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
Thermochemistry
- 5 subtopics
- 15 things to know
- Components 1 and 2
What Thermochemistry covers
Thermochemistry is examined in Components 1 and 2, since the Core Ideas are examined on both written papers, and drawn on again in Component 3. It covers enthalpy changes of reaction, combustion and formation, Hess's law and energy cycles, average bond enthalpies, Calculating enthalpy changes from experimental data and laboratory procedures for determining enthalpy changes.
Where it is assessed
Components 1 and 2
the Core Ideas, Principles and Concepts, which are examined on both written papers and drawn on again in Component 3.
Check the Eduqas specification ↗The 5 subtopics
Each one has its own page.
- Enthalpy changes of reaction, combustion and formationEnthalpy change of a reaction, standard conditions used when a standard enthalpy change is quoted and standard enthalpy change of combustion.Open →
- Hess's law and energy cyclesRecall questions on the statement of Hess's law, constructing an energy cycle from enthalpies of formation and from enthalpies of combustion, the direction of each arrow, worked calculations both ways, and why an indirect route gives the same answer as the direct one.Open →
- Average bond enthalpiesBond enthalpy and units in which bond enthalpies are quoted.Open →
- Calculating enthalpy changes from experimental dataRecall questions on q = mcΔT and what each symbol means, which mass is used in a solution reaction, converting the heat change to a molar enthalpy change, the sign convention, and worked combustion, neutralisation and dissolving calculations checked in both directions.Open →
- Laboratory procedures for determining enthalpy changesRecall questions on the calorimetry apparatus and method, the polystyrene cup and its insulation, why the temperature is extrapolated back to the moment of mixing, the main sources of error, and why a spirit burner determination falls short of the accepted value.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Numbers
Give the relationship used to calculate the heat energy transferred to a measured mass of water.
Key term
Describe how the enthalpy change of neutralisation is measured in the laboratory.
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State the standard conditions used when a standard enthalpy change is quoted.
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State Hess's law.
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Write the equation, with state symbols, whose enthalpy change is the standard enthalpy change of formation of water.
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Why is Hess's law useful for a reaction that cannot be carried out directly?
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What is meant by bond enthalpy?
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State the value of the specific heat capacity of water normally used in calorimetry calculations, with its units
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What two masses must be recorded in a simple combustion experiment?
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Write the equation, with state symbols, whose enthalpy change is the standard enthalpy change of combustion of ethanol.
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What must be done to an enthalpy change when the equation it belongs to is reversed?
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Why are bond enthalpies always positive?
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Why can a temperature change be substituted in either degrees Celsius or kelvin?
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Name the largest single source of error in a simple combustion calorimetry experiment.
Take Thermochemistry further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by the enthalpy change of a reaction?
Model answer
It is the heat energy taken in or given out when a reaction occurs at constant pressure.
- 2
What sign does the enthalpy change of an exothermic reaction carry, and why?
Model answer
It is negative, because the products hold less energy than the reactants and heat is released to the surroundings.
- 3
What sign does the enthalpy change of an endothermic reaction carry, and why?
Model answer
It is positive, because the products hold more energy than the reactants and heat is absorbed from the surroundings.
- 4
State the standard conditions used when a standard enthalpy change is quoted.
Model answer
A pressure of 100 kPa and a stated temperature, normally 298 K, with all substances in their standard states and any solutions at a concentration of 1 mol dm⁻³.
- 5
What does the superscript symbol ϴ attached to an enthalpy change indicate?
Model answer
It indicates that the value refers to the reaction carried out under standard conditions.
- 6
Define the standard enthalpy change of combustion.
Model answer
It is the enthalpy change when one mole of a substance is burned completely in oxygen under standard conditions.
What is inside Levo
Six ways to work the same material.
Thermochemistry revision questions
- What does Thermochemistry cover in Eduqas A-Level Chemistry?
- 5 subtopics: enthalpy changes of reaction, combustion and formation, hess's law and energy cycles, average bond enthalpies, calculating enthalpy changes from experimental data and laboratory procedures for determining enthalpy changes. Each one has its own page with questions and model answers.
- How is Thermochemistry organised?
- By the Eduqas A410QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Thermochemistry, 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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