Iron is extracted in a blast furnace. The raw materials required are • iron ore, which contains iron(III) oxide, Fe2O3, • limestone, • coke (carbon), • air.

1. (a)(i)The coke first burns in air to form carbon dioxide. The carbon dioxide is then reduced by coke to produce carbon monoxide. The carbon monoxide reduces the iron(III) oxide to iron. Write equations for the reduction of carbon dioxide by coke,[1]
2. (a)(ii)the reduction of iron(III) oxide to iron by carbon monoxide.[1]
3. (b)Why is limestone added to the blast furnace?[1]
4. (c)Another ore of iron contains an oxide with the formula Fe3O4· Calculate the percentage by mass of iron in Fe3O4.[2]
5. (d)Iron can be obtained by the electrolysis of an aqueous acidified solution of iron(II) sulfate. The reactions at the electrodes are given. at the anode (positive electrode): 4OH- → O2 + 2H2O + 4e- at the cathode (negative electrode): Fe2+ + 2e- → Fe Which reaction is oxidation and which is reduction? Explain your answer.[2]
6. (e)Attaching magnesium strips to the iron hulls of ships can lower their rate of rusting. Explain how the magnesium stops the iron from rusting.[2]
7. (f)Aqueous iron(II) chloride is one of the products formed when iron reacts with hydrochloric acid. Construct an equation for this reaction.[1]