Key term
Eduqas A-Level Chemistry A410QS
Formulae and Equations
Basic Ideas About Atoms
Topic overviewRadioactive decay and nuclear equationsBehaviour of α, β and γ radiationHalf-life and radioactive decay calculationsRadiation hazards and the uses of radioisotopesIonisation energy and its variation between elementsSuccessive ionisation energies and electronic structureOrbitals and electron configurations of elements 1 to 36Emission and absorption spectraThe hydrogen spectrum, E = hf and the convergence limit
Chemical Calculations
Topic overviewRelative atomic, isotopic, formula and molecular massPrinciples of the mass spectrometerMass spectra, isotopic abundance and relative atomic massEmpirical and molecular formulaeThe mole, the Avogadro constant and molar massMoles, grams and numbers of particlesConcentration and solubilityMolar volume and gas volume correctionsThe ideal gas equationStoichiometry and reacting quantitiesAcid-base titration calculationsAtom economy, percentage yield and percentage error
Bonding
Solid Structures
The Periodic Table
Topic overviewArrangement of the elements and the s-, p- and d-blocksOxidation and reduction as electron transferTrends across periods and down groupsReactions of Group 2 elements with oxygen, water and steamReactions of the aqueous cations Mg²⁺, Ca²⁺ and Ba²⁺Flame coloursReactivity of Group 1 and Group 2 metalsThermal stability of the Group 2 carbonates and hydroxidesSolubility of the Group 2 hydroxides and sulfatesBasic character of the Group 1 and Group 2 oxides and hydroxidesVolatility of the halogens and their reactions with metalsOxidising power, displacement reactions and the silver nitrate testWater treatment, salt preparation and gravimetric analysis
Simple Equilibria and Acid-Base Reactions
Thermochemistry
Rates of Reaction
The Wider Impact of Chemistry
Organic Compounds
Hydrocarbons
Topic overviewAlkanes and the sigma-bonded frameworkCombustion of alkanes and the use of fossil fuelsFree radical substitution and the photochlorination of alkanesAlkenes and the reactivity of the C=C bondE–Z isomerismElectrophilic addition of bromine to alkenesTests for alkenesMarkovnikov addition of hydrogen bromide and carbocation stabilityCatalytic hydrogenation of alkenesAddition polymerisation
Halogenoalkanes
Topic overviewNucleophilic substitution of primary halogenoalkanesElimination reactions forming alkenesBond polarity, bond enthalpy and the ease of substitutionThe silver nitrate test for halogenoalkanesUses of halogenoalkanes and the regulation of their useCFCs and their effect in the upper atmosphereHeating under reflux
Alcohols and Carboxylic Acids
Topic overviewIndustrial preparation of ethanol from etheneFermentation and the distillation of ethanolBiofuels and the issues they raiseClassifying alcohols as primary, secondary and tertiaryDehydration of alcohols to alkenesOxidation of primary alcohols to aldehydes and carboxylic acidsOxidation of secondary alcohols to ketonesThe dichromate(VI) test for alcoholsCarboxylic acids and the sodium hydrogencarbonate testReactions of carboxylic acids with bases, carbonates and hydrogencarbonatesEsterification and separation by distillation
Instrumental Analysis
Redox and Standard Electrode Potential
Redox Reactions
Chemistry of the P-Block
Topic overviewAmphoteric behaviour of aluminium and leadThe inert pair effect in Groups 3, 4 and 5Electron-deficient compounds and expanded octetsAl₂Cl₆ and donor-acceptor compoundsHexagonal and cubic boron nitrideStability of oxidation states II and IV in Group 4Carbon dioxide and lead(II) oxideBonding in the Group 4 chloridesHydrolysis of the Group 4 chloridesReactions of aqueous lead(II) ionsChlorine with cold and warm aqueous sodium hydroxideBleaching and bactericidal action of chlorine and chlorate(I)Sodium halides with concentrated sulfuric acid
Chemistry of the D-Block Transition Metals
Topic overviewOxidation states of the d-block elementsImportant oxidation states and the colours of aqueous ionsBonding in tetrahedral and octahedral complexesThe origin of colour and the splitting of d-orbitalsLigand exchange and change of coordination numberColours and formulae of copper and cobalt complex ionsHeterogeneous and homogeneous catalysisNickel in hydrogenation and iron in the Haber processVanadium(V) oxide and manganese(IV) oxide as catalystsReactions of Cr³⁺, Fe²⁺, Fe³⁺ and Cu²⁺ with excess aqueous hydroxide
Chemical Kinetics
Enthalpy Changes for Solids and Solutions
Entropy and Feasibility of Reactions
Equilibrium Constants
Acid-Base Equilibria
Topic overviewThe Lowry–Brønsted theory and conjugate pairsStrong and weak acids and the dissociation constant KaThe ionic product of water, KwpH of strong acids and strong basespH of weak acids from Ka and pKaTitration curvesHow buffer solutions workBuffer calculationsBuffers in living systems and industrySalt hydrolysis and the choice of indicator
Stereoisomerism
Aromaticity
Alcohols and Phenols
Aldehydes and Ketones
Topic overviewPreparing aldehydes and ketones by oxidation of alcoholsDistinguishing aldehydes and ketones with Tollens’ reagent and Fehling’s solutionReduction of aldehydes and ketones using NaBH₄Nucleophilic addition of HCN to aldehydes and ketonesReaction with 2,4-dinitrophenylhydrazineThe triiodomethane (iodoform) test
Carboxylic Acids and Their Derivatives
Topic overviewRelative acidity of carboxylic acids, phenols, alcohols and waterPreparing carboxylic acids by oxidationReduction and decarboxylation of carboxylic acidsAcid chlorides and their reactionsEsters and their hydrolysisAmides and their hydrolysisNitriles from carboxylic acids and halogenoalkanesHydroxynitriles, hydrolysis and reduction of nitriles
Amines
Amino Acids, Peptides and Proteins
Organic Synthesis and Analysis
Topic overviewPlanning a multi-step synthesisChoosing between alternative routesManipulation and separation techniquesPurification and melting temperatureAddition and condensation polymerisationPolyesters and polyamidesHigh resolution proton NMRCombining spectra to elucidate a structureInterpreting chromatographic dataGas chromatography and HPLC
Specified Practical Work
Topic overviewGravimetric analysis and qualitative analysis of unknown solutionsStandard solutions, standardising an acid and preparing a soluble saltBack titration and double titrationDetermining enthalpy changes by calorimetryFollowing a rate by gas collection, the iodine clock and reaction orderElectrochemical cells, redox titration and the estimation of copperDetermining an equilibrium constant and following a titration with a pH probeHydrolysis of 1-bromobutane and the preparation of an esterOrganic synthesis, purification and identification
Practical Skills and Techniques
Topic overviewChoosing apparatus and recording measurementsVolumetric technique with pipette, burette and volumetric flaskTitration procedure and the choice of indicatorHeating, heating under reflux and distillationFiltration, purification and qualitative testingMelting temperature, chromatography and electrochemical cellsVariables, errors and risk in evaluating a method
Mathematical Skills in Chemistry
Topic overviewStandard form, units and significant figuresRatios, fractions and percentagesChanging the subject and substituting valuesLogarithms, pH and pKaExponentials, the Arrhenius equation and rateGraphs, gradients and interceptsTangents and rates of changeArea under a curveUncertainty and combining errorsThe gas equation and equilibrium expressions
Redox and Standard Electrode Potential
- 5 subtopics
- 15 things to know
- Component 1
What Redox and Standard Electrode Potential covers
Redox and Standard Electrode Potential is examined in Component 1, Physical and Inorganic Chemistry, and drawn on again in Component 3. It covers redox systems and half-equations in cell diagrams, standard electrode potential and the standard hydrogen electrode, combining electrodes to form electrochemical cells, cell EMF and the feasibility of reactions and the hydrogen fuel cell.
Where it is assessed
Component 1
Physical and Inorganic Chemistry, and drawn on again in Component 3.
Check the Eduqas specification ↗The 5 subtopics
Each one has its own page.
- Redox systems and half-equations in cell diagramsRecall questions on what a redox system is, which side the electrons appear on in an oxidation and in a reduction half-equation, the conventions of a cell diagram including the single and double vertical lines, and writing the diagram for a named cell.Open →
- Standard electrode potential and the standard hydrogen electrodeStandard electrode potential of a half-cell, standard conditions used when an electrode potential is measured and how a standard hydrogen electrode is assembled.Open →
- Combining electrodes to form electrochemical cellsMetal/metal ion electrode, electrode based on two oxidation states of the same element and how a half-cell for the MnO₄⁻/Mn²⁺ system is set up.Open →
- Cell EMF and the feasibility of reactionsRecall questions on calculating the cell electromotive force from two standard electrode potentials, what a positive value indicates, predicting whether a proposed reaction will occur, why feasibility says nothing about rate, and worked predictions from a table of potentials.Open →
- The hydrogen fuel cellRecall questions on the reactants and the overall reaction, the electrode reactions in acid and in alkaline conditions, the advantages over a combustion engine, the practical difficulties of storing and producing hydrogen, and both sides of the argument about hydrogen as a fuel.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Explain why the way hydrogen is manufactured weakens the environmental case for fuel cells.
Key term
State the standard conditions used when an electrode potential is measured.
Key term
In a zinc–copper cell, in which direction do electrons travel through the external wire?
Key term
Define the EMF of an electrochemical cell.
Process
In an ion/electron half-equation written for a reduction process, on which side of the arrow do the electrons appear?
Key term
Write the electrode equilibrium for the standard hydrogen electrode.
Key term
Write the overall ionic equation for the reaction that occurs in a zinc–copper cell.
Key term
State the relationship used to obtain a standard cell EMF from two standard electrode potentials.
Key term
Write the overall equation for the reaction in a hydrogen–oxygen fuel cell.
Key term
What is meant by a redox system in the context of a half-cell?
Key term
Why is the platinum foil in a standard hydrogen electrode coated with finely divided platinum black?
Key term
Describe how a half-cell for the MnO₄⁻/Mn²⁺ system is set up.
Numbers
Calculate E⦵cell for the cell Zn(s) | Zn²⁺(aq) ‖ Cu²⁺(aq) | Cu(s), given values of −0.76 V and +0.34 V.
Key term
Write the electrode reaction at the negative electrode of an alkaline hydrogen fuel cell.
Take Redox and Standard Electrode Potential further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
In an ion/electron half-equation written for a reduction process, on which side of the arrow do the electrons appear?
Model answer
The electrons appear on the left-hand side, because the species is gaining them as it is reduced.
- 2
What is meant by a redox system in the context of a half-cell?
Model answer
A redox system is the oxidised and reduced forms of a species present together in one half-cell, linked by a single half-equation.
- 3
Write the half-equation for the reduction of Fe³⁺ ions to Fe²⁺ ions.
Model answer
Fe³⁺(aq) + e⁻ → Fe²⁺(aq).
- 4
Write the half-equation for the oxidation of a magnesium electrode dipping into magnesium sulfate solution.
Model answer
Mg(s) → Mg²⁺(aq) + 2e⁻.
- 5
In a conventional cell diagram, what does a single vertical line stand for?
Model answer
A single vertical line marks a phase boundary, such as the one between a solid electrode and the solution around it.
- 6
In a conventional cell diagram, what does the double vertical line stand for?
Model answer
The double vertical line represents the salt bridge that joins the two half-cells.
What is inside Levo
Six ways to work the same material.
Redox and Standard Electrode Potential revision questions
- What does Redox and Standard Electrode Potential cover in Eduqas A-Level Chemistry?
- 5 subtopics: redox systems and half-equations in cell diagrams, standard electrode potential and the standard hydrogen electrode, combining electrodes to form electrochemical cells, cell emf and the feasibility of reactions and the hydrogen fuel cell. Each one has its own page with questions and model answers.
- How is Redox and Standard Electrode Potential organised?
- By the Eduqas A410QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Redox and Standard Electrode Potential, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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