Gen Chem Key Terms Ch. 19 (after Acid-Base Titrations) to Ch. 21 (including Nernest Equation)单词卡 | Quizlet

buffer capacity

A measure of the ability of a buffer to resist a change in pH; related to the total concentrations and relative proportions of buffer components.

buffer range

The pH range over which a buffer acts effectively.

common-ion effect

The shift in the position of an ionic equilibrium away from an ion involved in the process that is caused by the addition or presence of that ion.

complex ion

An ion consisting of a central metal ion covalently bonded to two or more anions or molecules, called ligands.

formation constant (Kf)

An equilibrium constant for the formation of a complex ion from the hydrated metal ion and ligands.

Henderson-Hasselbalch equation

An equation for calculating the pH of a buffer system

ligand

A molecule or an anion bonded to a central metal ion in a complex ion.

selective precipitation

The process of separating ions through differences in the solubility of their compounds with a given precipitating ion.

solubility-product constant (Ksp)

An equilibrium constant for a slightly soluble ionic compound dissolving in water.

adenosine triphosphate (ATP)

A high-energy molecule that serves most commonly as a store and source of energy in organisms.

coupling of reactions

The pairing of reactions of which one releases enough free energy for the other to occur.

entropy (S)

A thermodynamic quantity related to the number of ways the energy of a system can be dispersed through the motions of its particles.

free energy (G)

A thermodynamic quantity that is the difference between the system’s enthalpy and the product of the absolute temperature and the system’s entropy: G = H − TS.

microstate

An instantaneous, quantized state of a system of particles throughout which the total energy of the system is dispersed.

second law of thermodynamics

A law stating that a process occurs spontaneously in the direction that increases the entropy of the universe.

spontaneous change

A change that occurs under specified conditions without an ongoing input of external energy.

standard entropy of reaction (ΔS°rxn)

The entropy change that occurs when all components are in their standard states.

standard free energy change (ΔG°)

The free energy change that occurs when all components of a system are in their standard states.

standard free energy of formation (ΔGf°)

The standard free energy change that occurs when 1 mol of a compound is made from its elements with all components in their standard states.

standard molar entropy (S°)

The entropy of 1 mol of a substance in its standard state.

third law of thermodynamics

A law stating that the entropy of a perfect crystal is zero at 0 K.

ampere (A)

The SI unit of electric current; 1 ampere of current results when 1 coulomb of charge flows through a conductor in 1 second.

anode

The electrode at which oxidation occurs in an electrochemical cell. Electrons are given up by the reducing agent and leave the cell at the anode.

battery

A group of voltaic cells arranged in series; primary and secondary types are self-contained, but flow batteries are not.

cathode

The electrode at which reduction occurs in an electrochemical cell. Electrons enter the cell and are acquired by the oxidizing agent at the cathode.

cell potential (Ecell)

(also electromotive force, or emf; cell voltage) The difference in electrical potential between the two electrodes of an electrochemical cell.

concentration cell

A voltaic cell in which both compartments contain the same components but at different concentrations.

corrosion

The natural redox process that results in unwanted oxidation of a metal.

coulomb (C)

The SI unit of electric charge. One coulomb is the charge of 6.242 × 1018 electrons; one electron possesses a charge of 1.602 × 10−19 C.

electrochemical cell

A system that incorporates a redox reaction to produce or use electrical energy.

electrochemistry

The study of the relationship between chemical change and electrical work.

electrode

The part of an electrochemical cell that conducts the electricity between the cell and the surroundings.

electrolysis

The nonspontaneous lysing (splitting) of a substance, often to its component elements, by the input of electrical energy.

electrolyte

A mixture of ions, in which the electrodes of an electrochemical cell are immersed, that conducts a current.

electrolytic cell

An electrochemical system that uses electrical energy to drive a nonspontaneous chemical reaction (ΔG > 0).

Faraday constant (F)

The physical constant representing the charge of 1 mol of electrons: F = 96,485 C/mol e−.

fuel cell

(also flow battery) A battery that is not self-contained and in which electricity is generated by the controlled oxidation of a fuel.

half-cell

A portion of an electrochemical cell in which a half-reaction takes place.

half-reaction method

A method of balancing redox reactions by treating the oxidation and reduction half-reactions separately.

Nernst equation

An equation stating that the voltage of an electrochemical cell under any conditions depends on the standard cell voltage and the concentrations of the cell components:

salt bridge

An inverted U tube containing a solution of nonreacting ions that connects the compartments of a voltaic cell and maintains neutrality by allowing ions to flow between compartments.

standard cell potential (E°cell)

The potential of a cell measured with all components in their standard states and no current flowing.

standard electrode potential (E°half-cell)

(also standard half-cell potential) The standard potential of a half-cell, with the half-reaction written as a reduction.

standard hydrogen electrode

A specially prepared platinum electrode immersed in 1 M H+(aq) through which H2 gas at 1 atm is bubbled. E Half-Cell is defined as 0 V.

volt (V)

The SI unit of electrical potential: 1 V = 1 J/C.

voltaic cell

(also galvanic cell) An electrochemical cell that uses a spontaneous redox reaction to generate electrical energy.

voltage

Here textbook says "see cell potential", which is "The difference in electrical potential between the two electrodes of an electrochemical cell."