20. Electrochemistry
Electroplating
47PRACTICE PROBLEM
Iridium is an impurity found in a mixture of palladium and silver metals that have undergone electrorefining. The oxidation state of iridium is Ir3+ and its standard reduction potential is as follows:
Ir3+(aq) + 3 e– → Ir(s) E°red = 1.156 V
Using this information, what is likely to happen to iridium impurities during electrorefining? When palladium is oxidized, do the impurities remain at the bottom of the refining bath (unchanged) or do they dissolve as ions? If they dissolve in the solution, will they plate out on the cathode?
Pd2+(aq) + 2 e– → Pd(s) E°red = 0.951
Iridium is an impurity found in a mixture of palladium and silver metals that have undergone electrorefining. The oxidation state of iridium is Ir3+ and its standard reduction potential is as follows:
Ir3+(aq) + 3 e– → Ir(s) E°red = 1.156 V
Using this information, what is likely to happen to iridium impurities during electrorefining? When palladium is oxidized, do the impurities remain at the bottom of the refining bath (unchanged) or do they dissolve as ions? If they dissolve in the solution, will they plate out on the cathode?
Pd2+(aq) + 2 e– → Pd(s) E°red = 0.951