Aldehydes ketones and carboxylic acid part 2

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NCERT Class 12 Chemistry Chapter-wise Solutions

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

CHAPTER TWELVE ALDEHYDES, KETONES AND CARBOXYLIC ACIDS

• 12.1 Nomenclature and Structure of Carbonyl Group
• 12.2 Preparation of Aldehydes and Ketones
• 12.3 Physical Properties
• 12.4 Chemical Reacxtions
• 12.5 Uses of Aldehydes and Ketones
• 12.6 Nomenclature and Structure of Carboxyl Group
• 12.7 Methods of Preparation of Carboxylic Acids
• 12.8 Physical properties
• 12.9 Chemical Reactions
• 12.10 Uses of carboxylic Acids

NCERT Solutions class 12 Chemistry aldehydes ketones and carboxylic acid part 2

11. An organic compound (A) (molecular formula ) 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.

12. 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) , , (acid strength)

(iii) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)

13. 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

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

(i) Methyl benzoate

(ii) m-Nitrobenzoic acid

(iii) p-Nitrobenzoic acid

(iv) Phenylacetic acid

(v) p-Nitrobenzaldehyde.

15. 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

16. Describe the following:

(i) Acetylation

(ii) Cannizzaro reaction

(iii) Cross aldol condensation

(iv) Decarboxylation

17. Complete each synthesis by giving missing starting material, reagent or products

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

(viii)

(ix)

(x)

(xi)

18. 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 – 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.

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.

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

 covers both organic and inorganic chemistry. Please note that CBSE has reduced the syllabus for class 12 Chemistry. So, you must check the latest syllabus of CBSE while going through the NCERT solution of any chapter given in the class 12 NCERT book.