Chapter 17, Problem 17.138MP

Experimental solid-oxide fuel cells that use butane (C₄H₁₀) as the fuel have been reported recently. These cells contain composite metal/metal oxide electrodes and a solid metal oxide electrolyte. The cell half-reactions are

 Anode:    C₄H₁₀(g) + 13 O^2– (s) → 4 CO₂(g) + 5 H₂O(l) + 26 e^–

Cathode:    O₂(g) + 4e^–→ 2 O^2–(s)

1. (a) Write a balanced equation for the cell reaction.
2. (b) Use the thermodynamic data in Appendix B to calculate the values of E° and the equilibrium constant K for the cell reaction at 25 °C. Will E° and K increase, decrease, or remain the same on raising the temperature?
3. (c) How many grams of butane are required to produce a constant current of 10.5 A for 8.00 h? How many liters of gaseous butane at 20 °C and 815 mm Hg pressure are required?