Chapter 13 – Amines Questions and Answers: NCERT Amines for Class 12 Chemistry

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Class 12 Chemistry chapter 13 - Amines - Questions and Answers of NCERT Book Solutions.

13.1. Classify the following Amines as primary, secondary and tertiary:

Ans: (i) 1° (ii) -3° (iii) 1° (iv) 2°

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13.2. Write the structures of different isomeric Amines corresponding to the molecular formula, C4H11N.
(i) Write the IUPAC names of all the isomers
(ii) What type of isomerism is exhibited by different types of Amines?

Ans: Eight isomeric Amines are possible

Isomerism exhibited by different Amines
Chain isomers: (i) and (ii) ; (iii) and (iv) ; (i) and (iv)
Position isomers: (ii) and (iii) ; (ii) and (iv)
Metamers: (v) and (vi) ; (vii) and (viii)
Functional isomers: All the three types of Amines are the functional isomers of each other.

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13.3. How will you convert:
(i) Benzene into aniline
(ii) Benzene into N,N-dimethylaniline
(iii) Cl-(CH2)4-Cl into Hexane -1,6- diamine

Ans:

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13.4. Arrange the following in increasing order of their basic strength :
(i) C2H5NH2, C6H5NH2, NH3, C6H5CH2NH2, (C2H5)2NH
(ii) C2H5NH2, (C2H5)2NH, (C2H5)3N, C6H5NH2
(iii) CH3NH2, (CH3)2NH, (CH3)3N, C6HsNH2, C6H5CH2NH2

Ans:In general, the basic character of ammonia (NH3) and the Amines is linked with the availability of the lone electrons pair on the nitrogen atom. In other words, these are all Lewis bases. Amines act as Lewis bases due to the presence of lone electron paîr on the nitrogen atom. Since the nitrogen atom is sp³ hybridised, its electron attracting tendency is considerably reduced. It can readily lose its electron pair and acts as a base. For example, Amines form hydroxides with water.

Here Kt is called dissociation constant for the base. Greater the Kb value stronger will be the base. The basic strengthof Amines can also be expressed as pKb value which is related to Kb as :

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13.5. Complete the following acid-base reactions and name the products:
(i) CH3CH2CH2NH2+HCl ——–>
(ii) (C2H5)3 N+HCl ——–>

Ans:

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13.6. Write reactions of the final alkylation product of aniline with excess of methyl iodide in the presence of sodium carbonate solution.

Ans:

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13.7. Write chemical reaction of aniline with benzoyl chloride and write the name of the product obtained.

Ans:

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13.8. Write structures of different isomers corresponding to the molecular formula, C3H9N. Write IUPAC names of the isomers which will liberated N2 gas on treatment with nitrons acid.

Ans: In ‘all, four structural isomers are possible. These are:

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13.9. Convert:
(i) 3-Methylanilineinto3-nitrotoluene
(ii) Aniline into 1,3,5- Tribromo benzene

Ans:

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NCERT Book for Class 12 Chemistry
The Solid State
Solutions
Electrochemistry
Chemical Kinetics
Surface Chemistry
General Principles and Processes of Isolation of Elements
The p -Block Elements
The d- and f - Block Elements
Coordination Compounds
Haloalkanes and Haloarenes
Alcohols, Phenols and Ethers
Aldehydes, Ketones and Carboxylic Acids
Amines
Biomolecules
Polymers
Chemistry in Everyday Life

Last Updated on: Feb 26, 2024