In letters a and b, the "?" is a "-".
Answer:
a. - 1.051 V
Explanation:
In a redox reaction, one substance will oxide (lose electrons) and the other will reduce (gain electrons). The potential of reduction can be calculated by placing a redox reaction with H₂, which has a potential equal to 0.
For a spontaneous reaction, the electrons go from the anode (oxidation) to the cathode (reduction), and then the potential of the cell is the cathode potential lesse the anode potential:
E°cell = E°c - E°a
1.587 = 0.536 - E°a
E°a = 0.536 - 1.587
E°a = -1.051 V
