Without a catalyst, an alkene will react with bromine while benzene will not. Why is this?

The pi-bonds in benzene are delocalised over the entire ring, while in an alkene the pi-bonds are only delocalised over two carbon atoms. This means that benzene has a lower charge denisity than an alkene so benzene doesn't particularly polarise the bromine molecule. So no electrophilic addition between the bromine and benzene will take place.

The larger charge denisty of the alkene will mean that as the bromine molecule approaches the alkene it is polarised, the alkene can then donate its electrons to the positive bromide ion.

JT
Answered by Jack T. Chemistry tutor

18415 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

What is entropy and how is it used in chemistry?


Suggest why Phenol is more reactive than Benzene in Electrophillic Substitution


What is chirality/optical isomerism?


Describe and explain the electrical conductivity of lithium oxide, Li2O, and lithium in their solid and molten states.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning