Copper electrorefining is a major industrial electrochemical process. The electrolyte for electrorefining of Cu is composed of: 50gl1H2SO4 and 12gl1CuSO4 [1]. At the cathode two parallel reactions can take place: a ) Cu electrodeposition (the desired, primary reaction) and b)H2(g) evolution (undesired, secondary reaction). For Cu deposition at 50C the exchange current density is: 25Am2 and the transfer coefficient is 0.34 [1]. For H2 evolution it has been reported that the exchange current density is 8104Am2 at 25C and the transfer coefficient is 0.5 [2]. Calculate the following: Copper electrodeposition is performed at constant current densities of 200,300,400 500,650 and 800Am2 and 1 atm pressure. Assume the following: i) mixed control for Cu deposition with a mass transfer limiting current density of 696Am2[1], ii) pure electrode kinetic control for H2 evolution, iii) each 10C increase of the temperature doubles the exchange current density for H2 evolution. Note: the mass transfer limiting current density has been measured in a flow cell where the electrolyte was circulated with a flow rate of 450mlmin. Calculate the current efficiency for Cu electrodeposition (i.e. current used by the primary reaction per total current, where the total current density is primary plus secondary). Calculate and plot the Cu deposition overpotential. Comment briefly on your results