# Why do acids favor the oxidizer? And bases the reducer?

Simply put, why does adding acid to the cathode up the cell voltage? From what I understand, acids are proton donors. Do these positive protons attract electrons toward the cathode compartment of the electrochemical cell?

The effect that can be observed by adding acids to a solution to increase conductivity is known as the Grotthuss mechanism. Protons have a much higher mobility in solution ($3.62\cdot10^{-3}~\mathrm{cm^2~V^{-1}~s^{-1}}$) than any other cation, basically allowing it to tunnel through a solution. (A similar effect can be noted for hydroxyl anions.) Basically this allows a much faster charge exchange through hydrogen bond networks, also resulting in a higher cell voltage.