2. The electrochemical cell without liquid junction is shown below. It consists of a zinc amalgam electrode and a silver-silver chloride electrode in a solution of zinc chloride. Zine decide 4 As E Perde Znot Zn Amalgam Figure adapted from (Chemistry Practical IV manual) The complete cell can be represented as follows:- Zn(Hg)/ZnCl2(m)/AgCl/Ag The electromotive force emf, E, of the cell is given by the following equation E = E RT In 4m 8+ 2F where m = concentration of ZnCl2 solution 84 = mean activity coefficient E = standard emf of the cell Part A: Emf of the cell at different concentrations of ZnCl2 solution is present in the table below. Concentration of ZnCl2, m Emf, v 0.003 1.1060 0.005 1.1068 0.008 1.1080 0.010 1.1095 0.100 1.2000 (a) Write the half-cells and full cell reaction of the above electrochemical cell. (b) Calculate the measured emf, Emand ionic strength, 1, for all concentrations of the ZnCl2 solution if Em = E 3RT -b1 2F (c) From the result obtained in (1b), determine standard emf, E, and the constant b at 25 C. (12 marks) Part B: At 25 C, Ag/AgCl, ZnCl2(0.1000m)//ZnCl2(0.0050m)AgCl/Ag 3RT (M8) E = t+ In 2F (m82.) Given: E = 0.0250 V, 0+ (0.1000 m ZnCl2) = 2.118 x 10, 0 (0.0050 mZnCl2) = 0.3761, F = 96500 C molt (a) Write the half cell and full cell reaction. (b) (i) Calculate transport number, t-, of Zne at 25C and 30 C using the data given. (m) Comment on your answer in (bi). (8 marks)