13-1 Give the IUPAC names of the following :

Solution

13-2 How can nitriles be prepared from
(i) alkyl halides
(ii) acid amides
(iii) Grignard reagents ? Solution

13-3 How can isocyanides be prepared from
(i) alkyl halides
(ii) 1° amines ? Solution

13-4 What is an ambident nucleophile ? Explain with a suitable example. Solution

13-5 Complete the following equations :

Solution

13-6 Explain :
(i) Alkane nitriles have higher boiling points than the corresponding alkyl halides.
(ii) Boiling points of alkyl cyanides are higher than those of the corresponding isomeric isocyanides.
(iii) Isocyanides are hydrolysed only by acids and not by alkalis.
(iv) Isocyanides undergo addition reactions but cyanides do not.
(v) Methyl cyanide is soluble in water but methyl isocyanide not. Solution

13-7 How will you prepare:
(i) acetonitrile from acetic acid
(ii) methyl] isocyanide from methylamine;
(iii) thanenitrile from ethanamide ? Solution

13-8 What happens when :
(i) ethyl isocyanide reacts with sulphur;
(ii) acetaldoxime is heated with phosphorus pentoxide;
(iii) cyanides are subjected to partial reduction followed by hydrolysis;
(iv) methyl cyanide is treated with methyl magnesium bromide and the product is hydrolysed? Solution

13-9 How would you carry out the following conversions ?
(i) Propane nitrile to propanamine
(ii) Methyl cyanide to acetaldehyde
(iii) C₂H₅CN to C₂H₅CHO
(iv) Acetic acid to methyl cyanide
(v) Ethanamine to ethylcarbylamine Solution

13-10 State one use of acetonitrile. Solution

13-11 Alkyl nitriles have lower boiling points than the corresponding carboxylic acids. Explain. Solution

13-12 What are main points of difference between alkyl cyanides and isocyanides ? Solution

13-13 How will you distinguish ethyl cyanide from ethyl isocyanide ? Solution

13-14 Give the structural formula of the following :
(i) Acetonitrile
(ii) Propyl cyanide
(iii) Ethylcarbylamine
(iv) 2-propylcarbylamine
(v) Acrylonitrile Solution

13-15 Identify A, B and C in the following equations.

Solution

13-16 Write a short note on the synthetic applications of cyanides. Solution

13-17 Write the IUPAC names of the following compounds :

Solution

13-18 Write the structural formulae of the following :
(i) 2-nitrobutane
(ii) 2, 4-dinitropentane Solution

13-19 Draw the structures of isomeric nitroalkanes and alkyl nitrites having the molecular formula C₂H₅NO₂ Solution

13-20 Draw the structures of isomeric nitroalkanes and alkyl nitrites having the molecular formula C₃H₇NO₂ Solution

13-21 How are alkyl nitrites different from nitroalkanes? Explain with suitable examples. Solution

13-22 What is vapour phase nitration? Give one of its applications. Solution

13-23 How will you prepare the following?
(i) Nitroethane from bromoethane
(ii) Nitromethane from methane
(iii) Ethyl nitrite from iodoethane
(iv) Nitrobenzene from benzene Solution

13-24 What is an ambident group? Give an example. Solution Ans 13-4 same as

13-25 What is vapour phase nitration? Describe the preparation of nitroalkanes and alkyl nitrites from alkyl halides. Explain why the boiling points of nitroalkanes are higher than those of the corresponding alkanes? Solution

13-26
(a) Write the general formula for Nitroalkanes and alkyl nitrites.
(b) How are nitroalkanes prepared from alkanes?
(c) What happens when nitroethane is treated with lithium aluminium hydride? Solution

13-27 What happens when
(i) nitroethane is reduced with zinc dust and NH₄Cl;
(ii) nitroethane is boiled with HCl;
(iii) nitromethane is treated with Cl₂ in the presence of NaOH;
(iv) nitrobenzene is reduced in alkaline medium? Solution

13-28 Explain the following :
(i) The boiling points of nitroalkanes are higher than those of isomeric alkyl nitrites.
(ii) 3° nitroalkanes do not dissolve in NaOH.
(iii) The boiling points of nitroalkanes are much higher than those of the hydrocarbons of comparable molecular mass
(iv) 1° and 2° nitroalkanes exhibit acidic character in the presence of NaOH. Solution

13-29 Explain the behaviour of different types of nitroalkanes towards nitrous acid. Solution

13-30 Complete the following equations :

Solution

13-31 Account for the following :
(i) Direct nitration of alkanes is not a good method for the preparation of nitroalkanes in the laboratory.
(ii) An alcoholic solution of AgNO₂ when treated with alkyl halides gives mainly nitroalkanes, while that of NaNO₂ gives mainly alkyl nitrites.
(iii) In nitrobenzene, electrophilic substitution takes place at m-position.
(iv) Nitrobenzene does not undergo Friedel-Crafts reaction. Solution

13-32 How will you distinguish nitroethane from ethyl nitrite ? Solution

13-33 Give the IUPAC names of the following :

Solution (i) Propan-1-amine,
(ii) N-methylpropan-1-amine,
(iii) Propan-2-amine,
(iv) Phenylethanamine,
(v) N, N-dimethyl-3-methylpentan-3-amine,
(vi) Prop-1- en-1-amine,
(vii) N, N-dimethylbutan-2-amine,
(viii) 3-methylbenzenamine or 3-methylaniline,
(ix) 3-phenylpropan-1-amine,
(x) 2, 4, 6-tribromoaniline,
(xi) N-ethyl-N-methylbenzenamine,
(xii) N-ethyl-N-methylpropan-1-amine,
(xiii) Trimethylanilinium bromide,
(xiv) N, N-dimethylanilinium acetate

13-34 What are primary, secondary and tertiary amines? Give one example of each. Solution

13-35 What are primary, secondary and tertiary amines? Explain how can these amines be distinguished from one another? Solution

13-36 Write the IUPAC name of diethylamine. How will you obtain it from nitroethane? Solution

13-37 How is ethylamine prepared from acetonitrile? Compare its basic character with that of ammonia. Solution

13-38 How is aniline prepared commercially? Describe the carbylamine test for primary amines. Solution

13-39
(i) How is aniline synthesised by Hofmann reaction?
(ii)Why is aniline a weaker base than methylamine? Solution

13-40 Write balanced chemical equation for the preparation of methylamine from acetamide. Solution

13-41 Give the industrial preparation of aniline either from nitrobenzene or from chlorobenzene. Solution

13-42 Give the reasons for the following :
(i) It is difficult to prepare pure amines by ammonolysis of alkyl halides.
(ii) C₂H₅NH₂ is soluble in water but CgHsNHz is insoluble. Solution

13-43 How will you prepare
(i) methylamine from acetic acid;
(ii) aniline from benzene;
(iii) methylamine from ethylamine;
(iv) ethanamine from propanamide;
(v) aniline from benzamide;
(vi) isopropylamine from acetone;
(vii) ethylamine from acetaldehyde;
(viii) chlorobenzene from aniline ?
Solution

13-44 Explain giving reasons :
(i) Arylamines are weaker bases than alkylamines.
(ii) The boiling points of amines are lower than those of the corresponding alcohols.
(iii) Silver chloride dissolves in methylamine solution. Solution

13-45 Illustrate each of the following with an example :
(i) Substitution reactions in aromatic primary amines
(ii) Hinsberg’s test. Solution

13-46 Account for the following :
(i) Tertiary amines do not undergo acylation.
(ii) Ethylamine is more basic than ammonia.
(iii) Secondary amines are more basic than primary amines.
(iv) Boiling point of ethylalcohol is more than that of ethylamine.
(v) Amines are higher boiling point compounds hydrocarbons of corresponding molecular masses.
(vi) Before nitration, aniline is converted into acetanilide.
(vii) In water, methylamine reacts with ferric chloride to precipitate ferric hydroxide.
(viii} Aniline is acetylated to prepare derivative.
(ix) Ammonolysis of an alkyl halide generally does not yield a pure amine.
Solution

13-47 What happens when :
(i) methylamine is heated with chloroform in the presence of an alkali;
(ii) a mixture of alcohol and ammonia in vapour state is passed over heated aluminium oxide as catalyst? Solution

13-48 Describe carbylamine test and illustrate it with a balanced chemical equation. Solution

13-49 Predict the products and balance the following reactions :

Solution

13-50 How are the following conversions carried out?
(i) Methylamine to ethylamine
(ii) Ethylamine to methylamine
(iii) Aniline to fluorobenzene
(iv) Aniline to chlorobenzene
(v) Aniline to benzoic acid
(vi) Nitrobenzene to phenol
(vii) Aniline to benzonitrile
(viii) Aniline to p-nitroaniline Solution

13-51 Write the chemical equation for each of the following conversion reactions :
(i) Ethyl cyanide to ethylamine
(ii) Aniline to N-phenylethanamide Solution

13-52 Account for the following :
(i) Alkylamines are stronger bases than arylamines.
(ii) Toluene is more easily nitrated than benzene. Solution

13-53 With the help of balanced chemical equations, show what happens when
(i) ethylamine reacts with silver chloride;
(ii) ethylamine is treated with cupric ions;
(iii) benzamide reacts with Br₂ and alcoholic KOH;
(iv) aniline is heated with conc. H₂SO₄, at 475 K;
(v) acetaldoxime is heated with LiAlH₄
(vi) methylamine is treated with ethyl magnesium bromide? Solution

13-54 Arrange the following amines in the increasing order of basic strength and explain the order also: Methylamine, Dimethylamine, Trimethylamine. Solution

13-55 How will you convert
(i) C₂H₅NH₂ into C₂H₅NC;
(ii) aniline into sulphanilic acid
(iii) aniline into ortho-nitroaniline? Solution

13-56 Complete the following reactions :

Solution

13-57 How will you distinguish C₆H₅NH₂ from C₂H₅NHC₂H₅? Write the chemical equation for the reaction involved. Solution

13-58
Fill in the blanks with reagents/organic compounds in the following sequence of reactions :

Solution

13-59 Write the structures of the reagents/organic compounds A to F in the following sequence of reactions :

Solution

13-60 Write the structures of reagents/organic compounds A to F in the following sequence of reactions :

Solution

13-61 Write the structures of organic compounds A to F in the following sequence of reactions.

Solution

13-62 Write structures of A to F in the following sequence of chemical reactions :

Solution

13-63 Cyclohexylamine is a stronger base than aniline. Explain. Solution

13-64 Describe diazotisation and coupling reaction between benzendiazonium chloride and aniline. Solution

13-65 Arrange the following in the increasing order of their basic strength :
Ammonia, Methylamine, Dimethylamine, Aniline, N-methylaniline Solution

13-66 What is Hinsberg’s reagent? Give the reactions of Hinsberg’s reagent with primary and secondary amines. Solution

13-67 Mention two important uses of sulphanilic acid. Solution

13-68 Give an example of zwitter ion. Solution

13-69 State the reagents for the following conversion :
Benzene ——> Nitrobenzene ——> Aniline ——> Aniline hydrochloride ——> Benzene diazonium chloride Solution

13-70 Mention the chief use of quaternary ammonium salts derived from long chain amines. Solution

13-71 Complete the following reactions :

Solution

13-72 Explain why :
(i) Alkylamines are stronger bases than arylamines.
(ii) Aniline is acetylated to prepare its mononitro derivative. Solution

13-73
(a) Why is it difficult to prepare pure amines by ammonolysis of alkyl halides?
(b) Draw the structures and state the IUPAC names of four isomeric amines of formula C₇H₉N that contain a benzene ring. Solution

13-74 Before reacting aniline with HNO₃ for nitration, it is converted to acetanilide. Why is this done and how is nitroaniline obtained subsequently? Solution

13-75 Identify substances A and B in each of the following sequence of reactions :

Solution

13-76 Write chemical tests to distinguish between aniline and N-methylaniline. Solution

13-77 Give the structural formula and name of the product of the reaction : Chloroform is heated with aniline in the presence of alc. KOH. Solution

13-78 Of methylamine and aniline, which is a stronger base and why? Solution

13-79
(a) Give reasons for the following :
(i) Before nitration, aniline is converted into acetanilide.
(ii) Aromatic amines are less basic than aliphatic amines.
(iii) Silver chloride dissolves in methylamine solution.
(b) Give one chemical test to distinguish between CH₂CH₂NH₂ and CH₃NHCH₃.
Solution

13-80
(a) Suggest chemical reactions for the following conversions :
(i) Aniline to benzoic acid,
(ii) n-hexanenitrile to 1-aminopentane,
(iii) p-chloroaniline to p-chlorobenzylamine.
(b) Account for the following :
(i) Aqueous solution of methylamine reacts with iron (II)
chloride to precipitate iron (III) hydroxide.
(ii) The boiling points of amines are lower than those of corresponding alcohols. Solution

13-81 Account for the following observations :
(i) Silver chloride dissolves in aqueous methylamine solution.
(ii) Tertiary amines do not undergo acylation reaction.
(iii) Aniline readily reacts with bromine to give 2, 4, 6-tribromoaniline. Solution

13-82
(a) How is aniline obtained from benzene?
(b) Why are the secondary amines more basic than primary amines? Explain.
(c) Write the complete chemical reactions for the conversion of aniline to sulphanilic acid.
(d) Mention two important uses of sulphanilic acid.
(e) Write a chemical reaction of aniline which may distinguish it from ethylamine. Solution

13-83 Write one chemical equation each to exemplify the following reactions :
(i) Carbylamine reaction.
(ii) Hofmann bromamide reaction. Solution

13-84 How is aniline prepared on a large scale? How will you convert it into
(i) Benzonitrile,
(ii) Acetanilide? Write the reaction and conditions in each case. Solution

13-85 Explain why the aromatic amines are less basic than ammonia and aliphatic amines. Solution

13-86 Explain the following observations :
(i) In aqueous solution, the K_b order is
Et₂NH > Et₃N > EtNH₂.
(ii) Nucleophilic substitution of p-nitrochlorobenzene is easier than that of chlorobenzene.
(iii) Amines are more basic than comparable alcohols. Solution

13-87 Give appropriate reasons for each of the following observations :
(i) The aromatic amines are weaker bases than aliphatic amines.
(ii) Even under mild conditions, aniline on bromination gives 2, 4, 6-tribromoaniline instantaneously. Solution

13-88 Give chemical test to distinguish between C₆H₅CH₂NH₂ and C₆H₅NH₂. Solution

13-89
(a) Assign a reason for the following statement :
Alkylamines are stronger bases than arylamines. (b) How would you convert methylamine into ethylamine? Solution

13-90
How is the basic strength of aromatic amines affected by the presence of an electron releasing group on the benzene ring? Solution

13-91 (i) Give one chemical test to distinguish between CH₃.CH₂. NH₂ and CH₃.NH.CH₃.
(ii) Write the chemical reaction for the reduction of nitroethane by LiAlH₄. Solution

13-92 How would you achieve the following conversions :
(i) Nitrobenzene to aniline
(ii) An alkyl halide to quaternary ammonium salt
(iii) Aniline to benzonitrile?
Write the chemical equation with reaction conditions in each case Solution

13-93 Why do amines react as nucleophiles? Solution