Class 12 Chemistry MCQ Chapter 8 Aldehydes, Ketones and Carboxylic Acids
Are you aiming to score high marks in Chemistry? Our Class 12 Chemistry MCQ Chapter 8 Aldehydes, Ketones and Carboxylic Acids English Medium collection is specially designed for AHSEC students who want to strengthen their preparation through extensive objective-question practice.
This chapter introduces students to some of the most important organic compounds, including aldehydes, ketones, and carboxylic acids. The MCQs cover key topics such as nomenclature, preparation methods, physical and chemical properties, oxidation and reduction reactions, nucleophilic addition reactions, acidity of carboxylic acids, and the identification of organic compounds through various chemical tests. These concepts frequently appear in board examinations and competitive tests, making thorough practice essential.
Prepared according to the latest AHSEC syllabus, these multiple-choice questions help students develop a deeper understanding of reaction mechanisms and improve their analytical skills. Each question is designed to test conceptual knowledge while helping students become familiar with the objective question pattern used in examinations.
Whether you are revising the chapter before an exam or looking for extra practice, these MCQ solutions will help you boost your confidence, improve accuracy, and perform better in your Higher Secondary examinations.
Part II
Aldehydes, Ketones and Carboxylic Acids
VSA & MCQ
I. Short Question-Answer
Q. What are aldehydes?
Ans: Organic compounds containing –CHO group.
Q. What are ketones?
Ans: Compounds containing >C=O group within carbon chain.
Q. What are carboxylic acids?
Ans: Compounds containing –COOH group.
Q. General formula of aldehydes.
Ans: R–CHO
Q. General formula of ketones.
Ans: R–CO–R′
Q. General formula of carboxylic acids.
Ans: R–COOH
Q. What is carbonyl group?
Ans: Functional group >C=O
Q. Why carbonyl carbon is electrophilic?
Ans: Due to polar C=O bond.
Q. What is nucleophilic addition?
Ans: Addition of nucleophile to carbonyl carbon.
Q. Order of reactivity of carbonyl compounds.
Ans: Aldehydes > Ketones
Q. What is oxidation of aldehydes?
Ans: Conversion to carboxylic acids.
Q. What is reduction of carbonyl compounds?
Ans: Conversion to alcohols.
Q. What is Tollens’ test?
Ans: Test for aldehydes giving silver mirror.
Q. What is Fehling’s test?
Ans: Test giving red precipitate with aldehydes.
Q. What is Cannizzaro reaction?
Ans: Disproportionation of aldehydes without α-H.
Q. What is aldol condensation?
Ans: Reaction forming β-hydroxy aldehyde/ketone.
Q. What is α-hydrogen?
Ans: Hydrogen attached to carbon next to carbonyl.
Q. What is keto-enol tautomerism?
Ans: Equilibrium between keto and enol forms.
Q. Why carboxylic acids are acidic?
Ans: Due to resonance stabilization of carboxylate ion.
Q. What is esterification?
Ans: Reaction of acid with alcohol to form ester.
Q. Write esterification reaction.
Ans: R–COOH + R′–OH ⇌ R–COOR′ + H₂O
Q. What is decarboxylation?
Ans: Removal of CO₂ from carboxylic acid.
Q. What is Hell–Volhard–Zelinsky reaction?
Ans: α-halogenation of carboxylic acids.
Q. What is acyl group?
Ans: R–CO–
Q. What is formaldehyde?
Ans: HCHO
Q. What is acetone?
Ans: CH₃COCH₃
Q. What is acetic acid?
Ans: CH₃COOH
Q. What is benzoic acid?
Ans: C₆H₅COOH
Q. What is reduction of carboxylic acid?
Ans: Conversion to primary alcohol.
Q. What is nucleophilic substitution in acids?
Ans: Replacement of –OH group.
II. Multiple Choice Questions (MCQs)
Q. Aldehyde functional group is:
(a) –COOH
(b) –CHO
(c) –OH
(d) –NH₂
Ans: (b)
Q. Ketone group is:
(a) –CHO
(b) –CO–
(c) –COOH
(d) –OH
Ans: (b)
Q. Carboxylic acid group is:
(a) –COOH
(b) –CHO
(c) –NH₂
(d) –OH
Ans: (a)
Q. Most reactive carbonyl compound:
(a) Ketone
(b) Aldehyde
(c) Acid
(d) Ester
Ans: (b)
Q. Tollens’ test gives:
(a) Red ppt
(b) Silver mirror
(c) Gas
(d) Colourless
Ans: (b)
Q. Fehling’s test gives:
(a) Blue
(b) Red ppt
(c) Green
(d) Yellow
Ans: (b)
Q. Aldol condensation requires:
(a) No α-H
(b) α-H
(c) Only acid
(d) Only base
Ans: (b)
Q. Cannizzaro reaction occurs in:
(a) Aldehyde with α-H
(b) Aldehyde without α-H
(c) Ketone
(d) Acid
Ans: (b)
Q. Carboxylic acids are:
(a) Basic
(b) Neutral
(c) Acidic
(d) Salty
Ans: (c)
Q. Esterification produces:
(a) Alcohol
(b) Ester
(c) Acid
(d) Aldehyde
Ans: (b)
Q. Keto-enol tautomerism involves:
(a) Addition
(b) Substitution
(c) Rearrangement
(d) Polymerisation
Ans: (c)
Q. Acetone is:
(a) Aldehyde
(b) Ketone
(c) Acid
(d) Ester
Ans: (b)
Q. Formaldehyde is:
(a) Ketone
(b) Aldehyde
(c) Acid
(d) Alcohol
Ans: (b)
Q. Assertion: Aldehydes are more reactive than ketones.
Reason: Less steric hindrance.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (b)
Q. Assertion: Carboxylic acids are acidic.
Reason: Resonance stabilizes carboxylate ion.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (d)
Q. Assertion: Tollens’ test identifies aldehydes.
Reason: Aldehydes reduce Ag⁺ to Ag.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (c)
Q. Assertion: Aldol condensation needs α-H.
Reason: Enolate formation occurs.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (a)
Q. Assertion: Cannizzaro reaction occurs without α-H.
Reason: No enolate formation.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (b)
Q. Assertion: Esterification is reversible.
Reason: Equilibrium reaction.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (d)
Q. Assertion: Ketones are less reactive.
Reason: Greater steric hindrance.
(a) Both true, R correct explanation
(b) Both true, R not correct explanation
(c) A true, R false
(d) A false, R true
Ans: (c)
