1. Using data in Appendix E, calculate the standard emf for each of the following reactions:
(a) H2(g) + F2(g) → 2 H+(aq) + 2 F-(aq)
(b) Cu2+(aq) + Ca(s) → Cu(s) + Ca2+(aq)
(c) 3 Fe2+(aq) → Fe(s) + 2 Fe3+(aq)
(d) 2 ClO3-(aq) + 10 Br-(aq) + 12 H+(aq) → Cl2(g) + 5 Br2(l) + 6 H2O(l)
2. Using the standard reduction potentials listed in Appendix E, calculate the equilibrium constant for each of the following reactions at 298 K:
(a) Cu(s) + 2 Ag+(aq) → Cu2+ (aq) + 2 Ag(s)
(b) 3 Ce4+(aq) + Bi(s) + H2O(l) → 3 Ce3+(aq) + BiO+(aq) + 2 H+(aq)
(c) N2H5+(aq) + 4 Fe(CN)63-(aq) → N2(g) + 5 H+(aq) + 4 Fe(CN)64-(aq)
3. A voltaic cell is constructed with two silver-silver chloride electrodes, each of which is based on the following half-reaction:
AgCl(s) + e- → Ag(s) + Cl-(aq)
The two half-cells have [Cl-] = 0.0150 M and [Cl-] = 2.55 M, respectively. (a) Which electrode is the cathode of the cell? (b) What is the standard emf of the cell? (c) What is the cell emf for the concentrations given? (d) For each electrode, predict whether [Cl-] will increase, decrease, or stay the same as the cell operates.
This solution offers succinct guidelines for solving a set of numerical problems on voltaic cell EMF.