You will get here Chemistry Class 12 CBSE Notes and MCQs Chapter 8: Aldehydes, Ketones and Carboxylic Acids. You can connect with us for every important update related to class 12.
Chemistry is a very important subject for your board exam because it will help you increase your percentage and give big support in your entrance exam like JEE and NEET. You can score high marks in this subject by studying notes and practicing MCQs. In this post, we will cover Chapter 2: Aldehydes, Ketones and Carboxylic Acids .
Key Content Of Chapter 8 Aldehydes, Ketones and Carboxylic Acids
🔹 Basic Idea (Carbonyl Compounds) 🔹 Aldehydes (Definition) 🔹 Ketones (Definition) 🔹 Carboxylic Acids (Definition) ⭐ Nomenclature ⭐ Structure of Carbonyl Group ⭐ Preparation of Aldehydes & Ketones ⭐ Physical Properties ⭐ Chemical Reactions of Aldehydes & Ketones ⭐ Uses of Aldehydes & Ketones ⭐ Carboxylic Acids ⭐ Uses of Carboxylic Acids
Class 12 Chemistry Chapter 8: Aldehydes, Ketones and Carboxylic Acids Notes
CBSE Class 12 Chemistry – Unit 8
Aldehydes, Ketones and Carboxylic Acids
Complete Class 12 Chemistry Unit 8 (Aldehydes, Ketones and Carboxylic Acids)
ke detailed notes, syllabus, NCERT book PDF aur official Telegram channel
ka direct access yahan se milega. Isme carbonyl group, nomenclature,
preparation methods, physical & chemical properties, nucleophilic addition
reactions, aldol condensation, Cannizzaro reaction, acidity of carboxylic acids
aur industrial uses cover hai.
Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids MCQs
Q1. Carbonyl group present in aldehydes and ketones is:
A. >C=O
B. –OH
C. –COOH
D. –NH₂
✅ Correct Answer: >C=O
Q2. In aldehydes, carbonyl carbon is attached to:
A. One hydrogen and one carbon
B. Two hydrogen atoms
C. Two carbon atoms
D. Nitrogen atom
✅ Correct Answer: One hydrogen and one carbon
Q3. Functional group of carboxylic acids is:
A. –CHO
B. >C=O
C. –COOH
D. –OH
✅ Correct Answer: –COOH
Q4. Carbonyl carbon is:
A. Electrophilic
B. Nucleophilic
C. Neutral
D. Non-polar
✅ Correct Answer: Electrophilic
Q5. Hybridisation of carbonyl carbon is:
A. sp²
B. sp³
C. sp
D. dsp²
✅ Correct Answer: sp²
Q6. Aldehydes are generally more reactive than ketones due to:
A. Less steric hindrance
B. Higher boiling point
C. Hydrogen bonding
D. Non-polar nature
✅ Correct Answer: Less steric hindrance
Q7. Which reagent gives silver mirror test?
A. Tollens’ reagent
B. Fehling solution
C. NaOH
D. HCl
✅ Correct Answer: Tollens’ reagent
Q8. Aldol condensation occurs due to presence of:
A. α-hydrogen
B. Oxygen
C. Nitrogen
D. Double bond
✅ Correct Answer: α-hydrogen
Q9. Carboxylic acids are more acidic than alcohols due to:
A. Resonance stabilisation of carboxylate ion
B. Higher molecular mass
C. Low boiling point
D. Weak O–H bond
✅ Correct Answer: Resonance stabilisation of carboxylate ion
Q10. Which compound is commonly used as solvent?
A. Acetone
B. Methane
C. Benzene
D. Ethane
✅ Correct Answer: Acetone
Chemistry Chapter 8 Aldehydes, Ketones and Carboxylic Acids Quick Revision
🔹 Aldehydes (Definition) Aldehydes wo organic compounds hote hain jisme carbonyl group (–CHO) terminal carbon par attached hota hai. General formula → R–CHO.
🔹 Ketones (Definition) Ketones me carbonyl group (>C=O) do carbon atoms ke beech attached hota hai. General formula → R–CO–R′.
🔹 Carboxylic Acids (Definition) Carboxylic acids me –COOH functional group present hota hai jo carbonyl + hydroxyl group ka combination hota hai. General formula → R–COOH.
⭐ Nomenclature
Aldehydes → alkane se –al lagate hain (ethanal).
Ketones → alkane se –one lagate hain (propanone).
Carboxylic acids → alkane se –oic acid lagate hain (ethanoic acid).
Carbonyl group ko lowest number diya jata hai.
⭐ Structure of Carbonyl Group
Carbonyl group → >C=O.
Carbon sp² hybridised hota hai.
Structure trigonal planar (120°).
Bond polar hota hai → carbon electrophilic, oxygen nucleophilic.
Resonance stability present hoti hai.
⭐ Preparation of Aldehydes & Ketones
Primary alcohol oxidation → aldehyde.
Secondary alcohol oxidation → ketone.
Ozonolysis of alkenes.
Hydration of alkynes.
Friedel–Crafts acylation → ketones.
⭐ Physical Properties
Polar compounds hote hain.
Boiling point hydrocarbons se zyada, alcohols se kam.
Lower members water me soluble.
Dipole–dipole interaction show karte hain.
Lower aldehydes pungent smell rakhte hain.
⭐ Chemical Reactions of Aldehydes & Ketones
✅ Nucleophilic Addition Reaction Nucleophile carbonyl carbon par attack karta hai → addition product.
FAQs About Chapter Aldehydes, Ketones and Carboxylic Acids
⭐ Unit 8 – Aldehydes, Ketones and Carboxylic Acids FAQs
What are aldehydes?
Aldehydes organic compounds hote hain jisme carbonyl group (–CHO) present hota hai. Isme carbonyl carbon ek hydrogen aur ek carbon atom se attached hota hai.
What are ketones?
Ketones carbonyl compounds hote hain jisme carbonyl group (>C=O) do carbon atoms se attached hota hai. Example: Acetone.
What are carboxylic acids?
Carboxylic acids me carboxyl group (–COOH) present hota hai jo carbonyl group aur hydroxyl group ka combination hota hai. Ye acidic nature show karte hain.
What is carbonyl group?
Carbonyl group (>C=O) ek important functional group hai jisme carbon oxygen se double bond se attached hota hai. Carbon electrophilic aur oxygen nucleophilic hota hai.
Why are aldehydes more reactive than ketones?
Aldehydes me steric hindrance kam hoti hai aur sirf ek alkyl group hota hai, isliye nucleophilic addition reactions me ketones se zyada reactive hote hain.
What is nucleophilic addition reaction?
Is reaction me nucleophile carbonyl carbon par attack karta hai aur carbonyl group par addition product form hota hai. Ye aldehydes aur ketones ki important reaction hai.
What is aldol condensation?
Aldehydes ya ketones jisme α-hydrogen present ho, dilute base ki presence me β-hydroxy compound banate hain jise aldol condensation kehte hain.
Why are carboxylic acids acidic?
Carboxylic acids acidic hote hain kyunki carboxylate ion resonance se stabilised hota hai, jisse proton easily release hota hai.
How are aldehydes and ketones prepared?
Aldehydes aur ketones primary aur secondary alcohols ke oxidation, ozonolysis of alkenes, hydration of alkynes aur reduction reactions se prepare kiye jaate hain.
What are uses of aldehydes, ketones and carboxylic acids?
Aldehydes perfumes aur preservatives me use hote hain, ketones solvents ke roop me use hote hain aur carboxylic acids food industry, polymers aur medicines me use hote hain.
1 thought on “CBSE Class 12 Chemistry Chapter 8: Aldehydes, Ketones and Carboxylic Acids – Notes + MCQs | Quick Revision”