Question

In the lead storage battery, lead serves as the anode, and lead coated with lead oxide serves as the cathode. Both electrodes dip into an electrolyte solution of sulfuric acid. The electrode reactions are

Pb(s) + HSO₄(aq) --> PbSO₄(s) + H⁺ (aq) + 2e⁻ Eºox = +0.35V

PbO₂(s) + HSO₄ (aq) + 3H^+(aq) + 2e⁻ --> PbSO₄(s) + 2H₂O(l) Eºred = +1.69V

Cell reaction: Pb(s) + PbO₂(s) + 2HSO₄⁻(aq) + 2H⁺ (aq) --> + 2PbSO₄(s) + 2H₂O(l) (The given standard reduction/oxidation potentials were measured at 25°C).

a. Calculate the standard cell potential, Eº, for this cell at 25°C.

Answer 1

The standard cell potential for the lead storage battery at 25°C is calculated using the reduction potential of the cathode and the oxidation potential of the anode, resulting in E°cell = +1.34 volts.

Step-by-step explanation:

To calculate the standard cell potential for the lead storage battery at 25°C, we can use the standard reduction potentials for the anode and cathode reactions. The oxidation potential of the anode (lead) is given as E°ox = +0.35V, and the reduction potential of the cathode (lead dioxide) is E°red = +1.69V. According to the standard cell potential equation, E°cell is equal to the reduction potential of the cathode minus the oxidation potential of the anode.

Here is the calculation:

E°cell = E°red cathode - E°ox anode

E°cell = (+1.69V) - (+0.35V)

E°cell = +1.34V

Thus, the standard cell potential, E°, for the lead storage battery at 25°C is +1.34 volts, indicating how much voltage the cell can produce under standard conditions. This calculation shows the potential difference driving the flow of electrons from the anode to the cathode during discharge. Since each individual lead storage cell can produce about 2V, arranging six of these in series, as in a typical car battery, allows for a cumulative voltage of approximately 12V, suitable for vehicle operation.