Class 12th Chemistry 2017 Set3 Outside Delhi Board Paper Solution

Question 17

Give reasons for the following:

(a) Acetylation of aniline reduces its activation effect.

(b) CH3NH2 is more basic than C6H5NH2.

(c) Although -NH2 is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.

 

Answer

(a) Because with acetylation of aniline is result in decrease of electron density on nitrogen so activation effect reduces.

 

(b) CH3NH2 is more basic than C6H5NH2 because of positive I effect.

 

(c) Although amino group is o, p- directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline: Nitration is carried out in an acidic medium. In an acidic medium, aniline is protonated to give anilinium ion (which is meta-directing). For this reason, aniline on nitration gives a substantial amount of m-nitroaniline.

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