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AQA GCSE Chemistry 8462
Atomic Structure and the Periodic Table
Topic overviewAtoms, elements and compoundsWord equations, symbols and balanced equationsMixturesFrom the plum pudding model to the nuclear modelBohr, Chadwick and the modern model of the atomRelative electrical charges of subatomic particlesSize and mass of atomsRelative atomic mass and electronic structureThe periodic tableDevelopment of the periodic tableMetals and non-metalsGroup 0Group 1Group 7Transition metals, and how they differ from Group 1
Bonding, Structure, and the Properties of Matter
Topic overviewChemical bonds, including metallic bondingIonic bondingIonic compoundsCovalent bonding and how it is representedThe three states of matter and changes of statePredicting state, state symbols, and the limits of the particle modelProperties of ionic compoundsProperties of small moleculesPolymers and giant covalent structuresProperties of metals and alloys, and why metals conductDiamond and graphiteGraphene and fullerenesSizes of particles and their propertiesUses of nanoparticles
Chemical Analysis
Chemical Changes
Topic overviewThe reactivity seriesMetal oxides, extraction, and redox in terms of electronsAcids reacting with metals, neutralisation and saltsSoluble saltsThe pH scale and neutralisationTitrationsStrong and weak acidsThe process of electrolysis, and molten ionic compoundsUsing electrolysis to extract metalsElectrolysis of aqueous solutionsRepresentation of reactions at electrodes as half equations
Chemistry of the Atmosphere
Topic overviewThe Earth's early atmosphereHow oxygen increased and carbon dioxide decreasedThe gases in today's atmosphere, and which are greenhouse gasesHuman activities which contribute to an increase in greenhouse gases in the atmosphereGlobal climate change and carbon footprintsAtmospheric pollutants from fuels, and their effects
Energy Changes
Organic Chemistry
Topic overviewCrude oil, hydrocarbons and alkanesFractional distillation and petrochemicalsProperties of hydrocarbonsCracking, and testing alkenes with bromine waterWhy cracking is useful, and equations for itStructure and formulae of alkenesReactions of alkenesAlcoholsCarboxylic acidsAddition polymerisationCondensation polymerisationAmino acids, DNA and naturally occurring polymers
Quantitative Chemistry
Topic overviewConservation of mass and balanced chemical equationsRelative formula mass and concentration of solutionsMass changes when a gas is involved, and measurement uncertaintyMolesAmounts of substances in equations, and balancing using molesLimiting reactantsPercentage yieldAtom economyUsing concentrations of solutions in mol/dmUse of amount of substance in relation to volumes of gases
The Rate and Extent of Chemical Change
Topic overviewMeasuring the mean rate of a reactionRate from graphs, and the gradient of a tangentFactors which affect the rates of chemical reactionsCollision theory and activation energyCatalystsReversible reactions and dynamic equilibriumThe effect of changing conditions on equilibriumThe effect of changing concentrationThe effect of temperature changes on equilibriumThe effect of pressure changes on equilibrium
Using Resources
Topic overviewUsing the Earth's resources and sustainable developmentProducing potable water in the UKDesalination, and analysing water samplesWaste water treatmentAlternative methods of extracting metalsLife cycle assessmentWays of reducing the use of resourcesCorrosion and its preventionAlloys as useful materialsGlass, clay ceramics and polymersComposites, and comparing materialsThe Haber processProduction and uses of NPK fertilisers
Chemical Analysis
- 8 subtopics
- 24 things to know
- Paper 2
What Chemical Analysis covers
Chemical Analysis is examined in Chemistry Paper 2. It covers pure substances, formulations, chromatography, tests for hydrogen, oxygen, carbon dioxide and chlorine, flame tests, metal hydroxides, tests for carbonates, halides and sulfates and flame emission spectroscopy.
Where it is assessed
Paper 2
Chemistry Paper 2: 1 hour 45 minutes, 100 marks, 50% of the GCSE.
Check the AQA specification ↗The 8 subtopics
Each one has its own page.
- Pure substancesThe chemical meaning of a pure substance, why pure substances melt and boil at fixed temperatures while mixtures change state over a range, using melting and boiling points to test purity, and the everyday meaning of pure compared with the chemist's.Open →
- FormulationsWhat a formulation is and why its components are measured in controlled quantities, the purpose of each ingredient, examples such as paints, medicines, cleaning agents, fertilisers, fuels, alloys and food sauces, and telling a formulation from a single compound or a natural mixture.Open →
- ChromatographyThe stationary and mobile phases, what decides how far a substance travels, how Rf values are defined and calculated, reading purity from a chromatogram, and why the start line is pencil and the solvent starts below it.Open →
- Tests for hydrogen, oxygen, carbon dioxide and chlorineThe burning splint test for hydrogen, the glowing splint test for oxygen, limewater turning milky for carbon dioxide, damp litmus paper bleached white by chlorine, why each test is carried out as it is, and identifying a gas from the result.Open →
- Flame testsWhich metal ions a flame test identifies, how it is carried out, the crimson, yellow, lilac, orange-red and green flames of lithium, sodium, potassium, calcium and copper, and why one colour can mask another.Open →
- Metal hydroxidesPrecipitating metal hydroxides with sodium hydroxide solution, the white precipitates of aluminium, calcium and magnesium and how excess tells them apart, the coloured precipitates of copper(II), iron(II) and iron(III), and their equations.Open →
- Tests for carbonates, halides and sulfatesTesting for carbonates with dilute acid and limewater, for halide ions with silver nitrate and dilute nitric acid giving white, cream and yellow precipitates, and for sulfate ions with barium chloride, ionic equations for the precipitates, identifying a compound from two sets of tests, and the advantages of instrumental methods.Open →
- Flame emission spectroscopyFlame emission spectroscopy as an instrumental method for metal ions in solution, why it is chosen over a flame test, how the spectroscope produces a line spectrum, and using reference spectra to identify metal ions and compare their concentrations.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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Describe the solution used to test for carbon dioxide, how the test is carried out, and how a positive and a negative result are read.
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Describe the test for halide ions and the precipitate colours given by chloride, bromide and iodide.
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Describe the test for chlorine gas, the result seen, and why the litmus paper is moistened first.
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In chemical terms, what is meant by a pure substance?
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What is a formulation?
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What are the two phases involved in any form of chromatography?
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Which reagent is added to a solution in order to identify metal ions by precipitation?
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What kind of substance is analysed by flame emission spectroscopy?
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What is the difference between the way a pure compound changes state and the way a mixture does?
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What is true of every individual chemical in a formulation?
Evaluation
What decides how far a substance travels during chromatography?
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What type of particle can a flame test identify?
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Why does adding sodium hydroxide solution to a solution of a metal salt often produce a solid?
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Describe how you would show that an unknown solid is a carbonate.
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Describe how a solution is analysed by flame emission spectroscopy.
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State the measurement you would take to check whether a solid sample is pure.
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Name three household products that are formulations.
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How is the Rf value of a compound defined?
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Describe the test for hydrogen gas and the result you would see.
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Name the five metals whose compounds you should be able to recognise from their flame colours.
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Name the three metal ions that give a white precipitate with sodium hydroxide solution.
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Which solution is used to test for halide ions, and what must be added along with it?
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What is the output produced by a flame emission spectrometer called?
Take Chemical Analysis further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Stationary phase vs Mobile phase
Stationary phase: the part of a chromatography set-up that stays still, such as the paper. Mobile phase: the solvent that moves through and carries the substances along.
Pure substance vs Formulation
Pure substance: a single element or compound with nothing else mixed in. Formulation: a mixture designed with measured components to make a useful product.
Flame test vs Flame emission spectroscopy
Flame test: identifying a metal ion from the colour a compound gives a Bunsen burner. Flame emission spectroscopy: an instrumental method giving a line spectrum that shows metal ions and their concentrations.
Questions from this topic
Each one with the model answer underneath.
- 1
In chemical terms, what is meant by a pure substance?
Model answer
A pure substance is a single element or a single compound with nothing else mixed into it.
- 2
A sample contains molecules of one compound and nothing else. Is it pure in the chemical sense?
Model answer
Yes, because it is a single compound that is not mixed with any other substance.
- 3
Why is filtered sea water not a pure substance to a chemist?
Model answer
It is still a mixture of water and dissolved salts, so it is not a single element or compound.
- 4
What is the difference between the way a pure compound changes state and the way a mixture does?
Model answer
A pure compound melts and boils at specific fixed temperatures, while a mixture melts and boils over a range of temperatures.
- 5
State the measurement you would take to check whether a solid sample is pure.
Model answer
Measure its melting point and compare it with the accepted melting point of the pure substance.
- 6
Explain why a pure element melts at one sharp temperature.
Model answer
All of its particles are identical, so they all need the same amount of energy to break free at the same temperature.
What is inside Levo
Six ways to work the same material.
Chemical Analysis revision questions
- What does Chemical Analysis cover in AQA GCSE Chemistry?
- 8 subtopics: pure substances, formulations, chromatography, tests for hydrogen, oxygen, carbon dioxide and chlorine, flame tests, metal hydroxides, tests for carbonates, halides and sulfates and flame emission spectroscopy. Each one has its own page with questions and model answers.
- How is Chemical Analysis organised?
- By the AQA 8462 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Chemical Analysis, on a schedule.
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