Aldehydes, Ketones & Carboxylic Acids – JEE Main PYQs Guide

Organic Chemistry plays a vital role in JEE Main, and the chapter Aldehydes, Ketones, and Carboxylic Acids is one of the most scoring units. Almost every year, JEE Main asks direct or concept-based questions from this chapter, mainly focusing on reactions, reagents, comparison of reactivity, and acidity order.

Why This Chapter is Important for JEE Main

This chapter tests a student’s understanding of carbonyl compounds and their chemical behavior. Questions are usually NCERT-based and involve:

• Reaction outcome identification
• Named reactions and reagents
• Reactivity comparison between compounds
• Acidity order of carboxylic acids
• Qualitative tests

Aldehydes – Important PYQ Areas

Aldehydes are more reactive than ketones due to less steric hindrance and greater electrophilicity of the carbonyl carbon.

Frequently Asked Topics

• Nucleophilic addition reactions (HCN, NaHSO₃, Grignard reagent)
• Oxidation of aldehydes to carboxylic acids
• Cannizzaro reaction (aldehydes without α-hydrogen)
• Aldol condensation
• Qualitative tests – Tollens’ test and Fehling’s test

Ketones – Important PYQ Areas

Ketones are less reactive than aldehydes but are still important for elimination-based and reaction-identification questions.

Frequently Asked Topics

• Reduction of ketones to secondary alcohols
• Aldol condensation (only when α-hydrogen is present)
• Resistance to oxidation under mild conditions
• Absence of Tollens’ and Fehling’s tests

Carboxylic Acids – Important PYQ Areas

Carboxylic acids are mainly tested for their acidic nature and preparation methods.

Frequently Asked Topics

• Acidity comparison and substituent effects
• Ortho effect in aromatic carboxylic acids
• Preparation from oxidation, nitriles, and esters
• Formation of acid derivatives
• Hell–Volhard–Zelinsky (HVZ) reaction

Important PYQ Trends in JEE Main

• Product prediction based on reagents
• Reactivity order: Aldehydes > Ketones
• Increasing or decreasing acidity order
• Statement-based questions on named reactions

How to Prepare This Chapter Using PYQs

• Read NCERT thoroughly, including exceptions
• Make short notes of reactions and tests
• Practice previous 10–15 years JEE Main questions
• Focus on concepts rather than memorization
• Revise reactions and acidity trends before the exam

Conclusion

Aldehydes, Ketones, and Carboxylic Acids is a high-return chapter for JEE Main. With strong NCERT fundamentals and regular PYQ practice, students can confidently score full marks from this unit. Revise smartly, practice regularly, and focus on reaction logic.