Subjects
| Sections | |||
|---|---|---|---|
| Redox Reaction | 32 mins | 0 completed | Learn Summary |
| Balancing Redox Reaction | 31 mins | 0 completed | Learn |
| The Nernst Equation | 11 mins | 0 completed | Learn |
| Faraday's Constant | 10 mins | 0 completed | Learn |
| Galvanic Cell | 85 mins | 0 completed | Learn |
| Batteries and Electricity | 9 mins | 0 completed | Learn |
| Additional Practice |
|---|
| Cell Notation |
| Standard Hydrogen Electrode |
| Cell Potential |
| Electroplating |
| Electrolysis of Water & Mixture of Ions |
| Additional Guides |
|---|
| Nernst Equation |
The following reactions are used in batteries:
I. 2H2(g) + O2(g) ⟶ 2H2O(l) Ecell = 1.23 V
II. Pb(s) + PbO2(s) + 2H2SO4(aq) ⟶ 2PbSO4(s) + 2H2O(l) Ecell = 2.04 V
III. 2Na(l) + FeCl2(s) ⟶ 2NaCl(s) + Fe(s) Ecell = 2.35 V
Reaction I is used in fuel cells, II in the automobile lead-acid battery, and III in an experimental high-temperature battery for powering electric vehicles. The aim is to obtain as much work as possible from a cell, while keeping its weight to a minimum.
(b) Calculate the ratio, in kJ/g, of wmax to mass of reactants for each of the cells. Which has the highest ratio, which the lowest, and why? (Note: For simplicity, ignore the masses of cell components that do not appear in the cell as reactants, including electrode materials, electrolytes, separators, cell casing, wiring, etc.)