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. 2. (a) a A student is required to construct a battery in the form of a galvanic cell using nickel (II) nitrate and cadmium (II) nitrate. Given that a 0.75 M solution of nickel (II) nitrate must be used, what concentration of cadmium nitrate is required to achieve a cell voltage of 0.12 V at 25 °C? (10 marks) Ni" (aq) + 2e → Ni(s) Ered=-0.40 V "(aq) + 2e → Cd(s) Ered=-0.26 V Cd (b) Solvent extraction is being used by a student to separate a naturally occurring triprotic acid, HyA (25g/L) from an organic solution. The procedure involved shaking 75 ml of the solution with 100 mL of water and allowing the mixture to equilibrate in a separatory funnel. The aqueous phase was then titrated in triplicate with 1 M NaOH for which the following titre values were obtained: 14.40 ml., 12.00 mL, 12.10 ml. Calculate the partition coefficient of H;A between the organic solvent and water. Molar mass of the triprotic acid = 321.7 g/mol (10 marks)