(i) \(\underset { Aniline }{ C_{ 6 }H_{ 5 }NH_{ 2 } } +CHCl_{ 3 }+\underset { (alc) }{ 3KOH } \quad { \longrightarrow }\underset { Phenyl\quad carbylamine }{ C_{ 6 }H_{ { 5 } }N_{ \rightarrow }^{ = }C } +3KCl+3H_{ 2 }O\)
(ii) \(\underset { Benzene\\ diazonium\\ Chloride }{ C_{ 6 }H_{ 5 }N_{ 2 }Cl } +\underset { Hypo\\ phosphorus\quad \\ acid }{ H_{ 3 }PO_{ 2 } } +H_{ 2 }O\quad { \longrightarrow }\underset { Benzene }{ C_{ 6 }H_{ 6 } } +\underset { Phosphoric\\ acid }{ H_{ 3 }PO_{ 3 } } +N_{ 2 }+HCl\)

It is because there is double bond character between C\(\rightarrow\)X bond due to which it cannot be broken easily that is why aromatic amines cannot be prepared by Gabriel phthalimide synthesis.

Ethyl alcohol has higher boiling point than ethlamine because there is stronger intermolecular H- bonding in ethanol than ethylamine due to more electronegativity of oxygen than nitrogen.

(i) 2-Propanamine \(\left( { 1 }^{ \circ } \right) \)
(ii) 1-Propanamine \(\left( { 1 }^{ \circ } \right) \)
(iii) N-Methyl-2-propanamine \(\left( { 2 }^{ \circ } \right) \)
(iv) 2-Methyl-2-propanamine \(\left( { 1 }^{ \circ } \right) \)

HNO acts as a base in the nitrating mixture (conc.HNO₃+conc.H₂SO₄). H₂SO₄ acts on HNO₃ to generate the electrophile, \({ NO }_{ 2 }^{ + }\) (nitronium ion)

Benzenesulphonyl chloride (C₆H₅SO₂CI) is called Hinsberg's reagent.

Benzenediazonium chloride is unstable. Therefore, it cannot be stored. Instead it is used immediately after its preparation.

Reagents required are: 
(i) sulphanilic acid
(ii) N, N-dimethylaniline
(iii)  NaNO₂ HCI and
(iv) a base.

Both aliphatic and aromatic nitro compounds on reduction in neutral medium, i.e., Zn dust and NH4Cl solution, give the corresponding hydroxylamines.
 \({ C }_{ 6 }{ H }_{ 5 }{ NO }_{ 2 }\quad \quad \overset { Zn/{ NH }_{ 4 }Cl,{ H }_{ 2 }O }{ \underset { \Delta }{ \longrightarrow } } \quad \quad { C }_{ 6 }{ H }_{ 5 }NHOH\\ Nitrobenzene\quad \quad \quad \quad \quad phenylhydroxylamine\\ \)
These hydroxylamines, when warmed with Tollens' reagent, are easily oxidized to the corresponding nitroso compounds and thus reduce Tollens' reagent to metallic silver
 \({ C }_{ 6 }{ H }_{ 5 }NHOH+2{ \left[ Ag{ \left( { NH }_{ 3 } \right) }_{ 2 } \right] }^{ + }+2{ OH }^{ - }\longrightarrow { C }_{ 6 }{ H }_{ 5 }N=O+2Ag\downarrow +4{ NH }_{ 3 }+2{ H }_{ 2 }O\)
This reaction is called Baker Mulliken's test and is used as a test for detection of nitro group in organic compounds.

(i) Aniline forms diazonium salt with NaNO₂/HCl which gives orange red dye with \(\beta\) -napththol. Ethyl amine does not give this test

(b) Ethyl amine gives foul smelling ethyl isocyanide on heating with chloroform and potassium hydroxide solution. Dimethyl amine does not give this test.
C₂H₅NH₂+CHCI₃+3KOH⟶C₂H₅NC+3KCI+3H₂O

(a) Test for dimethyl amine and ethanamine Ethanamine, being primary amine, on heating with chloroform and ethanolic potassium hydroxide form isocyanide which have foul smell whereas dimethyl does not give this kind of foul smell.

(b) Benzene diazonium chloride when treated with KI form iodobenzene. The reaction involved is as follows

(i) Methylamine and dimethylamine can be distinguished by the carbylamine test. Carbylamine test: Aliphatic and aromatic primary amines on heating with chloroform and ethanolic potassium hydroxide form foul-smelling isocyanides or carbylamines. Methylamine (being aliphatic primary amine) gives a positive carbylamine test, but dimethylamine does not.
(ii) Secondary and tertiary amines can be distinguished by allowing them to react with Hinsbergs reagent (benzenesulphonyl chloride, C₆H₅SO₂Cl). Secondary amines react with Hinsberg’s reagent to form a product that is insoluble in an alkali. For example, N, N−diethylamine reacts with Hinsberg’s reagent to form N, N−diethylbenzenesulphonamide, which is insoluble in an alkali. Tertiary amines, however, do not react with Hinsberg’s reagent amines, however, do not react with Hinsberg’s reagent.
(iii) Aniline and benzylamine can be distinguished by their reactions with the help of nitrous acid, which is prepared in situ from a mineral acid and sodium nitrite. Benzylamine reacts with nitrous acid to form unstable diazonium salt, which in turn gives alcohol with the evolution of nitrogen gas. 

(i) and (ii)
Eight isomers of C₄H₁₁N are
(a) \(\stackrel{4}{\mathrm{C}} \mathrm{H}_3-\stackrel{3}{\mathrm{C}} \mathrm{H}_2-\stackrel{2}{\mathrm{C}} \mathrm{H}_2-\stackrel{1}{\mathrm{C}} \mathrm{H}_2-\mathrm{NH}_2\)
                     Butan -1 -amine
                               (Primary)
(b)           CH₃
                    |
\(\stackrel{3}{CH}_3-{ }^2 \mathrm{CH}-\stackrel{1}{C} \mathrm{H}_2-\mathrm{NH}_2\)
            2-methyl propan -1-amine
                     (Primary)

(iii) Isomerism exhibited by different amines are:
(a) Chain isomers, i.e. have different carbon chains, (a) and (b), (c) and (d) (as discussed in part (i) and (ii)]
(b) Position isomers, i.e. functional group occupy different positions, (a) and (c), (b) and (d). 
(c) Metamers, i.e. different alkyl groups are attached to the same functional group, (e) and (f), (e) and (g).
(d) Functional isomers, i.e. they have different functional groups. All the three categories (1°, 2° and 3°) of amines are the functional isomers of each other.

(i) Propan-2-amine \(\left( { 1 }^{ \circ } \right) \),
(ii) Propan-1-amine \(\left( { 1 }^{ \circ } \right) \),
(iii) N-Methylpropan-2-amine \(\left( { 2 }^{ \circ } \right) \),
(iv) 2-Methylpropan-2-amine \(\left( { 3 }^{ \circ } \right) \),
(v) N-Methylbenzenamine or N-Methylaniline \(\left( { 2 }^{ \circ } \right) \),
(vi) N-Ethyl N-methylethanamine \(\left( { 3 }^{ \circ } \right) \),
(vii) 3-Bromobenzenamine or 3-Bromoaniline \(\left( { 1 }^{ \circ } \right) \).

Due to strong electron-donating effect of the -NH₂  group, the electron density increases at the 0-, positions. Further, when aniline is treated with Br₂ the Br⁺ attacks the benzene ring at o- and p-positions to form carbocation intermediates which are stabilized not only by the usual resonance of the Henzene ring. but also by the -NH₂ group as shown below: In case of o-bromination, the carbocation intermediate is stabilized not only by usual resonating structure (I, III and IV) but is also stabilized by resonance structure (II) in which the lone pair of electrons on the N. atom interacts with the positively charged carbon of the ring. Similarly, in case of p-bromination, the carbocation is stabilized not only by the usual resonating structures (V, VI, and VIII) but is also stabilized by the resonance structure (VII) in which the lone pair of electrons on the N-atom interacts with the positively charged carbon of the ring. These additional resonating structures (II and VII) increase the stability of the carbocation to such an extent that bromination occurs instantaneously at the p- and two. o- positions giving 2, 4, 6-tribromoaniline.

(i)  \({ C }_{ 6 }{ H }_{ 5 }-{ CONH }_{ 2 }\overset { { Br }_{ 2 }/KOH }{ \longrightarrow } { C }_{ 6 }{ H }_{ 5 }{ NH }_{ 2 }\)
\([A]\overset { { NaNO }_{ 2 }+HCI }{ \longrightarrow } { C }_{ 6 }{ H }_{ 5 }{ N }_{ 2 }^{ + }{ CI }^{ - }[B]\overset { KI }{ \longrightarrow } { C }_{ 6 }{ H }_{ 5 }I[C]\)
(ii) \({ CH }_{ 3 }CI\overset { KCN }{ \longrightarrow } { CH }_{ 3 }CN[A]\overset { { LiAIH }_{ 4 } }{ \longrightarrow } { CH }_{ 3 }{ CH }_{ 2 }{ NH }_{ 2 }[B]\overset { { CHCI }_{ 3 }+KOH }{ \longrightarrow } { CH }_{ 3 }{ CH }_{ 2 }NC[C]\)