6 3 This question is about aluminium chloride. (a) Complete the electronic configuration of an aluminium atom. (1) 1s2 ………………………………………………………………………………………………………………………… (b) At high temperatures, aluminium chloride exists as AlCl3 molecules. (i) Draw a dot-and-cross diagram of an aluminium chloride molecule, AlCl3. Show the outer shell electrons only. (1) (ii) Predict the shape of an AlCl3 molecule and the Cl−Al−Cl bond angle. (2) Shape of AlCl3 Cl−Al−Cl bond angle Turn over 7 (iii) Aluminium chloride is used as a catalyst in the alkylation of benzene. Draw the mechanism for the reaction between benzene and chloromethane using aluminium chloride as the catalyst. Include an equation for the formation of the electrophile, and any relevant curly arrows. (4) (c) Aluminium chloride exists as a dimer, Al2Cl6 , just above its boiling temperature. (i) Draw a diagram to show how two AlCl3 molecules are joined together in the dimer. (1) (ii) State the type of bond that joins the two AlCl3 molecules together. (1) .................................................................................................................................................................................................................................................................................... (Total for Question 3 = 10 marks)