What is function of Halogen carrier in direct halogenation of Benzene ring (or in electrophilic substitution of arenes) Explain with mechanism.

What is allylic halogenation?

Amino group in aniline is o, p-directing and activating in electrophilic substitution reactions.

Halogens are highly reactive. Explain.

Explain S_N^2 reactions. What is the preference order of different alkyl halides to undergo nucleophilic substitution reaction via SN2 mechanism ?

Explain how does -OH group attached to a carbon of benzene ring Activates it towards electrophilic substitution .

Explain the fact that in aryl ethers (i) the alkoxy group activates the benzene ring towards electrophilic substitution and (ii) it directs the incoming substituents to ortho -and para -positions in benzene ring .