1. Which one of the following statements is correct?
A. Fuel cells and galvanic cells produce heat.
B. Fuel cells have inert electrodes whereas galvanic cells do not.
C. Fuel cells have porous electrodes whereas galvanic cells do not.
D. Fuel cells and galvanic cells operate when electrons flow through the electrolyte.

Solution
2. A cell can be considered a secondary cell if
A. it has a continuous supply of reactants.
B. it can operate at different temperatures.
C. the polarity of the electrodes remains unchanged.
D. it can operate as both a galvanic and electrolytic cell.
Solution
3. Below are the half-equations for the lead-acid accumulator cell. The lead-acid accumulator cell can operate as an electrolytic cell.

Which one of the following correctly describes the lead-acid accumulator cell when it is operating as a galvanic cell and when it is operating as an electrolytic cell?

Solution

4. Consider the half-cell equations and their half-cell potentials in the table below.

A galvanic cell contains S₂O₃^2-(aq), SO₃^2-(aq) and OH^-(aq) with a platinum electrode in the first half-cell and Mn³⁺(aq) and Mn²⁺(aq) in the second half-cell.
All solutions are 1M solutions and the cell is at SLC.
The galvanic cell will deliver
A. 2.50 V if the electrode in the second half-cell is Mn(s).
B. 2.50 V if the electrode in the second half-cell is Pt(s).
C. 1.75 V if the electrode in the second half-cell is Mn(s).
D. 1.75 V if the electrode in the second half-cell is Pt(s).

Solution

5. The following reaction takes place in the experimental cell during discharge.

A diagram of the experimental cell is shown below.

a. State the energy transformation that occurs in the experimental cell during discharge. 1 mark

Solution

b. Which reactant is the oxidising agent in the experimental cell during discharge? Use oxidation numbers to justify your answer. 2 marks

Solution

c. i. Write the half-equation for the reaction that occurs in the
C₁₄H₈O₈S₂/C₁₄H₁₀O₈S₂ half-cell during recharge. 1 mark

Solution
ii. State the polarity of the C₁₄H₈O₈S₂/C₁₄H₁₀O₈S₂ half-cell electrode during recharge. 1 mark

Solution

iii. Explain how the polarity of the electrodes is established during recharge to allow the recharge to occur. 2 marks

Solution