9 Glossary Redox = oxidation / reduction. Oxidation = the process whereby a species loses its electrons.Reduction = the process whereby a species gains electrons.Electrochemical cell = an array consisting of two electrodes, each of which is in contact with an electrolyte solution. Typically, the two electrolytes are in electrical contact through a salt bridge; an external metal conductor connects the two electrodes.
10 GlossaryElectrode = a conductor at the surface of which electron transfer to or from the surrounding solution takes place.Anode = the electrode at which oxidation occurs.Cathode = the electrode at which reduction occurs.Electrolytes = solute species whose aqueous solutions conduct electricity.Salt bridge = A device that allows conduction of electricity between the two electrolyte solutions while minimizing mixing the two.
11 GlossaryGalvanic cell (voltaic cell) = an electrochemical cell that provides energy during its operation.Electrolytic cell = an electrochemical cell that requires an external energy to drive the cell reaction.Electrode potential (E) = the potential of an electrochemical cell in which the electrode of interest is the right-hand electrode (cathode) and the standard hydrogen electrode is the left-hand electrode (anode) = reduction potential.
12 GlossaryStandard electrode potential (E0) = E when the activity of all reactants and products are unity.Nernst equation = a mathematical expression that relates the potential of an electrode to the activities of those species in solution that are responsible for the potential.Faraday (F) = the quantity of electricity associated with x 1023 electrons.Faradaic current = an electric current produced by oxidation / reduction processes in an electrochemical cell.
13 GlossaryOhmnic potential drop (IR drop) = the potential drop across a cell due to resistance to the movement of charge.Polarization = a phenomenon in which the magnitude of the current is limited by the low rate of the electrode reactions or the slowness of transport of reactants to the electrode surface.Overpotential or overvoltage () = excess voltage necessary to produce current in a polarized electrochemical cell.