An electrochemical cell is constructed using two half-cells. : a Br2/Br- half-cell an Mn³+/Mn2+ half-cell

1. (a)State the material used for the electrode in each half-cell. Br2/Br- half-cell Mn3+/Mn2+ half-cell[1]
2. (b)(i)Use the Nernst equation to calculate the electrode potential, E, of the Mn³+/Mn2+ half-cell under these conditions. E =[2]
3. (b)(ii)Calculate the Ecell under these conditions. Ecell[1]
4. (b)(iii)Write an equation for the overall cell reaction that occurs.[2]
5. (c)An aqueous solution of copper(II) sulfate is electrolysed using copper electrodes. A current of 1.50A is passed for 3.00 hours. 5.09 g of copper is deposited on the cathode. The charge on one electron is −1.60 × 10–19 С. The relative atomic mass of copper is 63.5. Use these data to calculate an experimentally determined value for the Avogadro constant, L. Give your answer to three significant figures. L =[5]
6. (d)Explain why magnesium metal cannot be obtained by the electrolysis of dilute aqueous magnesium sulfate. Your answer should include data from the Data Booklet.[2]