Numbers
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
Chemical Calculations
- 12 subtopics
- 36 things to know
- Components 1 and 2
What Chemical Calculations covers
Chemical Calculations 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 relative atomic, isotopic, formula and molecular mass, principles of the mass spectrometer, mass spectra, isotopic abundance and relative atomic mass, empirical and molecular formulae, the mole, the Avogadro constant and molar mass, moles, grams and numbers of particles, concentration and solubility, molar volume and gas volume corrections, the ideal gas equation, stoichiometry and reacting quantities, acid-base titration calculations and atom economy, percentage yield and percentage error.
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 12 subtopics
Each one has its own page.
- Relative atomic, isotopic, formula and molecular massRelative atomic mass, relative isotopic mass and relative molecular mass.Open →
- Principles of the mass spectrometerHow a sample is ionised by electron impact and quantity m/z.Open →
- Mass spectra, isotopic abundance and relative atomic massRecall questions on reading a mass spectrum, the m/z axis and peak heights, calculating relative atomic mass as a weighted mean of the isotopic abundances, working backwards from a known mass to find abundances, and why the abundances must total one hundred per cent.Open →
- Empirical and molecular formulaeTerm empirical formula and term molecular formula.Open →
- The mole, the Avogadro constant and molar massValue and unit of the Avogadro constant, molar mass and state its unit and molar mass of carbon dioxide.Open →
- Moles, grams and numbers of particlesRecall questions on converting between mass, moles and number of particles using molar mass and the Avogadro constant, worked conversions in both directions, counting the atoms or ions within a formula unit, and checking an answer by working it back to the mass.Open →
- Concentration and solubilityConcentration expressed in mol dm⁻³, equation linking amount of substance, concentration and volume and standard solution.Open →
- Molar volume and gas volume correctionsAvogadro's law and molar volume of a gas.Open →
- The ideal gas equationIdeal gas equation and say what each symbol represents and assumptions made about the molecules of an ideal gas.Open →
- Stoichiometry and reacting quantitiesStoichiometry of a reaction, steps of a reacting-mass calculation and term limiting reagent.Open →
- Acid-base titration calculationsTitration designed to find, equivalence point and the end point of a titration and standardising a solution.Open →
- Atom economy, percentage yield and percentage errorAtom economy and percentage yield.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What is a standard solution, and how is one prepared?
Key term
Why is the molar volume the same for every gas?
Key term
State the ideal gas equation and say what each symbol represents.
Process
List the steps of a reacting-mass calculation.
Numbers
25.0 cm³ of sodium hydroxide solution requires 22.5 cm³ of 0.100 mol dm⁻³ hydrochloric acid. Calculate the concentration of the alkali.
Key term
Why does industry value a high atom economy?
Numbers
Heating 5.00 g of calcium carbonate gives 2.35 g of calcium oxide. Calculate the percentage yield.
Key term
Define relative atomic mass.
Process
Name the four main stages an ion passes through in a mass spectrometer.
Key term
What quantities are plotted on the two axes of a mass spectrum?
Key term
State the value and unit of the Avogadro constant.
Key term
State the equation linking mass, amount of substance and molar mass.
Key term
Why do relative masses have no units?
Key term
Why must the inside of a mass spectrometer be held at very low pressure?
Key term
Describe how relative atomic mass is calculated from mass spectrum data.
Key term
Define the term empirical formula.
Key term
Why must the particle be named whenever an amount in moles is quoted?
Numbers
Calculate the amount of substance in 8.8 g of carbon dioxide.
Key term
Define concentration expressed in mol dm⁻³.
Key term
State Avogadro's law.
Key term
In which units must each quantity be expressed when using the ideal gas equation?
Key term
What is meant by the stoichiometry of a reaction?
Key term
Distinguish between the equivalence point and the end point of a titration.
Key term
Why is the relative atomic mass of chlorine 35.5 rather than a whole number?
Key term
Describe how a sample is ionised by electron impact.
Numbers
Chlorine consists of 75.0% ³⁵Cl and 25.0% ³⁷Cl. Calculate its relative atomic mass.
Key term
Define the term molecular formula.
Key term
State the molar mass of carbon dioxide.
Numbers
Calculate the mass of 0.250 mol of sodium hydroxide.
Key term
State the equation linking amount of substance, concentration and volume.
Key term
What is meant by the molar volume of a gas?
Key term
Convert a volume of 1 dm³ into cubic metres.
Key term
What mass of calcium oxide is formed when 25.0 g of calcium carbonate is fully decomposed?
Key term
What is a titre, and what makes a set of titres concordant?
Key term
Define atom economy.
Take Chemical Calculations further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
Define relative atomic mass.
Model answer
Relative atomic mass is the weighted mean mass of the atoms of an element, taking account of the abundance of each isotope, compared with one twelfth of the mass of an atom of carbon-12.
- 2
Define relative isotopic mass.
Model answer
Relative isotopic mass is the mass of one atom of a particular isotope compared with one twelfth of the mass of an atom of carbon-12.
- 3
Why do relative masses have no units?
Model answer
Each is a ratio of one mass to another mass, so the units cancel and only a number is left.
- 4
Define relative molecular mass.
Model answer
Relative molecular mass is the sum of the relative atomic masses of all the atoms shown in the molecular formula of a substance.
- 5
What is relative formula mass, and when is it used in preference to relative molecular mass?
Model answer
Relative formula mass is the sum of the relative atomic masses in one formula unit, and it is used for ionic and giant structures such as sodium chloride, where no discrete molecule exists.
- 6
Why is the relative atomic mass of chlorine 35.5 rather than a whole number?
Model answer
Naturally occurring chlorine is a mixture of ³⁵Cl and ³⁷Cl in roughly a three to one ratio, and 35.5 is the weighted mean of the two.
What is inside Levo
Six ways to work the same material.
Chemical Calculations revision questions
- What does Chemical Calculations cover in Eduqas A-Level Chemistry?
- 12 subtopics: relative atomic, isotopic, formula and molecular mass, principles of the mass spectrometer, mass spectra, isotopic abundance and relative atomic mass, empirical and molecular formulae, the mole, the avogadro constant and molar mass, moles, grams and numbers of particles, concentration and solubility, molar volume and gas volume corrections, the ideal gas equation, stoichiometry and reacting quantities, acid-base titration calculations and atom economy, percentage yield and percentage error. Each one has its own page with questions and model answers.
- How is Chemical Calculations organised?
- By the Eduqas A410QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Chemical Calculations, 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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