Consider the Fig. 3.2 and answer the following questions.
(i) Cell ‘A’ has ECell = 2V and Cell ‘B’ has ECell = 1.1V which of the two cells ‘A’ or ‘B’ will act as an electrolytic cell. Which electrode reactions will occur in this cell?
(ii) If cell ‘A’ has ECell = 0.5V and cell ‘B’ has ECell = 1.1V then what will be the reactions at anode and cathode?
(i) Given,
ECell(A) = 2V
ECell(B) = 1.1V
• The electrolytic cell with small Ecell will act as an electrolytic cell. Therefore, Cell B with lower emf value will act as an electrolytic cell.
• The half-cell reactions are:
• Anode: Cu(S)→ Cu2+ + 2e-
• Cathode: Zn2+ + 2e-→ Zn(S)
(ii) Given,
ECell(A) = 0.5V
ECell(B) = 1.1V
• Cell B having higher emf value will behave as a galvanic cell.
• Thus, new half-cell reactions are:
• Anode: Zn(S)→ Zn2+ + 2e-
• Cathode: Cu2+ + 2e-→ Cu(S)