Reaction of galvanic cell
Further explanation
Given
Redox reaction between Zn and Mg
Required
Half reaction
Potential of the cell
Solution
Zn²⁺ + 2e -> Zn E ° = -0.76 V
Mg²⁺ + 2e -> Mg E ° = - 2.37 V
The higher E ° of the cell will act as the positive pole/cathode
Electrode Zn as a cathode (reduction) and Mg as an anode (oxidation) (E ° of Zn cells is greater than Mg)
Half reaction
Cathode: Zn²⁺ + 2e ⇒ Zn E ° = -0.76 V
Anode: Mg ⇒ Mg²⁺ + 2e E ° = +2.37 V
------------------------------------------------- ----------- +
Cell reaction: Zn²⁺ + Mg ---> Zn + Mg²⁺ E ° cell = +1.61 V
The reaction occurs spontaneously in the absence of an electric current, thus including galvanic cells/voltaic cells
