In the following cases rearrange the compounds as directed:
(i) In an increasing order of basic strength:
`C_(6)H_(5)NH_(2), C_(6)H_(5)N(CH_(3))_(2), (C_(2)H_(5))_(2)NH` and `CH_(3)NH_(2)`
(ii) In a decreasing order of basic strength:
Aniline, p-nitroaniline and p-toluidine
(iii) In an increasing order of `pK_(b)` values:
`C_(2)H_(5)NH_(2), C_(6)H_(5)NHCH_(3), (C_(2)H_(5))_(2)NH and C_(6)H_(5)NH_(2)`

Explanation

Hint : (i) `C_(6)H_(5)NH_(2) lt C_(6)H_(5)N(CH_(3))_(2) lt CH_(3)NH_(2) lt (C_(2)H_(5))_(2)` (ii) p-toluidine `lt` toluidine `lt` aniline `lt` p-nitroaniline (iii) `(C_(2)H_(5))_(2)NH lt C_(2)H_(5)NH_(2) lt C_(2)H_(5)NH_(2) lt C_(6)H_(5)NHCH_(3) lt C_(6)H_(5)NH_(2)`.