Consider the electrolytic procedure for purifying copper. Suppose that a sample of copper contains the following impurities Fe, Ag, Zn, Au, Co, Pt, and PbWhich of the following changes occur during this process?

Ag, Au and Pt are noble metals, remain unaffected during electrolytic refining of copper and comes into anode mud. Fe, Zn, Co and Pb are oxidized and dissolve in electrolyte Ag, Au and Pt can be recovered from anode mud.