Solution Found!
Consider a fuel cell that uses methane (“natural gas”) as
Chapter 5, Problem 5P(choose chapter or problem)
Consider a fuel cell that uses methane (“natural gas”) as fuel. The reaction is
CH4 + 2O2 → 2H2O + CO2
(a) Use the data at the back of this book to determine the values of ΔH and ΔG for this reaction, for one mole of methane. Assume that the reaction takes place at room temperature and atmospheric pressure.
(b) Assuming ideal performance, how much electrical work can you get out of the cell, for each mole of methane fuel?
(c) How much waste heat is produced, for each mole of methane fuel?
(d) The steps of this reaction are
at – electrode: CH4 + 2H2O → CO2 + 8H+ + 8e–;
at + electrode: 2O2 + 8H+ + 8e– → 4H2O.
What is the voltage of the cell?
Questions & Answers
QUESTION: Problem 5P
Consider a fuel cell that uses methane (“natural gas”) as fuel. The reaction is
CH4 + 2O2 → 2H2O + CO2
(a) Use the data at the back of this book to determine the values of ΔH and ΔG for this reaction, for one mole of methane. Assume that the reaction takes place at room temperature and atmospheric pressure.
(b) Assuming ideal performance, how much electrical work can you get out of the cell, for each mole of methane fuel?
(c) How much waste heat is produced, for each mole of methane fuel?
(d) The steps of this reaction are
at – electrode: CH4 + 2H2O → CO2 + 8H+ + 8e–;
at + electrode: 2O2 + 8H+ + 8e– → 4H2O.
What is the voltage of the cell?
ANSWER:
Step 1 of 7
(a)
Consider, 
The change in the enthalpy can be given as,
