Question

1) Explain what happens during the recharging of the Lead-acid accumulator and write
it's reduction and oxidation reactions
2) Explain what happens during the discharging of the lead-acid accumulator and write
it's anode and cathode reactions

Answer 1

Answer:

Explanation:

1. Some electrochemical cells are rechargeable – the electrode reactions are reversible and the process can be repeated many times. Such cells can be used to store electricity. The most common type of heavy duty rechargeable cell is the familiar lead-acid accumulator (‘car battery’) found in most combustion-engined vehicles.

A simple lead-acid cell consisting of strips of lead and an electrolyte of dilute sulfuric acid is constructed and charged for different lengths of time. The cell is then discharged through a light bulb and the time the bulb remains lit measured. Plotting a graph of this time against the charging time shows the relationship between the electrical energy put into the cell and the energy released.

During charging (electrode signs as in charging circuit)

(+) electrode: PbSO4(s) + 2H2O(l) → PbO2(s) + 4H+(aq) + SO42-(aq) + 2e-

(-) electrode: PbSO4(s) + 2e- → Pb(s) + SO42-(aq)