Chapter 16, Problem 115E

Which of your group’s cells do you think would produce the largest voltage? Why?

A promising technology based on a redox reaction is the direct methanol fuel cell. Instead of hydrogen, it uses liquid methanol, ${\text{CH}}_3\text{OH}$, as a fuel. The unbalanced reaction is ${\text{CH}}_3\text{OH}+{\text{O}}_2\to {\text{CO}}_{\text{2}}+{\text{H}}_{\text{2}}\text{O}$.

a. Assign oxidation states to each atom in the reaction.

b. Determine what is being oxidized and what is being reduced.

c. Write and balance the separate half-reactions. (Hint: Methanol reacts to form carbon dioxide, and oxygen reacts to form water.)

d. Balance the overall reaction if it occurs in acidic solution.

e. Methanol fuel cells must be designed to allow ${\text{H}}^{+}$ to pass from one electrode to the other. Do they start at the electrode with the methanol or at the electrode with the oxygen? How do you know?