Răspuns:
CnH2n+ Br2-----> CnH2nBr reactie de aditie
in 1mol derivat (14n+2x80)g....exista........2x80gBr in 100g.........................................85,10g
16000= 85,1(14n+160)---. > n=2 --->etena
CH2=CH2+ Br2----> CH2Br-CH2Br
apa de brom se decoloreaza
Explicație: