India's #1 AI Tutorworksheet · Chemistry · Chapter 8

CBSE Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids Worksheet with Answers

Aldehydes, Ketones and Carboxylic Acids form a crucial chapter in CBSE Class 12 Chemistry, typically carrying 6-8 marks in the board examination. Mastering nomenclature, preparation methods and reaction mechanisms is essential not only for scoring high marks but also for competitive exams like JEE and NEET. This comprehensive worksheet provides structured practice across all question types — from objective MCQs to higher-order thinking problems. Print this worksheet, set a timer for 90 minutes, and attempt all sections without referring to your notes to gauge your true exam readiness.

Your child's private AI tutor — trained on NCERT.

3-day free trial · ₹1 to start · Cancel anytime.

Start 3-day free trial →

Key takeaways

✓This worksheet covers all topics from CBSE Class 12 Chemistry Chapter 8: nomenclature, preparation, reactions and mechanisms of aldehydes, ketones and carboxylic acids.
✓Difficulty level is moderate-to-challenging with suggested completion time of 90 minutes to simulate board exam conditions.
✓Section A contains 6 MCQs testing fundamental concepts, while Section E has 3 HOTS questions demanding deeper understanding of reaction mechanisms.
✓The case-study question integrates real-world applications of carbonyl compounds in pharmaceuticals and industry.
✓Complete answer key with brief explanations enables self-assessment and identifies gaps in understanding before the board exam.
✓Questions follow the latest CBSE marking scheme pattern with 1-mark, 2-mark, 3-mark and 5-mark distribution.
✓All terminology and reaction mechanisms are sourced directly from the NCERT Class 12 Chemistry textbook to ensure accuracy.

Chapter Overview and Key Concepts Recap

Before attempting the worksheet, quickly review the essential concepts from Chapter 8. Aldehydes and ketones both contain the carbonyl group (C=O), with aldehydes having at least one hydrogen attached to the carbonyl carbon (R-CHO) and ketones having two alkyl or aryl groups (R-CO-R'). Carboxylic acids contain the carboxyl group (-COOH). Understanding the nomenclature rules as per IUPAC is fundamental — aldehydes use the suffix '-al', ketones use '-one', and carboxylic acids use '-oic acid'. The chapter extensively covers preparation methods including oxidation of alcohols, ozonolysis of alkenes, and hydrolysis of nitriles. Chemical reactions such as nucleophilic addition, oxidation, reduction, and esterification are critical. Reaction mechanisms, particularly the nucleophilic addition mechanism in aldehydes and ketones, appear frequently in board exams. The 2024 CBSE Chemistry paper allocated 5 marks to this chapter across one short-answer and one long-answer question.

Aldehydes are more reactive than ketones due to steric and electronic factors affecting the carbonyl carbon.
Common reagents: Tollen's reagent and Fehling's solution distinguish aldehydes from ketones through oxidation reactions.
Cannizzaro reaction occurs with aldehydes lacking alpha-hydrogen atoms when treated with concentrated alkali.
Hell-Volhard-Zelinsky (HVZ) reaction introduces halogen at alpha-position of carboxylic acids using red phosphorus and halogen.
Rosenmund reduction converts acid chlorides to aldehydes using palladium catalyst poisoned with barium sulfate.
Clemmensen reduction (Zn-Hg/HCl) and Wolf-Kishner reduction (NH₂-NH₂/KOH) convert carbonyl compounds to alkanes.

Worksheet Details: Difficulty Level and Time Allocation

This worksheet is designed at a moderate-to-challenging difficulty level, mirroring the standard of questions that appear in CBSE Class 12 board examinations and various state-level assessments. The suggested time for completion is 90 minutes, which allows approximately 1 minute per MCQ, 2 minutes per fill-in-the-blank or matching question, 4-5 minutes per short-answer question, 10-12 minutes per long-answer question, and 8 minutes for the case study. Students should attempt this worksheet in one sitting under timed conditions to build exam temperament and speed. The distribution of marks mirrors the CBSE pattern: Section A (6 marks), Section B (5 marks), Section C (4 marks), Section D (10 marks), Section E (15 marks), and the case study (5 marks), totaling 45 marks. This comprehensive assessment covers all subtopics from nomenclature through complex reaction mechanisms, ensuring thorough revision. After completion, use the detailed answer key to score yourself honestly and identify weak areas that need focused revision.

Total marks: 45 | Total time: 90 minutes
Difficulty: Moderate-to-Challenging (aligned with CBSE board standard)
Sections A-C test foundational recall and application (15 marks)
Sections D-E demand analytical thinking and mechanism writing (25 marks)
Case study integrates conceptual understanding with real-world context (5 marks)
Recommended for students who have completed at least one full chapter reading from NCERT

Section A: Multiple Choice Questions (6 Questions × 1 Mark Each)

This section contains six carefully curated MCQs covering fundamental concepts, nomenclature, and key reactions from Chapter 8. Each question has four options with only one correct answer. These questions test your ability to recall IUPAC naming conventions, identify correct reagents for specific transformations, and understand the reactivity differences between aldehydes, ketones, and carboxylic acids. MCQs often appear in the board exam as 1-mark questions and are also critical for competitive exams. Read each question carefully, eliminate obviously incorrect options, and choose the most precise answer. Do not spend more than one minute per question in this section.

Section B: Fill in the Blanks (5 Questions × 1 Mark Each)

Section B comprises five fill-in-the-blank questions designed to test precise terminology and factual recall from the chapter. These questions require you to remember specific reagents, product names, reaction conditions, and important observations. Write concise, accurate answers — spelling matters, especially for chemical names and reagents. This section evaluates your grasp of chapter vocabulary and your ability to recall specific details that are often tested in board examinations. Fill-in-the-blank questions typically appear in the 1-mark category and require exact answers, so revise nomenclature rules and standard reagent names thoroughly before attempting.

Section C: Match the Following and Assertion-Reason (4 Marks)

Section C tests your ability to correlate reactions with their reagents and evaluate the logical connection between assertion and reasoning statements. Part I requires you to match four reactions or compounds in Column A with the appropriate reagents or products in Column B. Part II presents an assertion-reason question where you must decide whether both statements are true and if the reason correctly explains the assertion. This question type appeared in the 2023 and 2024 CBSE Chemistry papers and requires careful reading. For matching questions, first identify the obvious pairs, then use elimination for the remaining ones. For assertion-reason, evaluate each statement independently before judging the relationship between them.

Section D: Short Answer Questions (5 Questions × 2 Marks Each)

Section D contains five short-answer questions, each carrying 2 marks. These questions require brief but complete answers, typically 2-3 sentences or a short reaction sequence with conditions. You may be asked to write a single reaction with reagents, explain a specific observation, differentiate between two compounds using a chemical test, or describe a property or mechanism in brief. According to the CBSE marking scheme, 2-mark questions reward clarity and completeness — mention the reagent, conditions, and product for reactions, or provide two distinct points for explanatory questions. Avoid writing long paragraphs; use point form where appropriate. Practice writing crisp, precise answers that directly address what the question asks.

Section E: Long Answer and HOTS Questions (3 Questions)

Section E challenges you with three long-answer or higher-order thinking questions, each worth 5 marks. These questions demand detailed explanations, multi-step reaction sequences, complete mechanism illustrations, or comparative analyses. A typical 5-mark question may ask you to explain a reaction mechanism with all intermediate steps, convert one compound to another through a multi-step synthesis, or discuss the chemical behavior of a class of compounds with supporting reactions. According to CBSE guidelines, 5-mark answers should be well-structured with clear subheadings or numbered points. For mechanism questions, draw all resonance structures, show electron movement with curved arrows, and label intermediates. For conversion problems, write each step separately with reagents and conditions. Allocate 10-12 minutes per question and ensure you cover all aspects asked.

Case-Study Based Question (5 Marks)

Case-study questions integrate theoretical knowledge with real-world applications, a format introduced by CBSE to test analytical and application skills. The case study presents a paragraph describing an industrial process, pharmaceutical application, or everyday phenomenon involving aldehydes, ketones, or carboxylic acids, followed by 4-5 sub-questions. Read the passage carefully and underline key information before attempting the questions. Sub-questions may be MCQs, one-word answers, or short explanations worth 1 mark each. The 2024 CBSE Chemistry paper featured a case study on formaldehyde in disinfectants and resins. This section rewards students who can connect classroom chemistry to practical contexts. Allocate 8 minutes for reading the case and answering all sub-questions. Answers should reference the passage where applicable.

Complete Answer Key with Explanations

This comprehensive answer key provides correct answers along with brief explanations for every question in the worksheet. Use this section to self-assess your performance after completing the worksheet. Award yourself marks honestly according to the CBSE marking scheme: full marks for completely correct answers, partial marks for answers that are correct but incomplete, and zero for incorrect answers. For mechanism and conversion questions, check that you have included all intermediate steps and reagents. The explanations clarify why a particular answer is correct and highlight common mistakes students make. If you score below 70 percent in any section, revisit those topics in your NCERT Class 12 Chemistry textbook and make notes. Regular practice with such worksheets, combined with NCERT solutions and concept clarity, is the proven formula for scoring above 90 in the CBSE Chemistry board exam.

Section A MCQs carry 1 mark each; no negative marking, so attempt all questions even if unsure.
For short answers (Section D), award 1 mark for correct reaction and 1 mark for correct reagents/conditions.
Long answers (Section E) have distributed marking: mechanism steps, structures, and explanations each carry partial marks.
Case-study sub-questions are usually direct; answers must be drawn from the passage or applied knowledge.
Common errors: wrong IUPAC names (forgetting numbering direction), incomplete mechanisms (missing curved arrows), omitting reaction conditions.

How CBSETUTOR.ai Supports Mastery of Chapter 8

Achieving mastery in Aldehydes, Ketones and Carboxylic Acids requires consistent practice, conceptual clarity, and the ability to solve diverse problem types under timed conditions. CBSETUTOR.ai provides a 24×7 AI tutor that allows Class 12 students to upload photos of tricky reaction mechanisms, complex conversion problems, or case-study questions and receive instant step-by-step solutions. Whether you are stuck on the Cannizzaro reaction mechanism at 11 PM the night before your exam or need five more practice questions on nomenclature, the platform delivers personalized support tailored to your learning pace. Unlike traditional coaching that operates on fixed schedules, CBSETUTOR.ai is available round-the-clock at a flat subscription of just ₹999 per month covering all subjects for classes 6 to 12. The platform identifies your weak areas in Chapter 8 through adaptive quizzes and recommends targeted practice, ensuring you do not waste time on topics you have already mastered. Thousands of students across India have reported score improvements of 15-20 marks in Chemistry after consistent use. Start your 3-day free trial today and experience how AI-powered learning transforms board exam preparation.

Upload images of NCERT problems or worksheet questions and get detailed solutions with reaction mechanisms illustrated.
Access an unlimited question bank for Chapter 8, sorted by difficulty and question type (MCQ, short answer, long answer).
Receive instant feedback on your answers, with explanations highlighting where you went wrong in naming or mechanism steps.
Practice timed mock tests exclusively on Aldehydes, Ketones and Carboxylic Acids to build speed and accuracy.
Flat ₹999/month for all subjects and classes 6-12; no hidden charges, no per-question fees.
3-day free trial allows you to explore all features before committing; cancel anytime if not satisfied.

Tips for Scoring Full Marks in Chapter 8 Questions

To maximize your score in Aldehydes, Ketones and Carboxylic Acids questions, follow a strategic approach. First, memorize all IUPAC nomenclature rules and practice naming at least 20 different structures until it becomes automatic. Second, create a reaction flowchart covering all preparation methods and chemical reactions; visual learners benefit immensely from such mind maps. Third, practice writing mechanisms with curved arrows showing electron movement — examiners award marks for clear depiction of intermediate steps. Fourth, maintain a separate notebook for named reactions (Rosenmund, Clemmensen, Wolf-Kishner, Cannizzaro, Aldol, HVZ) with one-line summaries and reagent conditions; revise this notebook daily in the final week before the exam. Fifth, solve at least five previous years' CBSE board questions from this chapter to understand the question pattern and frequently asked reactions. The 2023 board paper asked a 5-mark question on converting benzaldehyde to benzophenone, which required knowledge of Grignard reagent chemistry. Regular timed practice with worksheets like this one builds the stamina and confidence needed to complete the Chemistry paper in three hours without rushing.

Always write reagents and conditions above/below the reaction arrow; marks are deducted for omission in board exams.
For 'distinguish between' questions, mention both the reagent and the observable difference (color change, precipitate).
In mechanism questions, draw the intermediate structure separately and label it; do not skip steps.
When asked to convert compound X to Y, write each reaction in sequence rather than jumping directly to the product.
Revise functional group priority order for IUPAC naming: carboxylic acid > aldehyde > ketone > alcohol.
Practice writing structures from names and vice versa; this dual skill is tested in almost every board exam.

Frequently asked questions

What is the ideal time to complete this CBSE Class 12 Chemistry Chapter 8 worksheet?+

The suggested time is 90 minutes to complete all sections, mimicking board exam conditions. Section A should take about 6 minutes, Section B around 5 minutes, Section C about 6 minutes, Section D approximately 20 minutes, Section E around 35 minutes, and the case study about 8 minutes. This time allocation helps build exam speed and stamina essential for the 3-hour Chemistry board paper.

How many marks does Chapter 8 Aldehydes, Ketones and Carboxylic Acids typically carry in the CBSE Class 12 Chemistry board exam?+

Chapter 8 typically carries 6 to 8 marks in the CBSE Class 12 Chemistry board examination. Questions usually include one 2-mark short answer (e.g., distinguish between two compounds or write a specific reaction) and one 5-mark long answer (e.g., reaction mechanism, multi-step conversion, or a combination question). Occasionally, 1-mark MCQs from this chapter appear in the objective section introduced in recent board patterns.

Which named reactions from Chapter 8 are most important for the board exam?+

The most frequently examined named reactions are Rosenmund reduction (acid chloride to aldehyde), Clemmensen and Wolf-Kishner reductions (carbonyl to alkane), Cannizzaro reaction (disproportionation of aldehydes without alpha-H), Aldol condensation, Hell-Volhard-Zelinsky (HVZ) reaction (alpha-halogenation of acids), and Etard reaction (toluene to benzaldehyde). Memorize reagents, conditions, and products for each; they appear regularly in 2-mark and 5-mark questions.

What are common mistakes students make in mechanism questions for aldehydes and ketones?+

Common errors include: not showing the curved arrows to indicate electron movement, omitting the tetrahedral intermediate in nucleophilic addition, forgetting to protonate or deprotonate at the correct step, and writing incomplete structures without showing all lone pairs and charges. In aldol condensation, students often forget the dehydration step. For full marks, clearly draw each intermediate, label charges, and write 'protonation' or 'deprotonation' beside the relevant step.

How should I differentiate between an aldehyde and a ketone using chemical tests?+

Use Tollen's reagent (ammoniacal AgNO₃) or Fehling's solution. Aldehydes reduce Tollen's reagent to metallic silver, forming a silver mirror on the test tube wall, while ketones show no reaction. With Fehling's solution (alkaline copper complex), aldehydes produce a brick-red precipitate of Cu₂O, whereas ketones remain unreactive. Always mention the observation (color change or precipitate) for full 2 marks in differentiation questions.

Why are carboxylic acids more acidic than alcohols and phenols?+

Carboxylic acids are more acidic because the carboxylate ion (RCOO⁻) formed after losing a proton is stabilized by resonance, with the negative charge equally distributed over two oxygen atoms. In contrast, alkoxide ions (RO⁻) from alcohols have no resonance stabilization, and phenoxide ions have less effective resonance since the negative charge is spread over the benzene ring. Typical pKa: carboxylic acids 4-5, phenols 10, alcohols 15-16.

What is the importance of alpha-hydrogen in the reactions of aldehydes and ketones?+

Alpha-hydrogen (hydrogen on the carbon adjacent to the carbonyl group) is acidic and can be removed by a base, generating an enolate ion. This enolate participates in important reactions like aldol condensation, halogenation (haloform reaction), and alkylation. Aldehydes or ketones without alpha-hydrogen cannot undergo these reactions but may undergo Cannizzaro reaction instead. Understanding alpha-hydrogen reactivity is crucial for predicting reaction pathways.

How is this worksheet aligned with the latest CBSE syllabus and exam pattern?+

This worksheet strictly follows the 2024-25 CBSE Class 12 Chemistry syllabus for Chapter 8, covering nomenclature, preparation, reactions, and mechanisms as listed in the NCERT textbook. The question format mirrors the current board pattern: MCQs, fill-in-the-blanks, assertion-reason, short answers (2 marks), long answers (5 marks), and case-study questions. The difficulty level, mark distribution, and time allocation are designed to match actual board exam standards, ensuring authentic practice.

Should I memorize all the chemical structures and IUPAC names from Chapter 8?+

Yes, memorizing IUPAC nomenclature rules and being able to draw structures from names (and vice versa) is essential. Practice writing structures for aldehydes, ketones, and carboxylic acids with 3 to 6 carbon atoms, including branched chains. Questions worth 2-3 marks often ask you to name a given structure or draw the structure from a name. Create flashcards for common compounds like formaldehyde, acetaldehyde, acetone, benzaldehyde, benzoic acid, and their derivatives for quick recall.

Can CBSETUTOR.ai help me with personalized practice for weak topics in Chapter 8?+

Absolutely. CBSETUTOR.ai uses adaptive learning technology to identify your weak areas in Chapter 8 after you attempt diagnostic quizzes. If you struggle with, say, reaction mechanisms or nomenclature, the platform generates additional targeted practice questions on those specific subtopics. You can also upload photos of difficult questions from this or any other worksheet and receive step-by-step video or text solutions instantly. The 3-day free trial lets you explore these features risk-free before subscribing.

Related resources

Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids — Formulas & Key Points Important Questions: CBSE Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids CBSE Class 12 Chemistry Chapter 7 Alcohols, Phenols and Ethers Worksheet with Answers Class 12 Chemistry Chapter 7 Alcohols, Phenols and Ethers — Formulas & Key Points AI Tutor for Class 12: The Smart Alternative to Tuition AI Tutor for Class 12 Accountancy: Learn Faster with Instant Help Online Class 9 Chemistry Tutor in Mumbai — NCERT-Aligned Board Exam Coaching CBSE Class 9 Mathematics Chapter 1 Number Systems Worksheet with Answers

Keep learning — related guides

Class 12Chemistry

Class 12 Chemistry Tutor in Rushikonda, Visakhapatnam

Class 12Chemistry

Class 12 Chemistry Chapter 9 Amines — Formulas & Key Points

Class 12Chemistry

Class 12 Chemistry Chapter 10 Biomolecules — Formulas & Key Points

Class 12Chemistry

CBSE Class 12 Chemistry Chapter 10 Biomolecules Worksheet with Answers

Class 12Chemistry

Important Questions: CBSE Class 12 Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids

Class 12Chemistry

Important Questions: CBSE Class 12 Chemistry Chapter 7 Alcohols, Phenols and Ethers

Ready to give your Class 12 child the tutor that never sleeps?

CBSETUTOR.ai covers every chapter in the Class 12 NCERT syllabus — Maths, Science, Social Science, English, Hindi and more. 24×7. Patient. Unlimited. 3-day free trial.

Start your child's 3-day free trial →