Free NCERT Solutions For Class 12 Chemistry Chapter 13 : Amines Free PDF Download

INTEX QUESTIONS

Question 1:
Classify the following amines as primary, secondary and tertiary:

Question 2:
(i) Write the structures of different isomeric amines corresponding to the molecular formula, .
C4H11N
(ii) Write IUPAC names of all the isomers.
(iii) What type of isomerism is exhibited by different pairs of amines?

Question 5:
Complete the following acid-base reactions and name the products:

Question 7:
Write chemical reaction of aniline with benzoyl chloride and write the name of the product obtained.

Solution 7:

Question 8:
Write structures of different isomers corresponding to the molecular formula, C3H9N. Write IUPAC names of the isomers which will liberate N2 gas on treatment with nitrous acid.

NCERT EXERCISES

Question 1:
Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.

Question 2:
Give one chemical test to distinguish between the following pairs of compounds:
(i) Methylamine and dimethylamine
(ii) Secondary and tertiary amines
(iii) Ethylamine and aniline
(iv) Aniline and benzylamine
(v) Aniline and N-Methylaniline.

Question 3:
Account for the following
(i) pKb of aniline is more than that of methylamine
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv) Although amino group is o and p — directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
(vi) Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
(vii) Gabriel phthalimide synthesis is preferred for synthesizing primary amines

Question 3: Arrange the following:
(i) In decreasing order of pKb values:.
C6H5NH2, C6H5NHCH3, (C2H5)2NH and C6H5NH2
(ii) In increasing order of basic strength:
C6H5NH2, C6H5N(CH3)2, (C2H5)2NH and CH3NH2
(iii) In increasing order of basic strength:
(a)Aniline, p-nitroaniline and p-toluidine
(b) C6H5NH2, C6H5NHCH3, C6H5CH2NH2
(iv) In decreasing order of basic strength in gas phase:
C6H5NH2, (C2H5)2NH, (C2H5)3N and NH3
(v) In increasing order of boiling point:
C5H5OH, (CH3)2 NH, C2H5NH2
(vi) In increasing order of solubility in water:
C6H5NH2, (C5H5)2NH, C2H5NH2

Question 5:
How will you convert:
(i) Ethanoic acid into methanamine
(ii) Hexanenitrile into 1-aminopentane
(iii) Methanol to ethanoic acid.
(iv) Ethanamine into methanamine
(v) Ethanoic acid into propanoic acid
(vi) Methanamine into ethanamine
(vii) Nitromethane into dimethylamine
(viii) Propanoic acid into ethanoic acid

Question 6:
Describe a method for the identification of primary, secondary and tertiary amines. Also write chemical equations of the reactions involved.

Question 7:
Write short notes on the following:
(i) Carbylamine reaction
(ii) Diazotisation
(iii) ‘Hofmann’s bromamide reaction
(iv) Coupling reaction
(v) Ammonolysis
(vi) Acetylation
(vii) Gabriel phthalimide synthesis

Question 8:
Accomplish the following conversions:
(i) Nitrobenzene to benzoic acid
(ii) Benzene to m-bromophenol
(iii) Benzoic acid to aniline
(iv) Aniline to 2,4,6-tribromofluorobenzene
(v) Benzyl chloride to 2-phenylethanamine
(vi) Chlorobenzene to p-chloroaniline
(vii) Aniline to p-bromoaniline
(viii)Benzamide to toluene
(ix) Aniline to benzyl alcohol.

Question 10:
An aromatic compound ‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br2 and KOH forms a compound ‘C. of molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B and C.

Question 11:

Question 12:
Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?

Question 13:
Write the reactions of (i) aromatic and (ii) aliphatic primary amines with nitrous acid.

Question 14:
Give plausible explanation for each of the following:
(i) Why are amines less acidic than alcohols of comparable molecular masses?
(ii) Why do primary amines have higher boiling point than tertiary amines?
(iii)Why are aliphatic amines stronger bases than aromatic amines?