Question
in conversion of benzene to 4-chloro-1-nitrobenzene (reagent used is 1.cl2/fecl3 2.conc.hno3+conc h2so4) and in conversion of benzene to 1-bromo-3 -nitrobenzene(reagent used is 1.conc hno3+conc h2so4 2.br2/fe) , why ha\log een occupy different position in both case(para in 1st and meta in 2nd case) ??explain