Electrodes and electrochemical cells
Well, here we are four chapters into this book and already at the heart of electrochemistry. In this chapter you will learn what happens when two electronic conductors (the electrodes) are brought together in a solution containing ions (the electrolyte). You already know a lot about the effect of a huge lump of metal on a bunch of ions, but now we are going to allow those ions or species in solution to do more than set up double layers or simply adsorb. The essence of electrochemistry is that many species react at conductors in solution, gaining or losing electrons. If this is allowed to happen, currents flow: electron currents in the wires connecting the electrodes, and ion currents in the electrolyte. Even if no current flows, the fact that all this chemistry is poised and about to happen manifests itself as a voltage that can be measured across the cell.
Unable to display preview. Download preview PDF.