Identify the two incorrect electrochemical reactions shown as taking place in the given cells at the respective electrodes. Cell Electrode Reaction Lead-Storage Cell Cathode Pb + 2SO₄²⁻ + 4H^+ + 2e^- PbSO₄ + 2H₂O + SO₂ Leclanche Cell Cathode MnO₂ + NH₄^+ + 2e^- MnO + OH + NH₃ Mercury Cell Anode Zn/Hg + 2OH^- ZnO(s) + H₂O + 2e^- Fuel Cell Cathode O₂(g) + 2H₂O + 4e^- 4OH^-

Step-by-step solution

In a lead-storage cell, the cathode reaction involves the reduction of lead dioxide to lead sulfate: PbO ₂ + SO ₄²⁻ + 4 H ^+ + 2 e ^- PbSO ₄ + 2 H ₂ O . The reaction given in the table for the lead-storage cell cathode is incorrect as it shows Pb instead of PbO ₂ and includes SO ₂ . In a Leclanche cell, the cathode reaction involves the reduction of manganese dioxide: 2 MnO ₂ + 2 NH ₄^+ + 2 e ^- Mn ₂ O ₃ + 2 NH ₃ + H ₂ O . The reaction given in the table is incorrect as it shows MnO and OH instead of the standard p