1. Predict the potential for the following voltaic cell at 25 C:
Cu(s)|CuSO4(1.09 M)||AgNO3(0.43 M)|Ag(s)
(Answer must be in volts)
2. Suppose a 4-volt battery is delivering a steady current of 4 A for a period of 2 hours. Calculate the total charge in coulombs that passes through this circuit.
( answer must be in coulombs )
3. Use a table of standard thermodynamic values to predict the standard cell potential at 55 C:
Cu(s)|CuSO4||AgNO3|Ag(s)
Assume that the values of ΔH and ΔS are independent of temperature.
( answer must be in volts )
4. A steel railroad bridge uses a zinc sacrificial anode to limit the extent of oxidation of the steel. If a 9.7 kg anode is completely ozidized to Zn2+ over the course of 16.2 years, compute the average current flowing through the anode.
(answer must be in Amperes )
5. Someday, cars may be powered by clean H2/O2 fuel cells and electric motors. Under standard conditions, such a fuel cell can develop 1.229 volts. If the oxygen is obtained from air (at P=0.21 bar), what pressure of H2 would be required to develop 1.228 volts from the cell at 25 C?
(answer must be in bar )
6. At 25 C, the standard hydrogen electrode (SHE) has a half-cell potential that is defined to be 0.00 volts. If the pH is increased at this electrode (keeping everything else the same), at what pH will the half-cell potential be equal to -0.244 volts?
7. Two standard reduction potentials for an unknown metal oxide are:
MO2+ → MO+ E0=0.1035 v
MO2+ → M2+ E0=0.161 v
Complete the reduction potential diagram for this system by calculating the standard half-cell reduction potential for MO+ → M2+
(answer must be in volts )