(a) `2 gt 1 gt 3 gt 4 gt [(2)` Aniline (standard) `gt (1) - NO_2` at m-position , (only `-I` effect ar `m) gt (3) - NO_2` at `p-(-I` and `-R) gt (4)- NO_2` at `o (-I` and `-R`, but `-I` at `o- gt m - gt p -)` net `overline e` - withdrawing power of `-NO_2` at `orarr p- gt m -]` (b) `2 gt 1 [(2) sp` character due to `C -= C gt (1) sp^2` character due to `(C = C)` bond]
`( c) 1 gt 2 gt 3 [(1) 3^@` amine `gt (2)` Aromatic heterocycle amine, `L P overline e^, s` are not delocalised) `gt (3) sp` character due to `(C -= N)` group.]
(d) `1 gt 2 gt 3 gt [(1) - NO_2` at `p-(-I` and `-R) gt (2) - CN` at `p- (- I` and `-R)` but `- I`of `-NO_2 gt (-CN) gt (3)` Standard (phenol)]
( e) `1 gt 2 gt 3 gt 4 [(1) 1^@` aliphati camine `gt (2)` Aromatic amine (Aniline) `gt (3), - NO_2` at `p- (-I` and `-R) gt (4)` Three `- NO_2` groups `(-I` and `-R)`
(f) `a gt b gt c` (i) Structure `(a)` has no resonance structure, so `L P overline e^, s` on `N` are available for donation, resulting in `(a)` as the strongest base.
(ii) In (b) and (c), `LP overline e^, s` on `N` are in resonance but at `C EWG (C = O)` is present.
(g)
(h)
In case of `F`, both `-I` and `-R` effects are considered because of the effective overlap of `2 p (F) - 2p ( C)`. But in other halogens. only `-I` effect is considered due to the ineffective overlap. So net `overline e` - withdrawing power of `C1 gt F gt Br gt I`. Hence, the acidic order is. `I gt II gt III gt IV gt V` (refer to `pK_a` , Table).
(i) ( I) `c gt b gt a`
(i) (c) is p-nitrophenol, which is stronger than o-nitro phenol `(b)` (due to intramolecular `H`-bonding)
(ii) In (a), acidic character is decreasing due to `+ I` and `H.C` effects of `(Me)` group at o-position.
(II) `c gt d gt b`
(i) Due to `EWG (NO_2` group) (`-I` and `-R` effects), `C` is most acidic.
(ii) Due to ortho-effect, `(a)` is more acidic than `(b)` and `(d)` but less than `(c)`
(iii) Due to only `+I` effect of `Me` at `m-`position, `(d)` is more acidic than `(b)`
(iv) Due to `+ I` and `H.C` effects of `Me` at `p-`position (b) is least acidic.
(III) `a gt c gt d ("Phenol" )gt "Aldehyde "gt (C = C) (sp` character) `gt(C = C) (sp^2` character).