Describe the electrophilic addition reaction of propene with Br2/CCl4, including the formation of the bromonium ion.

5 (a)

iii)
The reaction of compound E ($\text{CH}_3\text{CH}=\text{CH}_2$, propene) with $\text{Br}_2/\text{CCl}_4$ is an electrophilic addition reaction.

Step 1: The $\pi$ electrons of the alkene attack one bromine atom, forming a cyclic bromonium ion and releasing a bromide ion.

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