NCERT MCQ Solutions for Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids

NCERT MCQ Solutions for Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids provide accurate and concept-based answers to multiple-choice questions from the chapter. NCERT Textbook Objective Questions solutions help students revise key topics like nomenclature, structure, preparation and reactions of carbonyl and carboxylic compounds. Designed as per NCERT patterns, they strengthen understanding of mechanisms such as nucleophilic addition, oxidation and reduction. These MCQs are useful for board exams as well as other competitive tests, ensuring thorough and efficient practice.

Class 12 Chemistry MCQ Solutions
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Class 12 Chemistry Chapter 8 MCQ Solutions

Q1. The carbonyl group (>C=O) consists of a carbon-oxygen double bond. What is the hybridization of the carbonyl carbon atom?

[A]. sp²
[B]. dsp²
[C]. sp³
[D]. sp

Q2. According to IUPAC nomenclature, the suffix used for naming open-chain aldehydes is

[A]. -ol
[B]. -one
[C]. -al
[D]. -oic acid

Q3. The common name for the simplest ketone, CH₃COCH₃, is

[A]. Acetaldehyde
[B]. Acetone
[C]. Propanone
[D]. Formaldehyde

Q4. The carbon-oxygen double bond in carbonyl compounds is polar, making the carbon atom

[A]. Non-polar
[B]. Amphoteric
[C]. Nucleophilic (Lewis base)
[D]. Electrophilic (Lewis acid)

Class 12 Chemistry Chapter 8 Objective Questions

Chapter 8 of Class 12 Chemistry NCERT, Aldehydes, Ketones and Carboxylic Acids, is a key part of organic chemistry. It explores carbonyl-containing compounds and their reactions in great detail. Students learn the IUPAC and common names, structure, preparation methods and chemical properties of aldehydes, ketones and carboxylic acids. The nucleophilic addition reactions, oxidation-reduction behavior and tests like Tollens’ and Fehling’s are essential for differentiation and identification. The acidity of α-hydrogens and the mechanism of aldol and Cannizzaro reactions are important for deeper conceptual clarity. MCQs from this chapter target understanding of these scientific principles and reaction pathways. Students often face questions testing functional group recognition, acidity order, reaction conditions and product prediction. These MCQs are precise, conceptual and integral for mastering key organic reaction patterns.

Q5. The Rosenmund reduction involves the hydrogenation of an acyl chloride using palladium on barium sulphate catalyst to produce

[A]. An alcohol
[B]. A ketone
[C]. A carboxylic acid
[D]. An aldehyde

Q6. The Stephen reaction involves the reduction of nitriles using stannous chloride and HCl, followed by hydrolysis, to yield

[A]. Carboxylic acids
[B]. Ketones
[C]. Aldehydes
[D]. Amines

Q7. Oxidation of methylbenzene (toluene) with chromyl chloride (CrO₂Cl₂) followed by hydrolysis yields benzaldehyde. This reaction is called

[A]. Etard reaction
[B]. Clemmensen reduction
[C]. Rosenmund reduction
[D]. Gatterman-Koch reaction

Q8. Friedel-Crafts acylation of benzene with an acyl chloride (RCOCl) in the presence of anhydrous AlCl₃ produces

[A]. An aldehyde
[B]. A ketone
[C]. A carboxylic acid
[D]. An alkylbenzene

Class 12 Chemistry Chapter 8 MCQ with Answers

Q9. Which compound has a higher boiling point, propanal (CH₃CH₂CHO) or propan-1-ol (CH₃CH₂CH₂OH)?

[A]. Propanal
[B]. Propan-1-ol
[C]. Cannot be determined
[D]. They have nearly identical boiling points

Q10. Aldehydes are generally more reactive than ketones towards nucleophilic addition reactions because

[A]. Aldehydes are less polar
[B]. Ketones have stronger C=O bonds
[C]. Ketones form more stable intermediates
[D]. Aldehydes have less steric hindrance and a more electrophilic carbonyl carbon

Q11. The addition of HCN to aldehydes or ketones yields

[A]. Cyanohydrins
[B]. Oximes
[C]. Hydrazones
[D]. Acetals

Q12. The reaction of aldehydes and ketones with ammonia derivatives (H₂N-Z) typically involves nucleophilic addition followed by

[A]. Hydrolysis
[B]. Reduction
[C]. Dehydration (loss of water)
[D]. Oxidation
Class 12 Chemistry chapter 8 MCQ for Concepts in Carbonyl, Carboxyl Compounds

Q13. Which reagent is used in the Clemmensen reduction to reduce the carbonyl group (>C=O) to a methylene group (-CH₂-)?

[A]. Hydrazine and KOH/ethylene glycol
[B]. LiAlH₄
[C]. NaBH₄
[D]. Zinc-amalgam (Zn-Hg) and concentrated HCl

Q14. Tollens’ test involves the reaction of an aldehyde with ammoniacal silver nitrate solution and results in the formation of

[A]. Evolution of CO₂ gas
[B]. A bright silver mirror (Ag)
[C]. A red precipitate (Cu₂O)
[D]. A yellow precipitate (CHI₃)

Q15. The haloform reaction (e.g., iodoform test) is given by aldehydes and ketones that possess which structural feature?

[A]. An aromatic ring
[B]. At least one alpha-hydrogen
[C]. A carbon-carbon double bond
[D]. A methyl group attached to the carbonyl carbon (CH₃CO–)

Q16. The Aldol condensation reaction occurs between two aldehyde or ketone molecules possessing

[A]. An aromatic ring
[B]. No alpha-hydrogens
[C]. At least one alpha-hydrogen
[D]. Only beta-hydrogens
Class 12 Chemistry chapter 8 MCQs for Revision

MCQs from Class 12 Chemistry chapter 8 are needed not only for CBSE board exams but also for competitive exams. This is because the chapter covers many high-frequency topics such as resonance stability, acidity of compounds, electrophilic and nucleophilic behavior and reagent-based transformations. For instance, questions involving the iodoform test, Hell-Volhard-Zelinsky reaction or aldol condensation test a student’s ability to link theory to practical organic chemistry. Board exams typically include MCQs on naming, preparation and specific reaction outcomes. Competitive exams, on the other hand, include application-based MCQs requiring logical reasoning and understanding of electronic effects. Hence, rigorous MCQ practice ensures readiness for time-sensitive problem-solving, helping students recall the correct mechanism or concept instantly during high-stakes tests.

Q17. Aldehydes lacking alpha-hydrogens undergo which reaction when treated with concentrated alkali?

[A]. Cannizzaro reaction
[B]. Haloform reaction
[C]. Wolff-Kishner reduction
[D]. Haloform reaction

Q18. Carboxylic acids are generally stronger acids than phenols because

[A]. Alcohols are stronger acids than carboxylic acids
[B]. The phenoxide anion is more resonance stabilized than the carboxylate anion
[C]. Phenols cannot form hydrogen bonds
[D]. The carboxylate anion is more resonance stabilized than the phenoxide anion

Q19. The Hell-Volhard-Zelinsky (HVZ) reaction involves the halogenation of carboxylic acids (having an alpha-hydrogen) at the

[A]. Gamma-position
[B]. Alpha-position
[C]. Gamma-position
[D]. Carboxyl carbon

Q20. Carboxylic acids undergo decarboxylation (lose CO₂) when their sodium salts are heated with

[A]. LiAlH₄
[B]. Red phosphorus and HI
[C]. Sodalime (NaOH + CaO)
[D]. Concentrated H₂SO₄

Why is practicing Class 12 Chemistry Chapter 8 MCQ essential for students?

Practicing MCQs from Chapter 8 is important because this chapter includes complex reaction mechanisms and interconversions. Multiple-choice questions test your understanding of nucleophilic addition, reduction, oxidation, acidity of carboxylic acids and reactions like aldol and Cannizzaro. These MCQs strengthen your grasp on chemical logic and help revise multiple concepts quickly. They also train you to spot correct answers under time pressure, which is useful for scoring high in board exams and building a strong base for competitive exams.

What type of questions are asked from Chapter 8 in exams?

In exams like NEET and JEE, questions from Chapter 8 often test mechanistic understanding and reagent recognition. For instance, you may be asked to identify a product formed when a ketone reacts with NaBH₄ or to choose the correct sequence for converting aldehydes to acids. MCQs here demand application of theory, not just rote memorization. They assess your ability to predict outcomes and compare acidic strengths, functional groups and reaction selectivity—making Class 12 Chemistry chapter 8 a frequent topic in entrance exams.

How should I prepare MCQs for Class 12 Chemistry Chapter 8?

Start by mastering the NCERT textbook thoroughly—focus on key reactions, mechanisms and differences between aldehydes, ketones and carboxylic acids. Make a table of important reagents and their effects. Practice chapter-wise MCQs from standard sources and previous year question papers. While solving, always try to understand why an answer is correct, not just what it is. Revisit your weak areas through short quizzes, flashcards, or peer discussion. Regular revision and explanation-based learning will improve accuracy and confidence.

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