text stringlengths 2 2.33k | source stringclasses 826
values |
|---|---|
galvanic (voltaic) cell : electrochemical cell in which a spontaneous redox reaction takes place; also called avoltaic cell | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
galvanization : method of protecting iron or similar metals from corrosion by coating with a thin layer of more easily oxidized zinc. | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
half cell : component of a cell that contains the redox conjugate pair (âcoupleâ) of a single reactant | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
inert electrode : electrode that conducts electrons to and from the reactants in a half-cell but that is not itself oxidized or reduced | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
lead acid battery : rechargeable battery commonly used in automobiles; it typically comprises six galvanic cells based on Pb half-reactions in acidic solution | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
lithium ion battery : widely used rechargeable battery commonly used in portable electronic devices, based on lithium ion transfer between the anode and cathode | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
Nernst equation : relating the potential of a redox system to its composition | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
nickel-cadmium battery : rechargeable battery based on Ni/Cd half-cells with applications similar to those of lithium ion batteries | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
primary cell : nonrechargeable battery, suitable for single use only | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
sacrificial anode : electrode constructed from an easily oxidized metal, often magnesium or zinc, used to prevent corrosion of metal objects via cathodic protection | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
salt bridge : tube filled with inert electrolyte solution | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
secondary cell : battery designed to allow recharging | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
standard cell potential(Ecell°)(Ecell°) : the cell potential when all reactants and products are in their standard states (1 bar or 1 atm or gases; 1Mfor solutes), usually at 298.15 K | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
standard electrode potential ((EX°)(EX°)) : electrode potential measured under standard conditions (1 bar or 1 atm for gases; 1Mfor solutes) usually at 298.15 K | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
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 | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-key-terms |
Redox reactions are defined by changes in reactant oxidation numbers, and those most relevant to electrochemistry involve actual transfer of electrons. Aqueous phase redox processes often involve water or its characteristic ions, H+and OHâ, as reactants in addition to the oxidant and reductant, and equations represen... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
Galvanic cells are devices in which a spontaneous redox reaction occurs indirectly, with the oxidant and reductant redox couples contained in separate half-cells. Electrons are transferred from the reductant (in the anode half-cell) to the oxidant (in the cathode half-cell) through an external circuit, and inert soluti... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
The property of potential,E, is the energy associated with the separation/transfer of charge. In electrochemistry, the potentials of cells and half-cells are thermodynamic quantities that reflect the driving force or the spontaneity of their redox processes. The cell potential of an electrochemical cell is the differen... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
Potential is a thermodynamic quantity reflecting the intrinsic driving force of a redox process, and it is directly related to the free energy change and equilibrium constant for the process. For redox processes taking place in electrochemical cells, the maximum (electrical) work done by the system is easily computed f... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
Galvanic cells designed specifically to function as electrical power supplies are called batteries. A variety of both single-use batteries (primary cells) and rechargeable batteries (secondary cells) are commercially available to serve a variety of applications, with important specifications including voltage, size, an... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
Spontaneous oxidation of metals by natural electrochemical processes is called corrosion, familiar examples including the rusting of iron and the tarnishing of silver. Corrosion process involve the creation of a galvanic cell in which different sites on the metal object function as anode and cathode, with the corrosion... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
Nonspontaneous redox processes may be forced to occur in electrochemical cells by the application of an appropriate potential using an external power sourceâa process known as electrolysis. Electrolysis is the basis for certain ore refining processes, the industrial production of many chemical commodities, and the el... | https://openstax.org/books/chemistry-atoms-first-2e/pages/16-summary |
relative reaction rates for a A ⶠb B = â 1 a Î [ A ] Î t = 1 b Î [ B ] Î t relative reaction rates for a A ⶠb B = â 1 a Î [ A ] Î t = 1 b Î [ B ] Î t | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
integrated rate law for zero-order reactions: [ A ] t = â k t + [ A ] 0 , [ A ] t = â k t + [ A ] 0 , | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
half-life for a zero-order reaction t 1 / 2 = [ A ] 0 2 k t 1 / 2 = [ A ] 0 2 k | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
integrated rate law for first-order reactions: ln [ A ] t = â k t + ln [ A ] 0 , ln [ A ] t = â k t + ln [ A ] 0 , | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
half-life for a first-order reaction t 1 / 2 = 0.693 k t 1 / 2 = 0.693 k | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
integrated rate law for second-order reactions: 1 [ A ] t = k t + 1 [ A ] 0 , 1 [ A ] t = k t + 1 [ A ] 0 , | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
half-life for a second-order reaction t 1 / 2 = 1 [ A ] 0 k t 1 / 2 = 1 [ A ] 0 k | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
k = A e â E a / R T k = A e â E a / R T | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
ln k = ( â E a R ) ( 1 T ) + ln A ln k = ( â E a R ) ( 1 T ) + ln A | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
ln k 1 k 2 = E a R ( 1 T 2 â 1 T 1 ) ln k 1 k 2 = E a R ( 1 T 2 â 1 T 1 ) | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-equations |
activated complex : (also, transition state) unstable combination of reactant species formed during a chemical reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
activation energy (Ea) : minimum energy necessary in order for a reaction to take place | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
Arrhenius equation : mathematical relationship between a reactionâs rate constant, activation energy, and temperature | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
average rate : rate of a chemical reaction computed as the ratio of a measured change in amount or concentration of substance to the time interval over which the change occurred | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
bimolecular reaction : elementary reaction involving two reactant entities | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
catalyst : substance that increases the rate of a reaction without itself being consumed by the reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
collision theory : model that emphasizes the energy and orientation of molecular collisions to explain and predict reaction kinetics | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
elementary reaction : reaction that takes place in a single step, precisely as depicted in its chemical equation | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
frequency factor (A) : proportionality constant in the Arrhenius equation, related to the relative number of collisions having an orientation capable of leading to product formation | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
half-life of a reaction (tl/2) : time required for half of a given amount of reactant to be consumed | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
heterogeneous catalyst : catalyst present in a different phase from the reactants, furnishing a surface at which a reaction can occur | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
homogeneous catalyst : catalyst present in the same phase as the reactants | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
initial rate : instantaneous rate of a chemical reaction att= 0 s (immediately after the reaction has begun) | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
instantaneous rate : rate of a chemical reaction at any instant in time, determined by the slope of the line tangential to a graph of concentration as a function of time | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
integrated rate law : equation that relates the concentration of a reactant to elapsed time of reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
intermediate : entities produced in one step of a reaction mechanism and consumed in a subsequent step | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
method of initial rates : common experimental approach to determining rate laws that involves measuring reaction rates at varying initial reactant concentrations | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
molecularity : number of reactant entities involved in an elementary reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
overall reaction order : sum of the reaction orders for each substance represented in the rate law | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
rate constant (k) : proportionality constant in a rate law | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
rate expression : mathematical representation defining reaction rate as change in amount, concentration, or pressure of reactant or product species per unit time | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
rate law : (also, rate equation) (also, differential rate laws) mathematical equation showing the dependence of reaction rate on the rate constant and the concentration of one or more reactants | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
rate of reaction : measure of the speed at which a chemical reaction takes place | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
rate-determining step : (also, rate-limiting step) slowest elementary reaction in a reaction mechanism; determines the rate of the overall reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
reaction diagram : used in chemical kinetics to illustrate various properties of a reaction | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
reaction mechanism : stepwise sequence of elementary reactions by which a chemical change takes place | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
reaction order : value of an exponent in a rate law (for example, zero order for 0, first order for 1, second order for 2, and so on) | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
termolecular reaction : elementary reaction involving three reactant entities | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
unimolecular reaction : elementary reaction involving a single reactant entity | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-key-terms |
The rate of a reaction can be expressed either in terms of the decrease in the amount of a reactant or the increase in the amount of a product per unit time. Relations between different rate expressions for a given reaction are derived directly from the stoichiometric coefficients of the equation representing the react... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
The rate of a chemical reaction is affected by several parameters. Reactions involving two phases proceed more rapidly when there is greater surface area contact. If temperature or reactant concentration is increased, the rate of a given reaction generally increases as well. A catalyst can increase the rate of a reacti... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
Rate laws (differential rate laws) provide a mathematical description of how changes in the concentration of a substance affect the rate of a chemical reaction. Rate laws are determined experimentally and cannot be predicted by reaction stoichiometry. The order of reaction describes how much a change in the concentrati... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
Integrated rate laws are mathematically derived from differential rate laws, and they describe the time dependence of reactant and product concentrations. | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
The half-life of a reaction is the time required to decrease the amount of a given reactant by one-half. A reactionâs half-life varies with rate constant and, for some reaction orders, reactant concentration. The half-life of a zero-order reaction decreases as the initial concentration of the reactant in the reaction... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
Chemical reactions typically require collisions between reactant species. These reactant collisions must be of proper orientation and sufficient energy in order to result in product formation. Collision theory provides a simple but effective explanation for the effect of many experimental parameters on reaction rates. ... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
The sequence of individual steps, or elementary reactions, by which reactants are converted into products during the course of a reaction is called the reaction mechanism. The molecularity of an elementary reaction is the number of reactant entities involved, typically one (unimolecular), two (bimolecular), or, less co... | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
Catalysts affect the rate of a chemical reaction by altering its mechanism to provide a lower activation energy, but they do not affect equilibrium. Catalysts can be homogenous (in the same phase as the reactants) or heterogeneous (a different phase than the reactants). | https://openstax.org/books/chemistry-atoms-first-2e/pages/17-summary |
acid anhydride : compound that reacts with water to form an acid or acidic solution | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
alkaline earth metal : any of the metals (beryllium, magnesium, calcium, strontium, barium, and radium) occupying group 2 of the periodic table; they are reactive, divalent metals that form basic oxides | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
allotropes : two or more forms of the same element, in the same physical state, with different chemical structures | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
amorphous : solid material such as a glass that does not have a regular repeating component to its three-dimensional structure; a solid but not a crystal | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
base anhydride : metal oxide that behaves as a base towards acids | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
bicarbonate anion : salt of the hydrogen carbonate ion,HCO3âHCO3â | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
bismuth : heaviest member of group 15; a less reactive metal than other representative metals | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
borate : compound containing boron-oxygen bonds, typically with clusters or chains as a part of the chemical structure | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
carbonate : salt of the anionCO32â;CO32â;often formed by the reaction of carbon dioxide with bases | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
chemical reduction : method of preparing a representative metal using a reducing agent | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
chlor-alkali process : electrolysis process for the synthesis of chlorine and sodium hydroxide | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
disproportionation reaction : chemical reaction where a single reactant is simultaneously reduced and oxidized; it is both the reducing agent and the oxidizing agent | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
Downs cell : electrochemical cell used for the commercial preparation of metallic sodium (and chlorine) from molten sodium chloride | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
Frasch process : important in the mining of free sulfur from enormous underground deposits | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
Haber process : main industrial process used to produce ammonia from nitrogen and hydrogen; involves the use of an iron catalyst and elevated temperatures and pressures | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
halide : compound containing an anion of a group 17 element in the 1â oxidation state (fluoride, Fâ; chloride, Clâ; bromide, Brâ; and iodide, Iâ) | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
HallâHéroult cell : electrolysis apparatus used to isolate pure aluminum metal from a solution of alumina in molten cryolite | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydrogen carbonate : salt of carbonic acid, H2CO3(containing the anionHCO3â)HCO3â)in which one hydrogen atom has been replaced; an acid carbonate; also known asbicarbonate ion | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydrogen halide : binary compound formed between hydrogen and the halogens: HF, HCl, HBr, and HI | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydrogen sulfate : HSO4âHSO4âion | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydrogen sulfite : HSO3âHSO3âion | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydrogenation : addition of hydrogen (H2) to reduce a compound | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
hydroxide : compound of a metal with the hydroxide ion OHâor the group âOH | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
interhalogen : compound formed from two or more different halogens | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
metal (representative) : atoms of the metallic elements of groups 1, 2, 12, 13, 14, 15, and 16, which form ionic compounds by losing electrons from their outersorporbitals | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
metalloid : element that has properties that are between those of metals and nonmetals; these elements are typically semiconductors | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
nitrate : NO3âNO3âion; salt of nitric acid | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
nitrogen fixation : formation of nitrogen compounds from molecular nitrogen | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
Ostwald process : industrial process used to convert ammonia into nitric acid | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
oxide : binary compound of oxygen with another element or group, typically containing O2âions or the group âOâ or =O | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
ozone : allotrope of oxygen; O3 | https://openstax.org/books/chemistry-atoms-first-2e/pages/18-key-terms |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.