Question

(i) Write the cell reactions taking place during the discharge of the lead storage battery.

Hint:

The lead storage battery is rechargeable, making it widely used in automobiles and inverters.

Answer 1

Step 1: Introduction to Lead Storage Battery - The lead storage battery is a secondary battery that can be recharged.
- It consists of lead (Pb) as the anode and lead dioxide (PbO\(_2\)) as the cathode, immersed in sulfuric acid (H\(_2\)SO\(_4\)) electrolyte. 

Step 2: Cell Reactions During Discharge 

Anode Reaction (Oxidation): \[ \text{Pb (s)} + \text{SO}_4^{2-} (aq) \rightarrow \text{PbSO}_4 (s) + 2e^- \] 

Cathode Reaction (Reduction): \[ \text{PbO}_2 (s) + 4H^+ (aq) + \text{SO}_4^{2-} (aq) + 2e^- \rightarrow \text{PbSO}_4 (s) + 2H_2O (l) \]

 Overall Cell Reaction: \[ \text{Pb} (s) + \text{PbO}_2 (s) + 4H^+ (aq) + 2\text{SO}_4^{2-} (aq) \rightarrow 2\text{PbSO}_4 (s) + 2H_2O (l) \]

 Step 3: Working Principle - During discharge, Pb and PbO\(_2\) get converted into PbSO\(_4\), releasing electrical energy.
- During charging, the reaction is reversed, regenerating Pb and PbO\(_2\).