophenol

b) m-Nitrophenol

c) o-Nitrophenol

d) Phenol

Ans: c

Explanation: o-Nitrophenol forms intramolecular H-bond, reducing intermolecular bonding, hence lower bp. 

Ques: What is the product when phenol reacts with CH₃Cl + AlCl₃?

a) Anisole

b) O-methyl phenol

c) p-methyl phenol

d) p-cresol

Ans: d

Explanation: electrophilic substitution yields p-cresol likely.

Ques: Which among these has the highest boiling point?

a) Ethanol

b) Diethyl ether

c) Dimethyl ether

d) Methanol

Ans: a

Explanation: Alcohols have hydrogen bonding, increasing boiling point over ethers.

Ques: Which of the following isomerization is possible under acid for 2-methylpropan-1-ol?

a) to isobutene

b) to 2-methylpropan-2-ol

c) to 2-butanol

d) to 2-methylpropanal

Ans: a

Explanation: Dehydration leads to alkene isobutene.

Ques: Which among these ethers is symmetric?

a) Ethoxypropane

b) Methoxybenzene

c) Diethyl ether

d) Isopropyl methyl ether

Ans: c

Explanation: Diethyl ether has identical alkyl groups on both sides.

Ques: Which reaction type is dehydration of alcohol (conc. H₂SO₄)?

a) Substitution

b) Elimination

c) Addition

d) Rearrangement

Ans: b

Explanation: Removing water (H and OH) → elimination. 

Ques: In Williamson synthesis, which condition is essential?

a) Alkoxide must be from a less hindered alcohol

b) Alkyl halide must be primary

c) Reaction medium must be aprotic

d) All of these

Ans: d

Explanation: SN2 constraints demand these conditions.

Ques: The major product in CH₃OCH(CH₃)₂ + HI is

a) CH₃OH + (CH₃)₂CHI

b) CH₃I + (CH₃)₂CHOH

c) CH₃I + (CH₃)₂CHOH

d) CH₃OH + CH₃CH₂I

Ans: c

Explanation: Ether cleavage gives methyl iodide + isopropanol route.

Ques: Which compound is ‘C’ in this sequence:

R–OH → R–X → ROR → ???

a) Water

b) Ethanol

c) Propanone

d) Cumene hydroperoxide

Ans: c

Explanation: The oxidation of ether may yield ketone in designed scheme. (As in illustrative MCQ)

Ques: To distinguish 1-propanol and 2-propanol, you can use:

a) KMnO₄ oxidation + Fehling test

b) Acid dichromate oxidation + Fehling

c) Heating with Cu and then Fehling

d) Concentrated H₂SO₄ + Fehling

Ans: c

Explanation: 2-propanol gives acetone (no Fehling) vs 1-propanol gives ethanal → further changes.

Ques: Which reagent is required to convert anisole to p-bromoanisole?

a) Br₂ / FeBr₃

b) HBr

c) NBS

d) Br₂ (aq)

Ans: a

Explanation: Electrophilic bromination with FeBr₃ yields para product due to activation by –OMe.

Ques: How to convert ethanol to ethene?

a) Oxidation

b) Dehydrogenation

c) Dehydration (conc. acid)

d) Hydrogenation

Ans: c

Explanation: Removing water from ethanol using conc. H₂SO₄.

Ques: Why alcohols have much higher boiling point than corresponding ethers?

a) Larger molecular weight

b) Intramolecular hydrogen bonding

c) Intermolecular hydrogen bonding

d) Ionic interactions

Ans: c

Explanation: Alcohols hydrogen-bond strongly; ethers cannot.

Ques: Which of these is NOT a derivative of water?

a) Alcohols

b) Phenols

c) Ethers

d) Amines

Ans: d

Explanation: Alcohol, phenol, ether (R–OH, Ar–OH, R–O–R) are “water derivatives,” amines are not.

Ques: The electrophile in Reimer-Tiemann reaction is

a) Dichlorocarbene (CCl₂)

b) CHO⁺

c) Cl⁺

d) CO

Ans: a

Explanation: CHCl₃ + base → CCl₃– → CCl₂ (: carbene) is electrophile.

Ques: Which of the following yields phenol when reacted accordingly?

a) Sodium phenoxide + methyl halide

b) Bromobenzene + NaOH (fused)

c) Cumene hydroxide cleavage

d) Friedel–Crafts with benzene

Ans: a, b, c

Explanation: Several routes exist; not d.

Ques: Which set of reagents can oxidise a primary alcohol to aldehyde only?

a) CrO₃ (anhydrous)

b) KMnO₄ (acidic)

c) PCC

d) Heating with Cu

Ans: a, c, d

Explanation: Strong oxidants (KMnO₄) push to acid; others can stop at aldehyde.

Ques: In the sequence: phenol → A → B → C, B is which compound?

a) Salicylaldehyde

b) Benzoic acid

c) Salicylic acid

d) Cinnamic acid

Ans: c

Explanation: Phenol → Reimer-Tiemann → salicylaldehyde → oxidation → salicylic acid.

Ques: Which of the following cannot distinguish phenol and benzyl alcohol?

a) FeCl₃

b) Litmus

c) Br₂ / CCl₄

d) All of the above

Ans: c

Explanation: Both do not decolourize Br₂ in CCl₄; phenol reacts, benzyl alcohol does not.

Ques: Order of boiling points: primary (1°), secondary (2°), tertiary (3°) alcohols?

a) 1° > 2° > 3°

b) 3° > 2° > 1°

c) 2° > 1° > 3°

d) 2° > 3° > 1°

Ans: a

Explanation: 1° has greatest hydrogen bonding and less steric hindrance.

Ques: In which reaction is Williamson’s synthesis used?

a) Ether synthesis

b) Esterification

c) Alkene formation

d) Halogenation

Ans: a

Explanation: Williamson is for ether formation.

Ques: Which of the following is a secondary alcohol?

a) 2-methylbutan-2-ol

b) 3-methylbutan-1-ol

c) 2-methylbutan-1-ol

d) 3-methylbutan-2-ol

Ans: d

Explanation: In 3-methylbutan-2-ol, –OH is on a secondary carbon.

Ques: Which is the correct IUPAC name: CH₃–O–CH(CH₃)₂?

a) 1-Methoxy-1-methylethane

b) 2-Methoxy-2-methylethane

c) 2-Methoxypropane

d) Isopropyl methyl ether

Ans: c (or d in common terms)

Explanation: Systematic: 2-methoxypropane; common: isopropyl methyl ether.

Ques: What is the major organic product when CH₃OCH₂CH₃ reacts with HI?

a) CH₃OH + CH₃CH₂I

b) CH₃I + CH₃CH₂OH

c) CH₃OH + CH₃CH₂OH

d) CH₃I + CH₃CH₂I

Ans: a

Explanation: Ether cleavage gives CH₃OH + ethyl iodide.

Ques: The acidic strength order in the series: p-NO₂ phenol, phenol, p-OCH₃ phenol?

a) p-NO₂ > phenol > p-OCH₃

b) phenol > p-NO₂ > p-OCH₃

c) p-OCH₃ > phenol > p-NO₂

d) phenol > p-OCH₃ > p-NO₂

Ans: a

Explanation: Electron withdrawing (–NO₂) increases acidity; electron donating (–OCH₃) decreases.

Ques: Which reagent cannot oxidise primary alcohol to aldehyde only?

a) PCC

b) CrO₃ (anhydrous)

c) KMnO₄ (acidic)

d) Heating with Cu

Ans: c

Explanation: It is a strong oxidant; will go to carboxylic acid.

Ques: In which reaction do you form anisole (methoxybenzene)?

a) CH₃OH + benzene (Friedel–Crafts)

b) C₆H₅OH + NaOH + CH₃I

c) Benzene + CH₃Cl + AlCl₃

d) Benzene + CH₃COCl + AlCl₃

Ans: b

Explanation: Williamson ether synthesis on phenoxide gives anisole.

Ques: What is the IUPAC name of the compound: CH₃–O–CH₂CH₂OH?

a) Methoxyethanol

b) Ethoxy methanol

c) 2-methoxyethanol

d) 1-methoxyethanol

Ans: a

Explanation: Methoxyethanol is a correct systematic naming.

Ques: Reaction: phenol + SO₃ / H₂SO₄ → intermediate → react with NaOH gives phenolate. What intermediate?

a) Sulfonic acid derivative

b) Sulfide

c) Sulfoxide

d) Salt

Ans: a

Explanation: Sulfonation yields phenol sulfonic acid intermediate.

Ques: Which of these is not a method to produce phenol?

a) Hydrolysis of phenyl diazonium

b) Sulfonation followed by base fusion

c) Friedel–Crafts with benzene

d) Cumene oxidation

Ans: c

Explanation: Friedel–Crafts doesn’t produce phenol directly.

Ques: Which ether is most easily cleaved by HBr?

a) Diethyl ether

b) Ethyl phenyl ether

c) tert-Butyl methyl ether

d) Diphenyl ether

Ans: c

Explanation: Tertiary side helps cleavage; diphenyl ether is too stable.

Ques: Which has a higher pKa (i.e. weaker acid), phenol or ethanol?

a) Phenol

b) Ethanol

Ans: b (ethanol is weaker acid, higher pKa)

Explanation: Phenol pKa ~10; ethanol ~16.

Ques: Which reagent is used to prepare ethers from alcohols (intramolecular dehydration)?

a) H₂SO₄ (conc.)

b) HCl

c) Br₂

d) NaOH

Ans: a

Explanation: Concentrated sulphuric acid at moderate temperature causes dehydration to ether (if possible).