COMEDK · Chemistry · 18. Electrochemistry
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 | \(Pb + 2SO_4^{2-} + 4H^+ + 2e^- \to PbSO_4 + 2H_2O + SO_2\) |
| Leclanche Cell | Cathode | \(MnO_2 + NH_4^+ + 2e^- \to MnO + OH + NH_3\) |
| Mercury Cell | Anode | \(Zn/Hg + 2OH^- \to ZnO(s) + H_2O + 2e^-\) |
| Fuel Cell | Cathode | \(O_2(g) + 2H_2O + 4e^- \to 4OH^-\) |
- A A & B
- B C & D
- C A & C
- D B & D
Answer & Solution
Correct Answer
(A) A & B
Step-by-step Solution
Detailed explanation
In a lead-storage cell, the cathode reaction involves the reduction of lead dioxide to lead sulfate: \(\mathrm{PbO}_2 + \mathrm{SO}_4^{2-} + 4\mathrm{H}^+ + 2\mathrm{e}^- \rightarrow \mathrm{PbSO}_4 + 2\mathrm{H}_2\mathrm{O}\). The reaction given in the table for the…
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