What is the correct reactivity order of the following electrophites? Toluene, p-H_3C-C_6H_4 - CH_3,p-CH_3- C_6H_4-NO-2 ,p-O_2N-C_6H_4-NO_2

What is the correct reactivity order of the following electrophites?

1.	What is the correct reactivity order of the following electrophites? Toluene, p-H_3C-C_6H_4 - CH_3,p-CH_3- C_6H_4-NO-2 ,p-O_2N-C_6H_4-NO_2
Answer» SOLUTION : Methyl group is an electron releasing group. It increases RECTIVITY of benzene ring with an electrophile. On the other hand nitro is an electron with drawing group. It deactivates the benzene ring towards reacting with an electrophile. On the basis of this, we can CONCLUDE that greater the number of methyl groups attached to the ring greater is its reactivity with an electrophile, and greater the number of nitro groups on the thrring, smaller is its reactivity with an electrophile. The activating ability order of various groups is : `NH_2 > - NHR > - NR_2 > - OH > - OR > - X`.