When a lead storage battery is discharged

Options

A. `PbSO_(4)` is formed
B. Pb is formed
C. `SO_(2)` is consumed
D. `H_(2)SO_(4)` is consumed

Answer

### Step-by-Step Text Solution:

1. **Understanding the Lead Storage Battery**:
- A lead storage battery, also known as a lead-acid battery, is a type of rechargeable battery. It consists of lead plates and lead dioxide plates submerged in an electrolyte solution of sulfuric acid (H2SO4).

2. **Discharge Process**:
- During the discharge of a lead storage battery, chemical reactions occur that convert the stored chemical energy into electrical energy. The reactions take place at the anode and cathode.

3. **Anode Reaction**:
- At the anode (negative plate), lead (Pb) is oxidized to lead sulfate (PbSO4). The half-reaction can be represented as:
\[ \text{Pb} \rightarrow \text{PbSO}_4 + 2\text{e}^- \]

4. **Cathode Reaction**:
- At the cathode (positive plate), lead dioxide (PbO2) is reduced to lead sulfate (PbSO4). The half-reaction can be represented as:
\[ \text{PbO}_2 + 4\text{H}^+ + 2\text{e}^- \rightarrow \text{PbSO}_4 + 2\text{H}_2\text{O} \]

5. **Overall Reaction**:
- The overall reaction during the discharge of the lead storage battery combines the two half-reactions:
\[ \text{PbO}_2 + \text{Pb} + 2\text{H}_2\text{SO}_4 \rightarrow 2\text{PbSO}_4 + 2\text{H}_2\text{O} \]

6. **Consumption of Electrolyte**:
- As the battery discharges, sulfuric acid (H2SO4) is consumed, and lead sulfate (PbSO4) and water (H2O) are produced.

7. **Conclusion**:
- Therefore, during the discharge of a lead storage battery, lead and lead dioxide are converted into lead sulfate, and sulfuric acid is consumed in the process.