benzenul are NE=4 => arena are un ciclu benzenic + o catena laterala nesaturata cu o dubla legatura
daca avea NE=4 ca benzenul, tot cu catena laterala, formula: CnH2n-6
avand NE=5 => formula: CnH2n-8
md=c*ms/100=4*80/100=3,2g Br2
14n-6.........160g
CnH2n-8 + Br2 -> CnH2n-8Br2
2,36............3,2g
14n-8=2,36*160/3,2=118g arena
14n=126 => n=9
C9H10