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Class 12 Aldehydes, Ketones, and Carboxylic Acids Solutions: Preparation for the board exam or a competitive entrance test requires good study materials, dedication, and discipline. Additionally, good conceptual knowledge of the topics is the key to success. Students who have mastered the concepts and exercises problems can not be stopped from scoring good marks in the test. Class 12 Chemistry Chapter 8 Aldehydes, Ketones, and Carboxylic Acids is an important chapter in organic chemistry. Topics such as Nomenclature, Preparation, Physical and Chemical Properties, Reactions, and Mechanisms related to aldehydes, ketones and carboxylic acids are covered in Class 12 Chemistry Chapter 8 syllabus.
Students looking for the intext questions and exercise solutions can refer to the NCERT Solutions for Class 12 Chemistry Chapter 8 Aldehydes, Ketones, and Carboxylic Acids provided by Shiksha. Our expert educators at Shiksha have prepared the NCERT Class 12 Chemistry solutions based on the latest CBSE Class 12 syllabus and guidelines. The aim of providing the Class 12 Chemistry Aldehydes, Ketones, and Carboxylic Acids NCERT Solutions pdf is to help the students in understanding the concepts and performing well in the board exams.
Our NCERT solutions break down complex reaction mechanisms and provide step-by-step explanations to help you build a solid foundation in organic chemistry and improve your problem-solving skills. Students can download the free pdf of NCERT solution for Class 12 Aldehydes, Ketones, and Carboxylic Acids online. The link to download the Aldehydes, Ketones, and Carboxylic Acid NCERT solutions pdf is activated in this article.
Many competitive exams, like NEET and JEE, test understanding of reaction mechanisms like Aldol Condensation, Cannizzaro Reaction, Kolbe’s Electrolysis and Decarboxylation Reactions. Moreover, in the class 12 board exam, questions are based on nucleophilic addition reactions, electrophilic substitution in carboxylic acids, and applications of aldehydes and ketones in synthesis.
Additionally, students must prepare Aldehydes, Ketones and Carboxylic Acids class 12 notes pdf while studying. Mention important topics, formulas, and definitions in the handy notes for quick revision while preparing for the test. Students can also check the NCERT solutions for Class 11 Chemistry provided by Shiksha, designed with the help of our experts.
Note:- As per the latest CBSE 2025 Syllabus, No topic has been added or deleted from the Chapter 8 Aldehydes, Ketones, and Carboxylic Acids of NCERT Class 12 Chemistry. This chapter is renumbered as chapter 8 in the latest CBSE syllabus.
- Important Topics and Reactions in NCERT Chemistry Class 12 Aldehyde, Ketones and Carboxylic Acids
- NCERT Chemistry Class 12th Solution PDF - Aldehyde, Ketones and Carboxylic Acids Chapter Download
- NCERT Solutions for Class 12 Chemistry Aldehyde, Ketones and Carboxylic Acids
- Advantage of using NCERT Solutions for Class 12 Chemistry Chapter 8
Important Topics and Reactions in NCERT Chemistry Class 12 Aldehyde, Ketones and Carboxylic Acids
Students will also need important chapter topics, concepts, and reactions to prepare accordingly and perform well in the exams. Along with Class 12 Chemistry Ch 8 NCERT Solutions, we have provided list of topics covered in the chapter, and important reactions. Students can check the list below and take help from the information to boost their preparation level.
Important Topics covered in Class 12 Chemistry Chapter 8: Aldehydes, Ketones, and Carboxylic Acids
- Nomenclature and Structure of Carbonyl Group
- Preparation of Aldehydes and Ketones
- Physical Properties
- Chemical Reactions
- Uses of Aldehydes and Ketones
- Nomenclature and Structure of Carboxyl Group
- Methods of Preparation of Carboxylic Acids
- Physical Properties
- Chemical Reactions
- Uses of Carboxylic Acids
Important Reactions of NCERT Class 12 Chemistry Aldehydes, Ketones, and Carboxylic Acids
1. Preparation Reactions
From Alcohols (Oxidation Reaction)
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Primary Alcohol : R-CH₂OH + [O] R-CHO + H₂O
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Secondary Alcohol : R-CHOH-R' + [O] R-CO-R' + H₂O
From Hydrocarbons
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Ozonolysis of Alkenes:
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R-CH=CH-R' + O₃ R-CHO + R'-CHO
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Friedel-Crafts Acylation:
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Benzene + RCOCl + AlCl₃ Acetophenone
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From Carboxylic Acids & Their Derivatives
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Reduction of Carboxylic Acid:
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RCOOH + LiAlH₄ RCH₂OH
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Rosenmund Reduction:
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RCOCl + H₂/Pd + BaSO₄ RCHO
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2. Reactions of Aldehydes & Ketones
Nucleophilic Addition Reactions
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Addition of HCN: R-CHO + HCN R-CH(OH)-CN
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Addition of Alcohols: R-CHO + ROH (Hemiacetal Acetal)
Oxidation Reactions
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Aldehyde : R-CHO + [O] RCOOH
Reduction Reactions
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Aldehydes & Ketones Alcohols (Reduction by LiAlH₄/NaBH₄):
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R-CHO + H₂ R-CH₂OH
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R-CO-R' + H₂ R-CHOH-R'
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Clemmensen Reduction (Zn-Hg/HCl):
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R-CO-R' R-CH₂-R'
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Wolff-Kishner Reduction (NH₂NH₂/KOH):
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R-CO-R' R-CH₂-R'
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Haloform Reaction (Test for Methyl Ketones & Acetaldehyde)
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CH₃CO-R + I₂ + NaOH CHI₃ (Yellow ppt) + RCOONa
Tollen’s Test (Silver Mirror Test – for Aldehydes Only)
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R-CHO + Ag⁺ + NH₃ + H₂O RCOO⁻ + Ag↓ (Silver Mirror)
Fehling’s Test (For Aldehydes, Not Ketones)
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R-CHO + Fehling’s Solution Red Precipitate of Cu₂O
3. Reactions of Carboxylic Acids
Acidic Nature
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RCOOH + NaOH RCOO⁻Na⁺ + H₂O
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RCOOH + NaHCO₃ RCOO⁻Na⁺ + CO₂ + H₂O
Reduction
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RCOOH + LiAlH₄ RCH₂OH
Decarboxylation Reaction
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RCOOH + NaOH + CaO RH + Na₂CO₃
Hell-Volhard-Zelinsky (HVZ) Reaction
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RCH₂COOH + Br₂ RCHBrCOOH
Esterification (Reaction with Alcohols)
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RCOOH + ROH RCOOR + H₂O
- Amide Formation (Reaction with Ammonia)
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RCOOH + NH₃ RCONH₂
NCERT Chemistry Class 12th Solution PDF - Aldehyde, Ketones and Carboxylic Acids Chapter Download
Candidates can check here NCERT Class 12 Chemistry Aldehyde, Ketone, and Carboxylic Acids solutions provided by subject experts in an easy-to-understand language. Students can access and download Class 12 Chemistry Ch 8 Aldehyde, Ketone and Carboxylic Acids NCERT Solutions to study offline and practice ncert exercise questions. The link to download the NCERT Solution PDF is given below;
Class 12 Chemistry Aldehyde ketone and Carboxylic Acid NCERT Solutions PDF: Free PDF Download
NCERT Solutions for Class 12 Chemistry Aldehyde, Ketones and Carboxylic Acids
Students can find the Class 12 Chapter 8 Aldehydes, Ketones, and Carboxylic Acids intext solutions below. The solutions are explained in an easy way for better understanding. Intext questions are concept-based.
| Q12.1 Write the structures of the following compounds. (i) α-Methoxypropionaldehyde (ii) 3-Hydroxybutanal (iii) 2-Hydroxycyclopentane carbaldehyde (iv) 4-Oxopentanal (v) Di-sec. butyl ketone (vi) 4-Fluoroacetophenone |
| Ans (i) The compound contains ether group and an aldehydic functional group with the longest chain having 3 carbon atoms. α means the position of the carbon atom attached to attached to the carbon atom of the functional group, in this case, it is an aldehyde functional group. (ii) The compound contains an alcoholic group and an aldehydic functional group with the longest chain having 4 carbon The numbering of the chain starts from a carbon atom of aldehyde group. (iii) The compound contains an alcoholic group and an aldehydic functional group, with the longest chain having 5 carbon atoms, which are cyclic in The numbering of the chain starts from a carbon atom of the aldehyde group attached to the cyclopentane ring. (iv) The compound contains ketone group and an aldehydic functional group with the longest chain having 5 carbon The numbering of the chain starts from a carbon atom of aldehyde group. (v) The compound contains ketone functional group with the longest chain having 8(butyl is used because there is two similar butyl group attached to the carbonyl carbon of ketone group) carbon (vi) The compound contains a fluorine atom and a ketone functional group with the longest chain which is a derivative of a phenyl group and an acetyl substituent. |
| Q 12.2 Write the structures of products of the following reactions |
| Ans |
| Q 12.3 Arrange the following compounds in increasing order of their boiling points. CH3 CHO, CH3 CH2OH, CH3OCH3 , CH3 CH2 CH3 |
| Ans The molecular masses of the given compounds are in the range of 44-66 g/mol. The second molecule, CH3CH2OH contains OH alcoholic group due to which it undergoes extensive H bonding with each other molecules, leading to the association of the molecules. Therefore, it has the highest boiling point. In the molecule CH3CHO , there is strong intermolecular dipole-dipole attraction due to presence of - CHO aldehydic group( as H will have partial positive charge and oxygen will have partial negative charge, so there will attraction between molecules), which is weak in case of CH3OCH3 as both CH3 groups have +I effect which results in decrease in electron affinity for the oxygen attached to it( with no partially positive H atom). And in CH3CH2CH3, there are only weak van der Waals forces of attraction. So the compounds in increasing order of their boiling point are: CH3CH2CH3< CH3OCH3< CH3CHO< CH3CH2OH. |
| Q 12.4 Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions. (i) Ethanal, Propanal, Propanone, Butanone. (ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone. |
| Ans (i) Ethanal, Propanal, Propanone, Butanone The +I effect increases in the order as: Ethanal
Therefore, the electron density of the carbonyl carbon increases as the +I effect due to the alkyl group increases. As a result, the chances of attack by a nucleophile (which are rich in electrons and carry a negative charge, not necessarily usually have a lone pair of an electrons) decrease because the carbonyl carbon has electron density on it. Hence, the increasing order of the reactivity of the given compounds in nucleophilic addition reaction is: Ethanal > Propanal> Propanone > Butanone. (ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone: The +I effect is more in ketone than in aldehyde because in ketone, there are 2 alkyl groups contributing in the +I effect whereas in aldehydes, there is only one alkyl group. Hence, acetophenone(being a ketone group attached to it) is the least reactive in nucleophilic addition reactions. Among aldehydes, the +I effect is the highest in p-tolualdehyde because of the presence of the electron- donating –CH3 group(which increase the electron density on the carbonyl carbon via resonance through the benzene ring) and the lowest in p-nitrobenzaldehyde because of the presence of the electron- withdrawing –NO2 group(which decreases the electron density on the carbonyl carbon via resonance through the benzene ring). Hence, the increasing order of the reactivity of the given compounds is: Acetophenone<p-tolualdehyde
|
Commonly asked questions
Give plausible explanation for each of the following:
(i) Cyclohexanone forms cyanohydrin in good yield but 2,2,6-trimethylcyclohexanone does not.
(ii) There are two –NH2 groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
(iii) During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.
Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?
Write the structures of the following compounds.
(i) α-Methoxypropionaldehyde
(ii) 3-Hydroxybutanal
(iii) 2-Hydroxycyclopentane carbaldehyde
(iv) 4-Oxopentanal
(v) Di-sec. butyl ketone
(vi) 4-Fluoroacetophenone
What is meant by the following terms? Give an example of the reaction in each case.
(i) Cyanohydrin
(ii) Acetal
(iii) Semicarbazone
(iv) Aldol
(v) Hemiacetal
(vi) Oxime
(vii) Ketal
(vii) Imine
(ix) 2,4-DNP-derivative
(x) Schiff’s base
Write the structures of products of the following reactions
Arrange the following compounds in increasing order of their boiling points. CH3 CHO, CH3 CH2OH, CH3OCH3 , CH3 CH2 CH3
Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
(i) Ethanal, Propanal, Propanone, Butanone.
(ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Predict the products of the following reactions:
Give the IUPAC names of the following compounds:
Show how each of the following compounds can be converted to benzoic acid.
(i) Ethylbenzene
(ii) Acetophenone
(iii) Bromobenzene
(iv) Phenylethene (Styrene)
Which acid of each pair shown here would you expect to be stronger?
(i) CH3CO2H or CH2FCO2H
(ii) CH2FCO2H or CH2ClCO2H
(iii) CH2 FCH2 CH2 CO2H or CH3 CHFCH2 CO2H
Name the following compounds according to IUPAC system of nomenclature:
(i) CH3CH(CH3 )CH2CH2CHO
(ii) CH3CH2COCH(C2H5 )CH2CH2Cl
(iii) CH3CH=CHCHO
(iv) CH3COCH2COCH3
(v) CH3CH(CH3 )CH2C(CH3 )2COCH3
(vi) (CH3 )3CCH2COOH
(vii) OHCC6H4CHO-p
Draw the structures of the following compounds.
(i) 3-Methylbutanal
(ii) p-Nitropropiophenone
(iii) p-Methylbenzaldehyde
(iv) 4-Methylpent-3-en-2-one
(v) 4-Chloropentan-2-one
(vi) 3-Bromo-4-phenylpentanoic acid
(vii) p,p’-Dihydroxybenzophenone
(viii) Hex-2-en-4-ynoic acid
Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names.
(i) CH3CO(CH2 )4CH3
(ii) CH3CH2CHBrCH2CH(CH3 )CHO
(iii) CH3 (CH2 )5CHO
(iv) Ph-CH=CH-CHO
(v) 
(vi) PhCOPh
Draw structures of the following derivatives.
(i) The 2,4-dinitrophenylhydrazone of benzaldehyde
(ii) Cyclopropanone oxime
(iii) Acetaldehydedimethylacetal
(iv) The semicarbazone of cyclobutanone
(v) The ethylene ketal of hexan-3-one
(vi) The methyl hemiacetal of formaldehyde
Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents.
(i) PhMgBr and then H3O+
(ii) Tollens’ reagent
(iii) Semicarbazide and weak acid
(iv) Excess ethanol and acid
(v) Zinc amalgam and dilute hydrochloric acid
Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.
(i) Methanal
(ii) 2-Methylpentanal
(iii) Benzaldehyde
(iv) Benzophenone
(v) Cyclohexanone
(vi) 1-Phenylpropanone
(vii) Phenylacetaldehyde
(viii) Butan-1-ol
(ix) 2,2-Dimethylbutanal
How will you convert ethanal into the following compounds?
(i) Butane-1,3-diol
(ii) But-2-enal
(iii) But-2-enoic acid
Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.
An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.
An organic compound (A) (Molecular formula C8H16O2) was hydrolysed with dilute sulphuric acid to give a carboxylic acid (B) And an alcohol (C). Oxidation of (C) with chromic acid produced (B). (C) On dehydration gives but-1-ene. Write equations for the reactions involved.(Intermediate)
Arrange the following compounds in increasing order of their property as indicated:
(i) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
(ii) CH3CH2CH(Br)COOH, CH3CH(Br)CH2COOH, (CH3)2CHCOOH, CH3CH2CH2COOH (acid strength)
(iii) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
Give simple chemical tests to distinguish between the following pairs of compounds.
(i) Propanal and Propanone
(ii) Acetophenone and Benzophenone
(iii) Phenol and Benzoic acid
(iv) Benzoic acid and Ethyl benzoate
(v) Pentan-2-one and Pentan-3-one
(vi) Benzaldehyde and Acetophenone
(vii) Ethanal and Propanal
How will you prepare the following compounds from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom
(i) Methyl benzoate
(ii) m-Nitrobenzoic acid
(iii) p-Nitrobenzoic acid
(iv) Phenylacetic acid
(v) p-Nitrobenzaldehyde.
How will you bring about the following conversions in not more than two steps?
(i) Propanone to Propene
(ii) Benzoic acid to Benzaldehyde
(iii) Ethanol to 3-Hydroxybutanal
(iv) Benzene to m-Nitroacetophenone
(v) Benzaldehyde to Benzophenone
(vi) Bromobenzene to 1-Phenylethanol
(vii) Benzaldehyde to 3-Phenylpropan-1-ol
(viii) Benazaldehyde to α-Hydroxyphenylacetic acid
(ix) Benzoic acid to m- Nitrobenzyl alcohol
Describe the following:
(i) Acetylation
(ii) Cannizzaro reaction
(iii) Cross aldol condensation
(iv) Decarboxylation
Complete each synthesis by giving missing starting material, reagent or products
An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound.
Advantage of using NCERT Solutions for Class 12 Chemistry Chapter 8
The benefit of using the Aldehyde, Ketones and Carboxylic Acids ncert solutions are as follows:
- Basic concepts are clear
- Improve problem-solving skills
- Familiarise with the most important topics or high-weightage topics
- Good resource for practice and revision
- Boost confidence in students
Chemistry Ncert Solutions Class 12th Exam
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