GLOBAL KNOWLEDGE ARK

Reference library

Foundations

Explore concepts, laws, equations and methods, with clear explanations of their use and sources. Choose an area of study or find a specific entry.

More filters

Reference entries

Showing 241–270 of 1709 reference entries

Physics · Earth & cosmosNuclear binding energy

A bound nucleus has less rest mass than its separated nucleons.

ModelPhysics · Earth & cosmosExponential radioactive decay

A fixed decay probability per time gives a population timescale.

ModelPhysics · Earth & cosmosFission, fusion and reaction energy

Nuclear rearrangement can release or require energy.

ModelPhysicsScattering cross section

Normalize a scattering rate by incident flux.

ModelPhysicsStandard Model matter families

Quarks and leptons form three generations.

ModelPhysicsStandard Model interactions

Gauge fields mediate three interactions; the Higgs is a scalar sector.

ModelPhysicsInteraction-specific quantum-number balances

A balance rule must name the interaction where it applies.

ModelPhysics · ChemistryBloch states and electronic bands

A periodic crystal potential organizes energies by wavevector and band.

ModelPhysics · ChemistrySemiconductor electrons and holes

Band occupancy and doping control mobile carriers.

ModelPhysicsBose and Fermi thermal occupations

Indistinguishable particles have different equilibrium state populations.

ModelChemistryElectron screening and effective nuclear attraction

Other electrons modify the attraction experienced by an electron in an atom.

ModelChemistryMultielectron ground-state configurations

Orbital occupations connect atomic electronic structure with valence chemistry.

ModelChemistryLocalized bonds and resonance descriptions

Localized orbital overlap and resonance are complementary chemical descriptions.

ModelChemistryMolecular orbitals and bonding occupation

A molecular orbital description distributes electronic states across a molecule.

ModelChemistryIntermolecular interactions

Dispersion, dipole interactions and hydrogen bonding influence molecular materials.

ModelChemistryBonding classes of solids

Ionic, metallic, molecular and network solids organize common bonding patterns.

DefinitionChemistryPolymers and macromolecular architecture

Polymers are substances composed of macromolecules with recurring structural units.

DefinitionChemistryCoordination compounds and ligands

Ligand donor atoms surround a central metal in a coordination sphere.

DefinitionChemistryActivities and chemical potentials

Activity expresses composition relative to a specified thermodynamic standard state.

DefinitionChemistrypH and hydrogen-ion activity

pH is an activity-based quantity realized through measurement conventions.

DefinitionChemistryBuffers and finite buffering capacity

An acid–base pair can resist limited changes in solution pH.

ModelChemistrySolubility products and precipitation

An equilibrium product constrains dissolution of a specified solid phase.

ModelChemistryReference electrodes and redox potentials

Electrode potentials are specified relative to a reference half-cell.

DefinitionChemistryThe Nernst equilibrium relation

Reversible electrochemical potential depends on activities and temperature.

ModelChemistryElementary steps and reaction mechanisms

A mechanism proposes steps that account for an overall chemical transformation.

ModelChemistryArrhenius temperature dependence

Many rate constants follow an exponential temperature model over a limited range.

ApproximationChemistryHess's law and thermochemical accounting

Reaction enthalpies can be combined because enthalpy is a state function.

ModelChemistryPhase diagrams and coexistence

Phase diagrams describe equilibrium states under stated conditions.

ModelChemistryCalibration, standards and matrix effects

Quantitative analysis needs a validated relation between response and analyte amount.

MethodChemistryChromatographic retention and separation

Differential interactions with mobile and stationary phases separate mixture components.

Method
DefinitionSource checked

Reference electrodes and redox potentials

Chemistry

Electrode potentials are specified relative to a reference half-cell.

Key knowledge

An electrode potential compares a redox half-cell with a chosen reference. Consistently tabulated reduction potentials give a cell's standard potential as the cathode value minus the anode value. Potentials measure driving force per charge, not reaction speed.

Conditions and scope

  • Specify temperature, reaction direction and standard states; standard does not inherently mean one fixed temperature.
  • An individual half-cell potential cannot be measured without a reference and a complete measurement arrangement.
Sources · 1

References

Sources retain their recorded scope. A source link alone does not establish verification of every statement.

  1. Chemistry 2e, 17.3: Electrode and Cell PotentialsPaul Flowers, Klaus Theopold, Richard Langley and William R. Robinson — OpenStax, Rice UniversityTextbook chapteropenstax.orgRead source

Evidence and review

Source reference-electrode and cell-potential conventions.

2026-10-10 · Checked sign convention and reference scope; no cell construction or performance promise.

Related reference entries

Explore relationships within this area of study and its connections to other areas.

Showing 1–6 of 6 relationships

Scientific relationships · 6 / 6

The relationship type describes the connection. Its linked statements, sources and conditions define the scope.

  1. Related to
    Relationship sources · 1

    Linked statements

    • The Nernst equation relates a reversible cell potential to its standard potential, temperature and reaction quotient. It follows from the thermodynamic relations between reaction Gibbs energy and reversible electrical work; it does not include current-dependent voltage losses.

    Reaction conditions modify a reversible cell's standard potential.

  2. Related to
    Relationship sources · 1

    Linked statements

    • Groundwater exchanges dissolved species with aquifer minerals and surfaces. Dissolution, sorption and redox conditions affect mobility; residence and flow paths affect observed composition. Natural and introduced constituents require the same explicit chemical and hydrologic accounting.

    Redox environment can alter species stability.

  3. Related to
    Relationship sources · 1

    Linked statements

    • Valence occupation and electronic stabilization organize main-group chemistry: alkali metals commonly form +1 ions and alkaline-earth metals +2 ions, while p-block elements support varied covalent structures and oxidation states. Heavier p-block elements can stabilize lower oxidation states associated with an inert-pair pattern.

    A redox tendency also depends on the specified medium and states.

  4. Related to
    Relationship sources · 2

    Linked statements

    • Oxide O²−, peroxide O₂²− and superoxide O₂− contain different numbers and arrangements of oxygen atoms and electrons. Sulfur can occur as elemental rings, reduced sulfides and oxidized oxygen-containing compounds. Structure and oxidation state distinguish these species and their acid/base or redox chemistry; sharing a periodic group does not make their compounds interchangeable.

    Reaction conditions determine redox driving forces.

  5. Related to
    Relationship sources · 2

    Linked statements

    • Halogens and halides have distinct oxidizing and reducing roles; for example, chlorine can oxidize bromide under suitable solution conditions. Chlorine in water can disproportionate into hypochlorous-acid and chloride forms. Xenon fluorides such as XeF2, XeF4 and XeF6 demonstrate that a filled atomic valence shell does not prohibit compound formation.

    Conditional redox potentials constrain conversion.

  6. Related to
    Relationship sources · 1

    Linked statements

    • Oxidation states assign electrons formally rather than measuring atomic partial charge. A pure element has oxidation state zero, a monatomic ion's value equals its charge, and the sum over atoms in a chemical species equals its total charge. Increasing an atom's oxidation state is oxidation; decreasing it is reduction. Coupled half-reaction accounting preserves both atoms and total charge.

    Reversible potential measures a reaction's driving force with its medium specified.

Entry detailsPermanent link to this entry ↗
Record identity
chem-redox-potentials
Revision
university-reference.1
Structured reference record
University reference