Chlorine, Cl₂, is a reactive yellow-green gas. It is a strong oxidising agent.

1. (a)State how Cl₂ is used in water purification.[1]
2. (b)(i)Construct an equation for the first ionisation energy of chlorine. Include state symbols.[1]
3. (b)(ii)Explain the general increase in the first ionisation energies of the Period 3 elements.[2]
4. (c)(i)State and explain the relative thermal stabilities of the hydrogen halides, HX.[2]
5. (c)(ii)Complete the table to show the oxidation number of sulfur in each of the sulfur-containing products.[1]
6. (c)(iii)Explain why different sulfur-containing products are produced when each of these halide ions reacts with concentrated H₂SO₄.[1]
7. (d)(i)State what is meant by disproportionation.[1]
8. (d)(ii)Write an equation for the reaction of Cl₂ with cold aqueous sodium hydroxide.[1]
9. (e)(i)Draw a diagram that clearly shows all the types of bond present in Al₂Cl₆(g).[2]
10. (e)(ii)Describe what you would see when solid aluminium chloride reacts with water. Name the type of reaction that occurs.[2]
11. (f)(i)Suggest the type of bonding and structure shown by ZClₙ.[1]
12. (f)(ii)Calculate the value of n in ZClₙ. n =[2]
13. (g)(i)Give the name of the mechanism of this reaction.[1]
14. (g)(ii)State the essential condition required for the initiation step to take place.[1]
15. (g)(iii)Give the electronic configuration of Cl•. 1s²[1]
16. (g)(iv)Identify the products of the step labelled propagation 2.[1]
17. (g)(v)Name the type of reaction shown in the final step.[1]
18. (g)(vi)Suggest the identity of another organic molecule that is a product of the reaction of CH₃Cl and Cl₂ under the same conditions.[1]

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