Final answer:
The student’s reaction is not representative of common chemical processes with lead sulfate. Instead, the redox reactions during the recharge of a lead-acid battery are relevant, involving lead, lead dioxide, and sulfate species. These reactions theoretically allow infinite recharging, though practical limitations exist due to inefficiencies.
Step-by-step explanation:
The reaction presented by the student, PbSO4 yielding PbSO3 + O2, does not accurately describe a common chemical process. However, considering the context of lead-acid batteries, the chemical reaction of interest typically involves the reduction and oxidation (redox) processes that occur during the recharging of the battery. These processes can be represented as follows:
- The anode (oxidation): Pb(s) + SO42-(aq) → PbSO4(s) + 2e−
- The cathode (reduction): PbO2(s) + 4H+(aq) + SO42-(aq) + 2e− → PbSO4(s) + 2H2O(l)
Combining these half-reactions gives the overall cell reaction during recharge:
2PbSO4(s) + 2H2O(l) → Pb(s) + PbO2(s) + 2H2SO4(aq)
This reaction regenerates the lead, lead (IV) oxide, and sulfuric acid that are necessary for the operation of the battery. In theory, a lead-acid battery could operate indefinitely due to these reversible reactions, but in practice, the process is less efficient and some of the lead sulfate may leave the electrodes and collect at the bottom of the battery’s cells.