Electrochemistry Flashcards
Galvanic (Voltaic) Cells
Electrochemical cell in which a spontaneous redox reaction takes place
Half-Cells
Components of a cell that contain the redox conjugate pair (“couple”) of a single reactant
Anode
Electrode in an electrochemical cell at which oxidation occurs
Cathode
Electrode in an electrochemical cell at which reduction occurs
Salt Bridge
Tube filled with inert electrolyte solution
Cell Notation (Schematic)
Symbolic representation of the components and reactions in an electrochemical cell
Inert Electrode
Electrode that conducts electrons to and from the reactants in a half-cell but that is not itself oxidized or reduced
Active Electrode
Electrode that participates as a reactant or product in the oxidation-reduction reaction of an electrochemical cell; the mass of an active electrode changes during the oxidation-reduction reactions
Cell Potentials (E cell)
Difference in potential of the cathode and anode half-cells
Standard Cell Potentials (E* cell)
The cell potential when all reactants and products are in their standard states (1 bar or 1 atm for gases; 1 M for solutes), usually at 298.15K
Standard Hydrogen Electrode (SHE)
Half-cell based on hydrogen ion production, assigned a potential of exactly 0 V under standard state conditions, used as the universal reference for measuring electrode potential
Electrode Potential (Ex)
The potential of a cell in which the half-cell of interest acts as a cathode when connected to the standard hydrogen electrode
Standard Electrode Potential (E* x)
Electrode potential measured under standard conditions (1 bar or 1 atm for gases; 1 M for solutes) usually at 298.15K
Faraday’s Constant
Charge on 1 mol of electrons; F = 96,485 C/mol e^-
Nernst Equation
Relating the potential of a redox system to its composition
Battery
Single or series of galvanic cells designed for use as a source of electrical power
Primary Cells
Nonrechargeable battery, suitable for single use only
Secondary Cells
Battery designed to allow recharging
Dry Cell
Primary batter, also called a zinc-carbon battery, based on the spontaneous oxidation of zinc by manganese(IV)
Lithium Ion Batteries
Widely used rechargeable battery commonly used in portable electronic devices, based on lithium ion transfer between the anode and cathode
Lead Acid Battery
Rechargeable battery commonly used in automobiles; it typically comprises six galvanic cells based on Pb half-reactions in acidic solution
Fuel Cell (Flow Battery)
Devices similar to galvanic cells that require a continuous feed of redox reactants
Corrosion
Degradation of metal via a natural electrochemical process
Galvanization
Method of protecting iron or similar metals from corrosion by coating with a thin layer of more easily oxidized zinc