NCERT Solutions | Class 12 Chemistry Chapter 12

NCERT Solutions | Class 12 Chemistry Chapter 12 | Aldehydes Ketones and Carboxylic Acids 

CBSE Solutions | Chemistry Class 12

Check the below NCERT Solutions for Class 12 Chemistry Chapter 12 Aldehydes Ketones and Carboxylic Acids Pdf free download. NCERT Solutions Class 12 Chemistry  were prepared based on the latest exam pattern. We have Provided Aldehydes Ketones and Carboxylic Acids Class 12 Chemistry NCERT Solutions to help students understand the concept very well.

NCERT | Class 12 Chemistry

NCERT Solutions Class 12 Chemistry

Book:	National Council of Educational Research and Training (NCERT)
Board:	Central Board of Secondary Education (CBSE)
Class:	12th
Subject:	Chemistry
Chapter:	12
Chapters Name:	Aldehydes Ketones and Carboxylic Acids
Medium:	English

Aldehydes Ketones and Carboxylic Acids | Class 12 Chemistry | NCERT Books Solutions

You can refer to MCQ Questions for Class 12 Chemistry Chapter 12 Aldehydes Ketones and Carboxylic Acids to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

NCERT Exercises

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 1.

Write the structures of the following compounds.

1. α-Methoxypropionaldehyde
2. 3-Hydroxybutanal
3. 2-Hydroxycyclopentanecarbaldehyde
4. 4-Oxopentanal
5. Di-sec.butyl ketone
6. 4-Fluoroacetophenone

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 2.

Write the structures of the products of the following reactions :

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 3.

Arrange the following compounds in increasing order of their boiling points.
CH₃CHO, CH₃CH₂OH, CH₃OCH₃, CH₃CH₂CH₃

Solution.

CH₃CH₂CH₃ < CH₃OCH₃ < CH₃CHO < CH₃CH₂OH

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 4.

Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.

1. Ethanal, Propanal, Propanone, Butanone.
2. Benzaldehyde, p-Tolualdehyde,

p – Nitrobenzaldehyde, Acetophenone. Hint: Consider steric effect and electronic effect.

Solution.

1. Butanone < Propanone < Propanal < Ethanal
2. Acetophenone < p-Tolualdehyde, Benzaldehyde < p-Nitrobenzaldehyde

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 5.

Predict the products of the following reactions :

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 6.

Give the IUPAC names of the following compounds :

Solution.

1. 3-Phenylpropanoic acid
2. 3-Methylbut-2-enoic acid
3. 2-Methylcyclopentanecarboxylic acid
4. 2,4,6-Trinitrobenzoic acid

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 7.

Show how each of the following compounds can be converted to benzoic acid.

1. Ethylbenzene
2. Acetophenone
3. Bromobenzene
4. Phenylethene (Styrene)

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 8.

Which acid of each pair shown here would you expect to be stronger ?
(i) CH₃CO₂H or CH₂FCO₂H
(ii) CH₂FCO₂H or CH₂ClCO₂H
(iii) CH₂FCH₂CH₂CO₂H or CH₃CHFCH₂CO₂H

Solution.

(i) H₂CFCOOH will be stronger of the two. The presence of electronegative F atom at the α-C causes electron withdrawal from the COOH and facilitates the release of H+.
(ii) CH₂FCO₂H is a stronger acid for the same reason as stated above. F is more electronegative than Cl, so it withdraws electrons from the carboxyl group to a greater extent.
(iii) CH₃CHFCH₂COOH is stronger. Although both the givenacidshaveFatomin them, it is the proximity of F in CH₃CHFCH₂COOH to the COOH group which makes it more acidic.

NCERT Exercises

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 1.

What is meant by the following terms? Give an example of the reaction in each case.

1. Cyanohydrin
2. Acetal
3. Semicarbazone
4. Aldol
5. Hemiacetal
6. Oxime
7. Ketal
8. Imine
9. 2,4-DNP derivative
10. Schiff’s base

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 2.

Name the following compounds according to IUPAC system of nomenclature :

1. CH₃CH(CH₃)CH₂CH2CHO
2. CH₃CH₂COCH(C₂H₅)CH₂CH₂Cl
3. CH₃CH=CHCHO
4. CH₃COCH₂COCH₃
5. CH₃CH(CH₃)CH₂C(CH₃)₂COCH₃
6. (CH₃)₃CCH₂COOH
7. OHCC₆H₄CHO-p

Solution.

1. 4-Methylpentanal
2. 6-Chloro-4-ethylhexan-3-one
3. But-2-en-1-al
4. Pentane-2, 4-dione
5. 3, 3, 5-Trimethylhexan-2-one
6. 3, 3-Dimethylbutanoic acid
7. Benzene-1, 4-dicarbaldehyde

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 3.

Draw the structures of the following compounds.

1. 3-Methylbutanal
2. p-Nitropropiophenone
3. p-Methylbenzaldehyde
4. 4-Methylpent-3-en-2-one
5. 4-Chloropentan-2-one
6. 3-Bromo-4-phenylpentanoic acid
7. p, p’-Dihydroxybenzophenone
8. Hex-2-en-4-ynoic acid

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 4.

Write the IUPAC names of the following ketones and aldehydes. Wherever possible, give also common names.

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 5.

Draw structures of the following derivatives.

1. The 2,4-dinitrophenylhydrazone of benz- aldehyde
2. Cyclopropanone oxime
3. Acetaldehydedimethylacetal
4. The semicarbazone of cyclobutanone
5. The ethylene ketal of hexan-3-one
6. The methyl hemiacetal of formaldehyde

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 6.

Predict the products formed when cyclohexanecarbaldehyde reacts with following reagents.

1. PhMgBr and then H₃O⁺
2. Tollens’reagent
3. Semicarbazide and weak acid
4. Excess ethanol and acid
5. Zinc amalgam and dilute hydrochloric acid

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 7.

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.

1. Methanal
2. 2-Methylpentanal
3. Benzaldehyde
4. Benzophenone
5. Cyclohexanone
6. 1-Phenylpropanone
7. Phenylacetaldehyde
8. Butan-1-ol
9. 2,2-Dimethylbutanal

Solution.

Aldol condensation is shown by those aldehydes or ketones which have at least one α-H atom while Cannizzaro reaction is undergone by aldehydes that have no α-H atom.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 8.

How will you convert ethanal into the following compounds?

1. Butane-1,3-diol
2. But-2-enal
3. But-2-enoic acid

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 9.

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 an electrophile

Solution.

The possible products of aldol condensation from propanal and butanal are

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 10.

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.

Solution.

(i) It is given that the compound reduces Tollens’ reagent. This proves that the compound is an aldehyde. Further, the fact that it undergoes Cannizzaro reaction shows that it lacks an α-H atom.

(ii) On oxidation it yields 1,2-benzenedicarboxylic acid. This shows that it is an o-substituted benzaldehyde. The only possible structure for the compound is :

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 11.

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 (8). (C) on dehydration gives but-1-ene. Write equations for the reactions involved.

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 12.

Arrange thefollowing compounds in increasing order of their property as indicated :

1. Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl fert-butyl ketone (reactivity towards HCN)
2. CH₃CH₂CH(Br)COOH,CH₃CH(Br)CH₂COOH, (CH₃)₂CHCOOH, CH₃CH₂CH₂COOH (acid strength)
3. Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 13.

Give simple chemical tests to distinguish between the following pairs of compounds.

1. Propanal and Propanone
2. Acetophenone and Benzophenone
3. Phenol and Benzoic acid
4. Benzoic acid and Ethyl benzoate
5. Pentan-2-one and Pentan-3-one
6. Benzaldehyde and Acetophenone
7. Ethanal and Propanal

Solution.

The given set of compounds may be distinguish by the following reaction.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 14.

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

1. Methyl benzoate
2. m-Nitrobenzoic acid
3. p-Nitrobenzoic acid
4. Phenylacetic acid
5. p-Nitrobenzaldehyde

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 15.

How will you bring about the following conversions in not more than two steps?

1. Propanone to Propene
2. Benzoic acid to Benzaldehyde
3. Ethanol to 3-Hydroxybutanal
4. Benzene to m-Nitroacetophenone
5. Benzaldehyde to Benzophenone
6. Bromobenzene to 1 -Phenylethanol
7. Benzaldehyde to 3-Phenyipropan-1 -ol
8. Benzaldehyde to a-Hydroxyphenylacetic acid
9. Benzoic acid to m-Nitrobenzyl alcohol

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 16.

Describe the following :

1. Acetylation
2. Cannizzaro reaction
3. Cross-aldol condensation
4. Decarboxylation

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 17.

Complete each synthesis by giving missing starting material, reagents or products

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 18.

Give plausible explanation for each of the following :

1. Cyclohexanone forms cyanohydrin in good yield but 2, 2,6 trimethylcyclohexa- none does not.
2. There are two – NH₂ groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
3. 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.

Solution.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 19.

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.

Solution.

(a) The given compound does not reduce Tollens’ reagent which implies that it is not an aldehyde.

NCERT Solutions for Class 12 Chemistry Chapter 12, Question 20.

Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?

Solution.

(i) Phenoxide ion has the following resonating structures :



(iii) The negative charge that rests on the electronegative O atom in carboxylate ion. We know that the presence of negative charge on an electronegative atom makes the ion more stable. For the same reason RCOO^– is more stable than the phenoxide ion where the oxygen has no negative charge on it. For the above two reasons carboxylate ion is more stable and has higher acidity than phenol.

NCERT Class 12 Chemistry

Class 12 Chemistry Chapters | Chemistry Class 12 Chapter 12

Chapterwise NCERT Solutions for Class 12 Chemistry

NCERT Solutions For Class 12 Chemistry Chapter 1 The Solid State
NCERT Solutions For Class 12 Chemistry Chapter 2 Solutions
NCERT Solutions For Class 12 Chemistry Chapter 3 Electro chemistry
NCERT Solutions For Class 12 Chemistry Chapter 4 Chemical Kinetics
NCERT Solutions For Class 12 Chemistry Chapter 5 Surface Chemistry
NCERT Solutions For Class 12 Chemistry Chapter 6 General Principles and Processes of Isolation of Elements
NCERT Solutions For Class 12 Chemistry Chapter 7 The p Block Elements
NCERT Solutions For Class 12 Chemistry Chapter 8 The d and f Block Elements
NCERT Solutions For Class 12 Chemistry Chapter 9 Coordination Compounds
NCERT Solutions For Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes
NCERT Solutions For Class 12 Chemistry Chapter 11 Alcohols Phenols and Ethers
NCERT Solutions For Class 12 Chemistry Chapter 12 Aldehydes Ketones and Carboxylic Acids
NCERT Solutions For Class 12 Chemistry Chapter 13 Amines
NCERT Solutions For Class 12 Chemistry Chapter 14 Biomolecules
NCERT Solutions For Class 12 Chemistry Chapter 15 Polymers
NCERT Solutions For Class 12 Chemistry Chapter 16 Chemistry in Everyday Life

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