When a measured cell voltage is negative, the electrode to which the red lead is attached is actually the anode rather than the cathode (i. e., you should enter a positive voltage). The anode is the electrode at which oxidation takes place, so it is surrendering electrons to the external circuit. For the two cells involving the iron and copper species, the Cu(II)/Cu(s) couple is the anode. Which of the following half-cell reactions is taking place at the Cu electrode in the anode compartment of these two cells?