Chapter 23.6, Problem 23.13P

At several points in the electron transport chain, iron cations gain or lose electrons by reactions that interconvert ${\text{Fe}}^{\text{2+}}$ and ${\text{Fe}}^{\text{3+}}$ cations. (a) When ${\text{Fe}}^{\text{3+}}$ is converted to ${\text{Fe}}^{\text{2+}},$ is the reaction an oxidation or a reduction? (b) Is ${\text{Fe}}^{\text{3+}}$ an oxidizing agent or a reducing agent?