Chapter 7 - Chemical Equilibrium

Reaction Gibbs energy - The slope of the graph of the Gibbs energy plotted against the extent of the reaction.

Exergonic - Since the process is spontaneous, it can be used to drive another process, such as another reaction, or used to do non-expansion work.
Endergonic - The reaction can be made to occur only by doing work on it, such as electrolyzing water to reverse its spontaneous formation reaction.

Standard reaction Gibbs energy - The difference in the standard molar Gibbs energies of the reactants and products.

Thermodynamic equilibrium constant - An equilibrium constant K expressed in terms of activities.

Le Chatelier's principle - A system at equilibrium, when subjected to a disturbance, responds in a way that tends to minimize the effect of the disturbance.

Exothermic reactions - Increased temperature favors the reactants.
Endothermic reactions - Increased temperature favors the products.
Van 't Hoff equation - An expression for the slope of a plot of the equilibrium constant as a function of temperature. It can be expressed in two ways:

Electrodes - Metallic conductors.
Electrolyte - An ionic conductor.
Salt bridge - A tube containing a concentrated electrolyte solution that completes the electrical circuit and enables the cell to function.
Galvanic cell - An electrochemical cell that produces electricity as a result of the spontaneous reaction occurring inside it.
Electrolytic cell - An electrochemical cell in which a non-spontaneous reaction is driven by an external source of current.

Oxidation - The removal of electrons from a species.
Reduction - The addition of electrons to a species.
Redox reaction - Reaction in which there is a transfer of electrons from one species to another.
Reducing agent (Reductant) - The electron donor.
Oxidizing agent (Oxidant) - The electron acceptor.
Redox couple - The reduced and oxidized species in a half-reaction.
Anode - The electrode at which oxidation occurs.
Cathode - The electrode at which reduction occurs.

Electrolyte concentration cell - The electrode compartments are identical except for the concentrations of the electrolytes.
Electrode concentration cell - When the electrodes themselves have different concentrations, either because they are gas electrodes operating at different pressures or because they are amalgams with different concentrations.
Liquid junction potential - An additional source of potential difference across the interface of the two electrolytes.

Cell reaction - The reaction in the cell written on the assumption that the right-hand electrode is the cathode.

Standard hydrogen electrode - The specially selected electrode.
Standard potential - The right-hand electrode and the standard hydrogen electrode is the left-hand electrode.

Electrochemical series - The metallic elements arranged in the order of their reducing power as measured by their standard potentials in an aqueous solution.

Ion-selective electrode - An electrode that generates a potential in response to the presence of a solution of specific ions.
Gas-sensing electrode - Consists of a glass electrode contained in an outer sleeve filled with an aqueous solution and separated from the test solution by a membrane that is permeable to gas.
Asymmetry potential - Observed even when the activity of the test species is the same on both sides of the membrane.