Chemistry

Amines

Question:

The reagents that can be used to convert benzene diazonium chloride to benzene are
(a) SnCl2/HCl (b) CH3CH2OH
(c) H3PO2 (d) LiAlH4

Answer:

(a, b)
ncert-exemplar-problems-class-12-chemistry-amines-31

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Amines

Q 1.

Which of the following reactions belong to electrophilic aromatic substitution?
(a) Bromination of acetanilide
(b) Coupling reaction of aryldiazonium salts
(c) Diazotisation of aniline
(d) Acylation of aniline

Q 2.

Which of the following is the weakest Bronsted base?
ncert-exemplar-problems-class-12-chemistry-amines-3

Q 3.

Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?
(a) Acetyl chloride/pyridine followed by reaction with cone. H2SO4 + cone.
(b) Acetic anhydride/pyridine followed by cone. H2SO4 + cone. HNO3
(c) Dil. HCl followed by reaction with cone. H2SO4 + cone. HNO3
(d) Reaction with cone. HNO3 + cone. H2S04

Q 4.

The best reagent for converting-2-phenylpro-panamide into 1-phenylethana- mine is .
(a) excess H2/Pt (b) NaOH /Br2
(c) NaBH4/methanol (d) LiAlH4/ether

Q 5.

Which of the following should be most volatile?
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Q 6.

The best reagent for converting 2-phenylpro-panamide into-2-phenyl- propanamine is .
(a) excess H2
(b) Br2 in aqueous NaOH
(c) iodine in the presence of red phosphorus
(d) LiAlH4 in ether

Q 7.

Assertion (A): N, N-diethylbenzene sulphonamide is insoluble in alkalf. Reason (R): Sulphonyl group attached to nitrogen atom is strong electron withdrawing group.

Q 8.

Which of the following amines can be prepared by Gabriel synthesis?
(a) Isobutyl amine (b) 2-Phenylethylamine
(c) N-Methylbenzylamine (d) Aniline

Q 9.

Which is the role of HNO3 in the nitrating mixture used for nitration of benzene?

Q 10.

Which of the following reactions are correct?
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Q 11.

Complete the following reactions:
ncert-solutions-for-class-12-chemistry-amines-37

Q 12.

What is the role of pyridine in the acylation reaction of amines?

Q 13.

Why is benzene diazonium chloride not stored and is used immediately after its preparation?

Q 14.

Complete the following reaction.
ncert-exemplar-problems-class-12-chemistry-amines-52

Q 15.

Which of the following cannot be prepared by Sandmeyer's reaction?
(a) Chlorobenzene (b) Bromobenzene
(c) Iodobenzene (d) Fluorobenzene

Q 16.

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

Q 17.

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

Q 18.

ncert-exemplar-problems-class-12-chemistry-amines-21

Q 19.

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?

Q 20.

Assertion (A): Hofmann's bromamide reaction is given by primary amines. Reason (R): Primary amines are more basic than secondary amines.

Q 21.

Under what reaction conditions (acidic/basic), the coupling reaction of aryl diazonium chloride with aniline is carried out?

Q 22.

Identify A and B in the following reaction.
ncert-exemplar-problems-class-12-chemistry-amines-57

Q 23.

Arrange the following compounds in increasing order of dipole moment: CH3CH2CH3, CH3CH2NH2, CH3CH2OH.

Q 24.

Arrange the following:
(i) In decreasing order of pKb values: .
C2H5NH2,C6H5NHCH3,(C2H5)2NH and C6H5NH2
(ii) In increasing order of basic strength:
C6H5NH2, C6H5N(CH3)2, (C2H5)2 NH and CH3NH2.
(iii) In increasing order of basic strength:
(а)Aniline,p-nitroaniline andp-toluidine
(b)C6H5NH2, C6H5NHCH3, C6H5CH2NH2
(iv) In decreasing order of basic strength in gas phase:
C2H5NH2, (C2H5)2NH, (C2H5)3N and NH3
(v) In increasing order of boiling point:
C2H5OH, (CH3)2NH, C2H5NH2
(vi) In increasing order of solubility in water:
C6H5NH2,(C2H5)2NH,C2H5NH2

Q 25.

The correct IUPAC name for CH2 = CHCH2NHCH3 is
(a) allylmethylamine (b) 2-amino-4-pentene
(c) 4-aminopent-l-ene . (d) N-methylprop-2-en-l-amine.

Q 26.

Among the following amines’ the strongest Bronsted base is
ncert-exemplar-problems-class-12-chemistry-amines-25

Q 27.

Why does acetylation of -NH2 group of aniline reduce its activating effect?

Q 28.

Write down the IUPAC name of
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Q 29.

Which of the following species are involved in the carbylamine test?
(a) R-NC (b) CHCl3 (c) COCl2 (d) NaN02 + HCl

Q 30.

What is the structure and IUPAC name of the compound, allyl amine?

Q 31.

Why is NH2 group of aniline acetylated before carrying out nitration?

Q 32.

Which of the following compounds is the weakest Bronsted base?
ncert-exemplar-problems-class-12-chemistry-amines-24

Q 33.

What is Hinsberg reagent?

Q 34.

Match the reactions given in Column 1 with the statements given in Column II.
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Q 35.

Give the structures of A,B and C in the following reaction:
ncert-solutions-for-class-12-chemistry-amines-34
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Q 36.

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.

Q 37.

Give the structure of 'A' in the following reaction.
ncert-exemplar-problems-class-12-chemistry-amines-44

Q 38.

Write following conversions:
(i) nitrobenzene –> acetanilide
(ii) acetanilide –> p-nitroaniline

Q 39.

A solution contains 1 g mol each of p-toluene diazonium chloride and p-nitrophenyl diazonium chloride. To this 1 g mol of alkaline solution of phenol is added. Predict the major product. Explain your answer.

Q 40.

Assertion (A): Aromatic 1 ° amines can be prepared by Gabriel phthalimide synthesis.
Reason (R): Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.

Q 41.

Assertion (A): Acetanilide is less basic than aniline.
Reason (R): Acetylation of aniline results in decrease of electron density on nitrogen.

Q 42.

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

Q 43.

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

Q 44.

Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary  amines.  
(i) (CH3)2 CHNH2 (ii) CH3(CH2)2NH2 (iii) CH3NHCH(CH3)2
(iv) (CH3)3 CNH2 (v) C6H5NHCH3(vi) (CH3CH2)2NCH3
(vii)m-BrC6H4NH2

Q 45.

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

Q 46.

Amongst the given set of reactants, the most appropriate for preparing 2 ° amine is .
(a) 2 ° R – Br + NH3
(b) 2 ° R – Br + NaCN followed by H2/Pt
(c) 10 R – NH2 + RCHO followed by H2/Pt
(d) 1 ° R – Br + (2 mol) + potassium phthalimide followed by H3O+/heat

Q 47.

Arenium ion involved in the bromination of aniline is.
ncert-exemplar-problems-class-12-chemistry-amines-34

Q 48.

What is the product when C6H5CH2NH2 reacts with HN02?

Q 49.

What is the best reagent to convert nitrile to primary amine?

Q 50.

Explain why is MeNH2 stronger base than MeOH?