Iodine is an element in Group 17 of the Periodic Table. (a) (i) At room temperature, iodine solid has a lattice structure. Describe the arrangement of the iodine molecules within the solid. [1] (ii) List all of the forces of attraction present in solid iodine and identify which of these are overcome when solid iodine is heated to produce iodine vapour. force(s) of attraction present force(s) of attraction overcome [2] Iodine reacts with aluminium to form a white solid, Al2I6. (b) The diagram shows the arrangement of the outer electrons within a molecule of Al2I6. [Figure 2.1 showing a molecule of Al2I6 with iodide and aluminium atoms and XX representing shared electron pairs] (i) How many co-ordinate (dative covalent) bonds are made when a molecule of Al2I6 is formed from its atoms? [1] (ii) Describe how co-ordinate (dative covalent) bonds form within this molecule. [1] (c) In a reaction between hydrogen iodide and concentrated sulfuric acid, the products are hydrogen sulfide, sulfur, iodine and water. (i) Write an equation for this reaction. You may wish to use oxidation numbers to help you. [2] (ii) Explain, with reference to oxidation numbers, why this reaction is a redox reaction. [2] [Total: 9]