Sketch a voltaic cell for each redox reaction. Label the anode and cathode and indicate the half-reaction that occurs at each electrode and the species present in each solution. Also indicate the direction of electron flow.
a. 2 Ag+(aq) + Pb(s) → 2 Ag(s) + Pb2+(aq)
b. 2 ClO2(g) + 2 I–(aq) → 2 ClO2–(aq) + I2(s)
c. O2(g) + 4 H+(aq) + 2 Zn(s) → 2 H2O(l) + 2 Zn2+(aq)