Arrange the followingin decreasing order of ((m)/(o + p)) ratio. a. I. PhCH_(3), II. PhCBr_(3) III. PhCHBr_(2), IV. PhCH_(2)Br b. I. PhCH_(3), II. PhCBr_(3) III. PhCCl_(3), IV. PhCl_(3) c. I. ArN^(o+)R_(3) , II. ArCH_(2)N^(o+) R_(3) III. ArCH_(2)CH_(2)N^(o+) R_(3)

Arrange the followingin decreasing order of ((m)/(o + p)) ratio. a. I

1.	Arrange the followingin decreasing order of ((m)/(o + p)) ratio. a. I. PhCH_(3), II. PhCBr_(3) III. PhCHBr_(2), IV. PhCH_(2)Br b. I. PhCH_(3), II. PhCBr_(3) III. PhCCl_(3), IV. PhCl_(3) c. I. ArN^(o+)R_(3) , II. ArCH_(2)N^(o+) R_(3) III. ArCH_(2)CH_(2)N^(o+) R_(3)
Answer» Solution :GREATER the reactivity of the substiuent for `m-` direactor greater is the `((m)/(o + p))` ratio. `(I) gt (III) gt (IV)gt (I)` b. Reactivity of halogens is controlled by `-I` effect but orientation is controlledby `+R` effect. Reacticityorder is `I gt Br gt Cl gt F`. `(-CX_(3))` is `m-` director, but `(-CH_(3))` is `o-` and `p-` diredctor. `(IV) gt (II) gt (III) gt (I)`. e. (overset(o+)(-N)R_(3))` is `m-` director. `(I) gt (II) gt (III)`.