Question

1 – Balance the following

1. Bi(OH)₃ + SnO₂^2- → SnO₃^2- + Bi                                             in basic solution
2. Mn²⁺ + BiO₃^- → Bi³⁺ + MnO₄^-                                                                 in acidic solution

2 – Describe the basic features of a galvanic cell and explain why the two components are separated from each other.

3 – Calculate the standard potential of a cell that uses a Mg/Mg²⁺ half-cell and a Cu/Cu²⁺ half-cell. Identify the oxidizing agent.

4 – What is the equilibrium constant for the cell referenced in problem 3?

5 – If a hydrogen fuel cell runs an electric motor drawing a current of 8.5 A for 3.0 h, what volume of H₂(g) is needed if the fuel is stored at 155 atm and 25 °C? (Ideal gas law required. Assume H₂ behaves as an ideal gas under these conditions.)

6 – Chromium plating can be applied by electrolysis to objects according to the following unbalanced half-reaction:

                Cr₂O₇^2- + e^- + H⁺ → Cr(s) + H₂O

How long (in hours) would it take to apply a chromium plating 0.010 mm thick to a car bumper with a surface area of 0.25 m² in a cell with a current of 25.0 A? The density of chromium is 7.19 g/cm³.

Answer 1