Chlorine is one of the elements in Group 17 of the Periodic Table.

1. (a)(i)Describe the colours of the Group 17 elements, chlorine to iodine, at room temperature.[1]
2. (a)(ii)Describe the relative reactivity of the elements chlorine to iodine as oxidising agents.[1]
3. (a)(iii)State what is observed when chlorine reacts with hydrogen.[1]
4. (a)(iv)Explain why the thermal stability of the hydrogen halides decreases down the group.[1]
5. (b)(i)Define free radical.[1]
6. (b)(ii)State the essential condition for chlorine to react with C₂H₆ at room temperature.[1]
7. (b)(iii)Write two equations to show the propagation steps in this reaction. 1 2[2]
8. (c)(i)Identify a reagent and conditions that can be used to convert chlorine to NaClO.[1]
9. (c)(ii)Define disproportionation.[1]
10. (c)(iii)Write numbers in the boxes to balance the equation showing the reaction of propanone with NaClO. CH₃COCH₃ + ☐ NaClO → CHCl₃ + CH₃COONa + ☐ NaOH[1]
11. (c)(iv)Aqueous AgNO₃ dissolved in ethanol reacts with an aqueous solution of CHCl₃. State what is observed in this reaction. Explain your answer.[2]