Out of benzene, m-dinitrobenzene and toluene which will undergo nitration more easily and why?



Nitration of benzene is an electrophilic substitution reaction.

$N{{O}^{2+}}$ (nitronium) ion is the attacking electrophile. In toluene, one H of the ring is substituted by —C${{H}{3}}$group which is an electron releasing group and makes the electrons more readily available to the electrophile, whereas in m-dinitrobenzene, the two —$N{{O}^{2}}$ groups which are electron-withdrawing in nature makes the availability of electrons of the ring difficult to the electrophile.
Therefore, the ease of nitration decreases in the order toluene>p-${{H}