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

17081 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

Explain why the enthalpy of lattice dissociation of potassium oxide is less endothermic than that of sodium oxide.


How can aldehydes and ketones be distinguished?


State and explain the trend in boiling points of chlorine, bromine, and iodine


What is a mole and why is it useful?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences