Write a balanced equation for the overall cell reaction when a lead storage battery is being charged. Refer to Section 19.10.

Verified step by step guidance

1. Identify the half-reactions involved in the lead storage battery during charging. The lead storage battery consists of a lead dioxide (PbO2) cathode and a lead (Pb) anode, with sulfuric acid (H2SO4) as the electrolyte.
2. Write the oxidation half-reaction. During charging, lead sulfate (PbSO4) at the anode is converted back to lead (Pb) and sulfate ions (SO4^{2-}). The half-reaction is: \[ \text{PbSO}_4 (s) + 2e^- \rightarrow \text{Pb} (s) + \text{SO}_4^{2-} (aq) \]
3. Write the reduction half-reaction. At the cathode, lead sulfate (PbSO4) is converted back to lead dioxide (PbO2), water (H2O), and sulfate ions (SO4^{2-}). The half-reaction is: \[ \text{PbSO}_4 (s) + 2H_2O (l) \rightarrow \text{PbO}_2 (s) + 4H^+ (aq) + 2e^- + \text{SO}_4^{2-} (aq) \]
4. Combine the two half-reactions to form the overall balanced equation. Ensure that the electrons are balanced and cancel out in the overall reaction.
5. Simplify the equation by combining like terms and ensuring that all atoms and charges are balanced. The final balanced equation represents the overall cell reaction during the charging of a lead storage battery.

Key Concepts

Redox Reactions

Redox reactions involve the transfer of electrons between two species, resulting in oxidation (loss of electrons) and reduction (gain of electrons). In the context of a lead storage battery, the charging process is a redox reaction where lead sulfate is converted back to lead and lead dioxide, restoring the battery's charge.

Electrochemical Cells

Electrochemical cells convert chemical energy into electrical energy through redox reactions. In a lead storage battery, the cell consists of two electrodes (lead and lead dioxide) immersed in an electrolyte solution. Understanding the structure and function of these cells is crucial for writing balanced equations for their reactions.

Balancing Chemical Equations

Balancing chemical equations ensures that the number of atoms for each element is the same on both sides of the equation, adhering to the law of conservation of mass. This process involves adjusting coefficients to achieve balance, which is essential when writing the overall cell reaction for the charging of a lead storage battery.