Bromine reacts with methylbenzene in the dark in the presence of a suitable catalyst to form HBr and compound L, C7H7Br. L is one of three isomers that can form in this reaction.

1. (a)(i)The mechanism for the reaction involves methylbenzene reacting with a Br⁺ ion. This ion is produced when bromine reacts with the catalyst. Complete the equation for the reaction of Br2 with the catalyst. Br2 + ..................................................... → Br⁺ + .....................................................[1]
2. (a)(ii)One of the isomers of L forms in much smaller amounts than the other two isomers. Draw the structure of this isomer and explain why it forms in the smallest amount.[2]
3. (a)(iii)Complete the mechanism in Fig. 8.1 for the reaction between methylbenzene and the Br⁺ ion. Include all relevant curly arrows and charges. [Figure 8.1][3]
4. (b)(i)Chlorobutane and chlorobenzene are added separately to samples of warm aqueous AgNO3. One of the chloro-compounds reacts slowly and the other does not react. Identify the chloro-compound that reacts and describe any observations.[1]
5. (b)(ii)Write two equations to explain any observations in (b)(i).[2]
6. (b)(iii)Explain the difference in reactivity of chlorobutane and chlorobenzene with warm aqueous AgNO3.[2]

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