Nitration of aniline with `HNO_3 + H_2SO_4` gives ?

Nitration of aniline by HNO_(3) + H_(2)SO_(4) mixture gives 51% para nitro derivate while 47% is meta nitro derivative and rest 2% ortho nitro derivative at 15^(@)C . In order to obtain 276 gm of p-nitro aniline what minimum mass of aniline should be taken?

Addition of conc. HNO_3 to conc. H_2 SO_4 gives

Nitration of aniline in presence of HNO_(3),H_(2)SO_(4),288K [give different products,among them the major percentage product is (A)P- nitro aniline (B) M-nitroaniline (C)O-nitro aniline (D)M & O-form equal amount

The nitration of propane with concentrated HNO_(3) gives :

In the nitration of benzene with conc. HNO_(3) and conc H_(2)SO_(4) the electrophile acting group is