Question
The standard reduction potential for the Zn2+ (aq) | Zn(s) half cell is 0.76 V. Write the reactions occurring at the electrodes when coupled with standard hydrogen electrode (SHE).
Solution
Zn acts as anode, and SHE acts as cathode
At anode: Zn(s) → Zn2+ (aq) + 2e–
At cathode: 2H+ (aq) + 2e– H2(g)
The net cell reaction is
Zn(s) + 2H+ (aq) → Zn2+ + H2(g)
