Amines

$R-N{H}_2\underset{273K}{\overset{HN{O}_2\left(aq.\right)}{\to }}R-\stackrel{\oplus }{N_2}\underset{298K}{\overset{H_{2}O/-N_2\uparrow }{\to }}R-OH$

1° aliphatic amine           Diazonium salt                Alcohol

Aniline show acid-base reaction with AlCl₃

aniline is a Lewis base while AlCl₃ acts as lewis acid.

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(8.00)

Therefore option (b) is correct.

Nitrogen, sulphur and halogens are tested in an organic compound by lassaigne's test.
The organic compound is fused with sodium metal as to convert these elements into ionisable inorganic substances.
Na + C + N → NaCN
2Na + S → Na? S
2Na + X? → 2NaX
The cyanide, sulphide or halide ions can be confirmed in aqueous solution by usual test.

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During nitration of aniline, meta product is also formed, it is because of due to presence of anilinium ion. In anilium $-\stackrel{+}{N}{H}_3$  group is meta directing group.

Sodium fusion extract is Lassaigne method to defect sulphur, nitrogen, phosphorous and halogens.

X is NH?
With mercurous nitrate it forms Hg + HgNH? Cl
Black