This question is about the chlorides of the elements in Period 3.

1. (a)State the electronic configuration of the positive ion in sodium chloride, NaCl.[1]
2. (b)(i)Magnesium chloride crystals can be prepared by reacting an insoluble base with an acid. Name an insoluble base and the acid that can be used. insoluble base ........................................................................................ acid ....................................................................................................[1]
3. (b)(ii)Describe the essential practical details for the preparation of pure magnesium chloride crystals.[3]
4. (c)(i)Anhydrous aluminium chloride contains 20.2% by mass of aluminium. Show that the empirical formula for anhydrous aluminium chloride is AlCl3.[2]
5. (c)(ii)A sample of anhydrous aluminium chloride has a mass of 2.34 g. The sample contains 0.00876 mol of anhydrous aluminium chloride. Calculate the relative molecular mass and give the molecular formula for anhydrous aluminium chloride. relative molecular mass ............................................................................ molecular formula ..................................................................................[2]
6. (d)Silicon(IV) chloride, SiCl4, has a simple molecular structure. Predict one physical property of silicon(IV) chloride at room temperature.[1]