Benzene reacts with chlorine gas to form chlorobenzene. This reaction can be described as the reaction between benzene molecules and Cl⁺ ions. The Cl⁺ ions are formed by adding a suitable catalyst to the chlorine gas. [Figure 1, 2, 3]

1. (a)Give the name or formula of a catalyst that can be used for this reaction.[1]
2. (b)(i)The movement of a pair of electrons is represented by x in diagram 1. State where this pair of electrons is before step 1 takes place. State where this pair of electrons is after step 1 has taken place.[2]
3. (b)(ii)The movement of another pair of electrons is represented by y in diagram 2. State where this pair of electrons is before step 2 takes place. State where this pair of electrons is after step 2 has taken place.[2]
4. (c)There are six carbon atoms in diagram 2. State how many of these carbon atoms are sp hybridised, sp² hybridised, and sp³ hybridised. sp hybridised sp² hybridised sp³ hybridised[1]
5. (d)Complete the equation for this reaction between benzene and chlorine. C₆H₆ +[1]
6. (e)The mechanism for this reaction is electrophilic substitution. Complete the following sentence. Write formulae in the gaps provided. During this reaction, the electrophile is and a in benzene is substituted by a atom atom.[1]
7. (f)(i)Chloroethane reacts with NaOH(aq). Chlorobenzene does not. Name the mechanism of the reaction that chloroethane undergoes with NaOH(aq), and identify the major organic product that is formed. mechanism major organic product[1]
8. (f)(ii)Explain the difference in reactivity of chloroethane and chlorobenzene when treated with NaOH(aq).[2]

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