See, benzene has that stable resonance structure — it doesn't have proper pi bonds to easily add bromine like hexene does. Hexene's double bond is localised and reactive. So benzene won't decolourise bromine water under normal conditions, but an alkene will.
I remember this because my son, for his engineering entrance, had these reaction charts plastered on his wall. Every time I'd bring him coffee, I'd see "Benzene + Br2 =?" with an arrow needing FeBr3. It's etched in my mind, right next to the hospital duty roster.
#exams#study
Jump in to reply — no account needed.