ccea gcse specification in - chemistry

GCSE

For first teaching from September 2017For first assessment in Summer 2018For first award in Summer 2019Subject Code: 1110

CCEA GCSE Specification in

Chemistry

Contents 1 Introduction 3 1.1 Aims 41.2 Keyfeatures 41.3 Priorattainment 51.4 Classificationcodesandsubjectcombinations

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2 Specification at a Glance

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3 Subject Content 8 3.1 Unit1:Structures,Trends,ChemicalReactions,Quantitative

ChemistryandAnalysis8

3.2 Unit2:FurtherChemicalReactions,RatesandEquilibrium,CalculationsandOrganicChemistry

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3.3 Unit3:PracticalSkills

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4 Scheme of Assessment 42 4.1 Assessmentopportunities 424.2 Assessmentobjectives 424.3 Assessmentobjectiveweightings 424.4 Qualityofwrittencommunication 434.5 Reportingandgrading

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5 Grade Descriptions

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6 Guidance on Practical Skills Assessment 47 6.1 Overview 476.2 SkillsassessedbyUnit3 476.3 TasktakinginBookletA 486.4

Taskmarking 49

7 Curriculum Objectives 50 7.1 Cross-CurricularSkillsatKeyStage4 507.2 ThinkingSkillsandPersonalCapabilitiesatKeyStage4

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8 Links and Support 54 8.1 Support 548.2 Examinationentries 548.3 Equalityandinclusion 548.4 Contactdetails

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Appendix 1 MathematicalContent

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Appendix 2 HowScienceWorks

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Appendix 3 DataLeaflet includingthePeriodicTableoftheElements

SubjectCodeQAN

1110603/1146/0

ACCEAPublication©2017

Thisspecificationisavailableonlineatwww.ccea.org.uk

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CCEAGCSEChemistryfromSeptember2017

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1 Introduction ThisspecificationsetsoutthecontentandassessmentdetailsforourGCSEcourseinChemistry.Wehavedesignedthisspecificationtomeettherequirementsof:

• NorthernIrelandGCSEDesignPrinciples;and• NorthernIrelandGCEandGCSEQualificationsCriteria.FirstteachingisfromSeptember2017.WewillmakethefirstawardbasedonthisspecificationinSummer2019.Thisspecificationisaunitisedcourse.Theguidedlearninghours,asforallourGCSEs,are120hours.ThespecificationsupportstheaimoftheNorthernIrelandCurriculumtoempoweryoungpeopletoachievetheirpotentialandtomakeinformedandresponsibledecisionsthroughouttheirlives,aswellasitsobjectives:

• todeveloptheyoungpersonasanindividual;• todeveloptheyoungpersonasacontributortosociety;and• todeveloptheyoungpersonasacontributortotheeconomyandenvironment.Ifthereareanymajorchangestothisspecification,wewillnotifycentresinwriting.Theonlineversionofthespecificationwillalwaysbethemostuptodate;toviewanddownloadthispleasegotowww.ccea.org.uk


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1.1 Aims Thisspecificationaimstoencouragestudentsto:

• developtheirknowledgeandunderstandingofthematerialworld;• developtheirunderstandingoftheeffectsofchemistryonsociety;• developtheirunderstandingoftheimportanceofscaleinchemistry;• developandapplytheirknowledgeandunderstandingofthenatureofscienceandofthescientificprocess;

• developtheirunderstandingoftherelationshipsbetweenhypotheses,evidence,theoriesandexplanations;

• developtheirawarenessofriskandtheabilitytoassesspotentialriskandpotentialbenefits;

• developandapplytheirobservational,practical,modelling,enquiryandproblem-solvingskillsandunderstandinginlaboratory,fieldandotherlearningenvironments;

• developtheirabilitytoevaluateclaimsbasedonchemistrythroughcriticalanalysisofthemethodology,evidenceandconclusionsbothqualitativelyandquantitatively;and

• developtheirskillsincommunication,mathematicsandtheuseoftechnologyinscientificcontexts.

1.2 Key features Thefollowingareimportantfeaturesofthisspecification.

• ItoffersopportunitiestobuildontheskillsandcapabilitiesdevelopedthroughthedeliveryoftheNorthernIrelandCurriculumatKeyStage3.

• Thecoursecomprisestwotheoryunits(Units1and2),whicharedesignedtobetaughtinthefirstandsecondyearsofthecourserespectively,andapracticalskillsassessmentunit(Unit3),whichismadeupofBookletAandBookletB.

• Studentscarryoutavarietyofprescribedpracticalactivities,whichappearinitalicsthroughoutthespecification.TwooftheseareassessedinUnit3:PracticalSkillsBookletA,whichstudentscarryoutinclasstowardstheendofthecourse.

• Atimetabledexamination,BookletB,completesthepracticalskillsassessment.Thisconsistsofaseriesofquestionsabouttheprescribedpracticalsandotherpracticalactivitiesthroughoutthespecification.

• Allunitsareexternallymarked.• Thespecificationallowsstudentstodeveloptransferableskillsthatwillbenefittheminvocationaltrainingandemployment.ItalsoenablesthemtoprogresstothestudyofscienceandrelatedcoursesatGCEAdvancedlevelandAdvancedSubsidiarylevel.

• DetailsofthemathematicalskillsexpectedofstudentsaregiveninAppendix1.• ThecontentinthisspecificationisassessedinthecontextofHowScienceWorks(seeAppendix2).

• Thereisarangeofsupportavailableforbothteachersandstudents,includingspecimenpapers,markschemesandplanningframeworks.YoucandownloadthesefromourChemistrymicrositeatwww.ccea.org.uk


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1.3 Prior attainment Studentsdonotneedtohavereachedaparticularlevelofattainmentbeforebeginningtostudythisspecification.However,thespecificationbuildsontheknowledge,skillsandunderstandingdevelopedthroughtheNorthernIrelandCurriculumforscienceatKeyStage3.Beforestudyingthisspecification,weexpectstudentstohavealevelofskillsinscience,numeracy,literacyandcommunicationthatiscommensuratewithhavingstudiedsciencetoKeyStage3.1.4 Classification codes and subject combinations Everyspecificationhasanationalclassificationcodethatindicatesitssubjectarea.Theclassificationcodeforthisqualificationis1110.Pleasenotethatifastudenttakestwoqualificationswiththesameclassificationcode,schools,collegesanduniversitiesthattheyapplytomaytaketheviewthattheyhaveachievedonlyoneofthetwoGCSEs.ThesamemayoccurwithanytwoGCSEqualificationsthathaveasignificantoverlapincontent,eveniftheclassificationcodesaredifferent.Becauseofthis,studentswhohaveanydoubtsabouttheirsubjectcombinationsshouldcheckwiththeschools,collegesanduniversitiesthattheywouldliketoattendbeforebeginningtheirstudies.


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2 Specification at a Glance ThetablebelowsummarisesthestructureofthisGCSEcourse.

Content

Assessment

Weightings

Availability

Unit1:Structures,Trends,ChemicalReactions,QuantitativeChemistryandAnalysis

ExternalwrittenexaminationStudentsanswercompulsorystructuredquestionsthatrequireshortresponses,extendedwritingandcalculations.Therearetwotiersofentry.FoundationTier:1hour

HigherTier:1hour15mins

35%

Summerfrom2018

Unit2:FurtherChemicalReactions,RatesandEquilibrium,CalculationsandOrganicChemistry

ExternalwrittenexaminationStudentsanswercompulsorystructuredquestionsthatrequireshortresponses,extendedwritingandcalculations.Therearetwotiersofentry.FoundationTier:1hour15minsHigherTier:1hour30mins

40%

Summerfrom2019


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Content

Assessment

Weightings

Availability

Unit3:PracticalSkills

BookletAExternallymarkedStudentscarryouttwopre-releasepracticaltasksinthefinalyearofstudy.Therearetwotiersofentry.FoundationandHigherTiers:2hours

7.5%

Between1Januaryand1Mayfrom2019

Booklet B Externalwrittenexamination Studentsanswercompulsorystructuredquestionsthatrequireshortresponses,extendedwritingandcalculations,allsetinapracticalcontext.Therearetwotiersofentry.FoundationandHigherTiers:1hour

17.5%

(Unit3total:25%)

Summerfrom2019

Studentsmusttakeatleast40percentoftheassessment(basedonunitweightings)attheendofthecourseasterminalassessment.


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3 Subject Content Wehavedividedthiscourseintothreeunits.Thecontentofeachunitandtherespectivelearningoutcomesappearbelow.ContentfortheHigherTieronlyisinbold.QuestionsinHigherTierpapersmaybesetonanycontentinthespecification.ContentfortheFoundationTierisinnormaltype.QuestionsinFoundationTierpaperswillonlybesetonthiscontent.Thenineprescribedpracticals,whichareassessedinBookletsAandBofUnit3:PracticalSkills,areshowninitalics.3.1 Unit 1: Structures, Trends, Chemical Reactions,

Quantitative Chemistry and Analysis Thisunitintroducesandexploressafepracticalandtheoreticalchemistryintermsofatomicstructure,structureandbondingintraditional,newandnanoparticles,patternsinthePeriodicTable,reactionsofacidsincludingpreparationofpure,drysalts,solubilityandchemicalanalysis.Studentsareexpectedtoexpressthemselvesaccuratelyintermsofformulae,ionicequationsandbalancedsymbolequations.Thesectiononquantitativechemistryincludescalculationsintermsofamountsinmolesandpercentageyield.

Content LearningOutcomes

1.1Atomicstructure

Studentsshouldbeableto:

1.1.1 demonstrateknowledgeandunderstandingofhowideasabouttheatomchangedovertime,withreferenceto:• thePlumPuddingmodel;• Rutherford’smodelofanucleussurroundedbyelectrons;and

• thediscoveryoftheneutronbyChadwick,leadingtotoday’smodelofanatom;

1.1.2 describethestructureofanatomasacentralpositivelychargednucleuscontainingprotonsandneutrons(mostofthemass)surroundedbyorbitingelectronsinshells;

1.1.3 statetherelativechargesandapproximaterelativemassesofprotons,neutronsandelectrons;and

1.1.4 defineatomicnumberasthenumberofprotonsinanatom.


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1.1Atomicstructure(cont.)


1.1.5 definemassnumberasthetotalnumberofprotons andneutronsinanatom;1.1.6 demonstrateknowledgeandunderstandingthatan

atomasawholehasnoelectricalchargebecausethenumberofprotonsisequaltothenumberofelectrons;

1.1.7 calculatethenumberofprotons,neutronsand

electronsinanatomoranionanddeducethechargeonanionordeterminethenumberofsubatomicparticlesgiventhecharge;

1.1.8 writeanddrawtheelectronicconfiguration(structure)

ofatomsandionswithatomicnumber1–20;

1.1.9 recallthatatomshavearadiusofabout0.1nm(1×10-10m)andthatthenucleusislessthan1/10000ofthatoftheatom(lessthan1×10-14m);

1.1.10 defineisotopesasatomsofanelementwiththesame

atomicnumberbutadifferentmassnumber,indicatingadifferentnumberofneutrons;

1.1.11 interpretdataonthenumberofprotons,neutronsand

electronstoidentifyisotopesofanelement;1.1.12 calculatetherelativeatomicmassofelementsfromthe

massnumberandabundancesofitsisotopes;

1.1.13 recallthatacompoundistwoormoreelementschemicallycombined;

1.2BondingIonicbonding

1.2.1 demonstrateknowledgeandunderstandingthatanionisachargedparticleformedwhenanatomgainsorloseselectronsandamolecularionisachargedparticlecontainingmorethanoneatom;and

1.2.2 definethetermscationandanionandexplain,using

dotandcrossdiagrams,howionsareformedandhowionicbondingtakesplaceinsimpleioniccompounds,limitedtoelementsinGroups1(I)and2(II)withelementsinGroups6(VI)and7(VII),theionsofwhichhaveanoblegaselectronicconfiguration.


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Ionicbonding(cont.)


1.2.3 demonstrateknowledgeandunderstandingthat:• ionicbondinginvolvesattractionbetweenoppositelychargedions;

• ionicbondsarestrong;and• substantialenergyisrequiredtobreakionicbonds;

1.2.4 recognisethationicbondingistypicalofmetalcompounds;

Covalentbonding

1.2.5 describeasinglecovalentbondasasharedpairof electrons; 1.2.6 explain,usingdotandcrossdiagrams,howcovalent

bondingoccursinH2, Cl2,HCl, H2O,NH3,CH4andsimilarmoleculesandlabellonepairsofelectrons;

1.2.7 drawdotandcrossdiagramsandindicatethepresence

ofmultiplebondsinO2,N2andCO2; 1.2.8 recognisecovalentbondingastypicalofnon-metallic

elementsandcompounds;

1.2.9 demonstrateknowledgeandunderstandingthatamoleculeistwoormoreatomscovalentlybondedandthatdiatomicmeansthattherearetwoatomscovalentlybondedinamolecule;

1.2.10 demonstrateknowledgeandunderstandingthat

covalentbondsarestrongandthatsubstantialenergyisrequiredtobreakcovalentbonds;


acovalentbondmayberepresentedbyaline;and

Metallicbonding

1.2.12 demonstrateknowledgeandunderstandingthatmetallicbondingresultsfromtheattractionbetweenthepositiveionsinaregularlatticeandthedelocalisedelectrons.


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1.3StructuresIonicstructures


1.3.1 usetheacceptedstructuralmodelforgiantioniclatticestoexplainthephysicalpropertiesofionicsubstancessuchassodiumchloride,includingmelting

point,boilingpointandelectricalconductivity(drawing adiagramofagiantioniclatticeisnotexpectedbut studentsshouldbeabletorecogniseit);

1.3.2 recallthatmostioniccompoundsaresolubleinwater;

Molecularcovalentstructures

1.3.3 usetheacceptedstructuralmodelformolecularcovalentstructurestoexplainthephysicalpropertiesofmolecularcovalentstructuressuchasiodineandcarbondioxide,includingmeltingpoint,boilingpointandelectricalconductivity;

1.3.4 demonstrateknowledgeandunderstandingthatthe

intermolecularforcesbetweencovalentmoleculesareweakforcescalledvanderWaals’forces;

1.3.5 recallthatmanycovalentmolecularsubstancesare

insolubleinwater;

Giantcovalentstructures

1.3.6 demonstrateknowledgeandunderstandingofthegiantcovalentstructureofcarbon(diamond)andcarbon(graphite),andpredictandexplaintheirphysicalproperties,including:• electricalconductivity;• hardness;• meltingpointandboilingpoint;and• theirusesincuttingtools(diamond),lubricantsandpencils(graphite);and

Metallicstructures

1.3.7 usetheacceptedstructuralmodelformetalstopredictandexplaintheirstructureandphysicalpropertiesincludingmeltingpoint,malleability,ductilityandelectricalconductivity.


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Metallicstructures(cont.)


1.3.8 demonstrateknowledgeandunderstandingthatanalloyisamixtureoftwoormoreelements,atleastoneofwhichisametal,andtheresultingmixturehasmetallicproperties;

1.3.9 demonstrateknowledgeandunderstandingthatthe

differentsizesofatomsinanalloydistortthelayersinthemetallicstructure,makingitmoredifficultforthemtoslideovereachother,andsoalloysareharderthanpuremetals;

1.3.10 recallthatgoldusedinjewelleryisusuallyanalloywithsilver,copperandzinc,thattheproportionofgoldismeasuredincarats,andthat24caratgoldindicatespuregoldand18caratgoldindicates75%gold;

Structureandbondingofcarbon

1.3.11 demonstrateknowledgeandunderstandingthatcarboncanformfourcovalentbonds;

1.3.12 demonstrateknowledgeandunderstandingofthestructureofgraphene(asingleatomthicklayerofgraphite),explainitsphysicalproperties,includingstrengthandelectricalconductivity,andrecallitsusessuchasthoseinbatteriesandsolarcells;

1.3.13 demonstrateknowledgeandunderstandingofthemeaningofthetermallotropeasappliedtocarbon(diamond),carbon(graphite)andgraphene;and

Classificationofstructures

1.3.14 usegiveninformationtoclassifythestructureofsubstancesasgiantioniclattice,molecularcovalent,giantcovalentormetallic.


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1.4Nanoparticles


1.4.1 demonstrateknowledgeandunderstandingthatnanoparticlesarestructuresthatare1–100nminsizeandcontainafewhundredatoms;

1.4.2 demonstrateknowledgeandunderstandingofsurface

areatovolumerelationshipsandthat,asthesideofacubedecreasesbyafactorof10,thesurfaceareatovolumeratioincreasesbyafactorof10;


nanoparticleshavepropertiesdifferentfromthoseforthesamematerialinbulk,duetotheirhighsurfaceareatovolumeratio;

1.4.4 evaluatethebenefitsofnanoparticlesinsuncreams,

includingbetterskincoverageandmoreeffectiveprotectionfromtheSun’sultravioletrays,andtherisks,suchaspotentialcelldamageinthebodyandharmfuleffectsontheenvironment;

1.5Symbols,formulaeandequations

1.5.1 recognisesymbolsandnamesforcommonelementsandrecallthediatomicelements;

1.5.2 interpretchemicalformulaebynamingtheelements

andstatingthenumberofeachtypeofatompresent;1.5.3 writechemicalformulaeofcompounds;1.5.4 demonstrateunderstandingthatchemicalreactionsuse

upreactantsandproducenewsubstancescalledproducts;

1.5.5 constructwordequationstodescribetherangeof

reactionscoveredinthisspecification;and1.5.6 recognisethatinachemicalreactionnoatomsarelost

ormadebuttheyarerearranged,andasaresultwecanwritebalancedsymbolequationsshowingtheatomsinvolved.


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1.5Symbols,formulaeandequations(cont.)


1.5.7 writebalancedsymbolequationsforallreactionscoveredinthisspecificationandforunfamiliarchemicalreactionswhenthenamesofthereactantsandproductsarespecified;

1.5.8 writebalancedionicequationsforreactionscovered

inthisspecification;1.5.9 writehalfequationsforreactionscoveredinthis

specification;1.5.10 demonstrateknowledgeandunderstandingthatin

chemicalequationsthethreestatesofmatterareshownas(s),(l)and(g),with(aq)foraqueoussolutions,andincludeappropriatestatesymbolsinequationsforthereactionsinthisspecification;

1.6ThePeriodicTableBasicstructureofthePeriodicTable

1.6.1 describehowMendeleevarrangedtheelementsinthePeriodicTableandleftgapsforelementsthathadnotbeendiscoveredatthattime,andhowthisenabledhimtopredictpropertiesofundiscoveredelements;

1.6.2 demonstrateknowledgeandunderstandingofhowscientificideashavechangedovertimeintermsofthedifferencesandsimilaritiesbetweenMendeleev’sPeriodicTableandthemodernPeriodicTable;

1.6.3 describeanelementasasubstancethatconsistsof

onlyonetypeofatomanddemonstrateunderstandingthatelementscannotbebrokendownintosimplersubstancesbychemicalmeans;

1.6.4 demonstrateknowledgeandunderstandingthatagroupisaverticalcolumninthePeriodicTableandaperiodisahorizontalrow;and

1.6.5 identifyandrecallthepositionofmetalsandnon-metalsinthePeriodicTableanddistinguishbetweenthemaccordingtotheirproperties,includingconductionofheatandelectricity,ductility,malleability,meltingpointandsonority.


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BasicstructureofthePeriodicTable(cont.)


1.6.6 identifyelementsassolids,liquidsandgases(atroomtemperatureandpressure)inthePeriodicTable;


elementsinthesamegroupinthePeriodicTablehavethesamenumberofelectronsintheiroutershellandthisgivesthemsimilarchemicalproperties;

1.6.8 recallthatelementswithsimilarpropertiesappearinthesamegroup(forexampleGroup1(I)andGroup2(II)aregroupsofreactivemetals,Group7(VII)isagroupofreactivenon-metalsandGroup0isagroupofnon-reactivenon-metals),locatethesegroupsinthePeriodicTableandrecallthenamesofthegroups;

Group1(I)

1.6.9 demonstrateknowledgeandunderstandingthatthealkalimetalshavelowdensityandthefirstthreearelessdensethanwater;

1.6.10 assessandmanagerisksassociatedwiththestorageanduseofalkalimetalsandrecallthatalkalimetalsareeasilycut,areshinywhenfreshlycutandtarnishrapidlyinair;


Group1(I)metalsreactwithwatertoproducehydrogenandametalhydroxide,andgiveobservationsforthereactions;

1.6.12 demonstrateknowledgeandunderstandingthatalkali

metalshavesimilarchemicalpropertiesbecausewhentheyreactanatomlosesanelectrontoformapositiveionwithastableelectronicconfiguration;

1.6.13 writehalfequationsfortheformationofaGroup1(I)ionfromitsatom;and

1.6.14 demonstrateknowledgeandunderstandingofhowthetrendinreactivitydownthegroupdependsontheoutershellelectronsoftheatoms.


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Group1(I)(cont.)


1.6.15 demonstrateknowledgeandunderstandingthatmostGroup1(I)compoundsarewhiteanddissolveinwatertogivecolourlesssolutions;

Group7(VII) 1.6.16 recalldataaboutthecolour,physicalstateatroomtemperatureandpressure,diatomicityandtoxicityoftheelementsinGroup7(VII),interpretgivendatatoestablishtrendswithinthegroupandmakepredictionsbasedonthesetrends;

1.6.17 recalltheobservationswhensolidiodinesublimesonheatinganddemonstrateunderstandingofthetermsublimation;

1.6.18 describehowtotestforchlorinegas(dampuniversalindicatorpaperchangestoredandthenbleacheswhite);

1.6.19 investigatethedisplacementreactionsofGroup7(VII)

elementswithsolutionsofotherhalidestoestablishthetrendinreactivitywithinthegroupandmakepredictionsbasedonthistrend;

1.6.20 demonstrateknowledgeandunderstandingofhowthe

reactivitydownthegroupdependsontheoutershellelectronsoftheatoms;

1.6.21 demonstrateknowledgeandunderstanding thatthehalogenshavesimilarchemicalpropertiesbecausewhentheyreactanatomgainsanelectrontoformanegativeionwithastableelectronicconfiguration;

1.6.22 writehalfequationsfortheformationofahalideionfromahalogenmoleculeoratom;

Group0

1.6.23 usetheconceptofelectronicconfigurationtoexplainthelackofreactivityandthestabilityofthenoblegases;and

1.6.24 recallthatthenoblegasesarecolourlessgases.


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Group0(cont.)


1.6.25 demonstrateknowledgeandunderstandingofthetrendinboilingpointsofthenoblegasesgoingdownthegroup;

Transitionmetals

1.6.26 comparethephysicalpropertiesofthetransitionmetalswithGroup1(I)elements,includingmeltingpointanddensity,anddemonstrateunderstandingthatthetransitionmetalsaremuchlessreactivewithwater;

1.6.27 demonstrateknowledgethattransitionelementsformionswithdifferentcharges(forexampleiron(II)andiron(III))andformcolouredcompounds:• copper(II)oxideisblack;• copper(II)carbonateisgreen;• hydratedcopper(II)sulfateisblue;and• copper(II)saltsareusuallyblueinsolution;

1.7QuantitativechemistryFormulamass

1.7.1 recallthattherelativeatomicmass(Ar)ofanatomisthemassoftheatomcomparedwiththatofthecarbon-12isotope,whichhasamassofexactly12,anddemonstrateknowledgeandunderstandingthatArisaweightedmeanofthemassnumbers(linkedto1.1.12);

1.7.2 calculatetherelativeformulamass(Mr)(relativemolecularmass)ofacompoundandthepercentageofanelement,bymass,inacompound;

Themole

1.7.3 demonstrateknowledgeandunderstandingthatchemicalamountsaremeasuredinmolesandthatthemassofonemoleofasubstanceingramsisnumericallyequaltotherelativeformulamass;

1.7.4 convertthegivenmassofasubstancetotheamountofthesubstanceinmoles(andviceversa)byusingtherelativeatomicorformulamass;and

1.7.5 demonstrateknowledgeandunderstandingoftheimportanceofscaleinchemistryintermsofcalculatingmolesfrommassesgivenintonnesandkilograms,forexampleinindustrialprocesses.


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Themole(cont.)


1.7.6 calculatethereactingmassesofreactantsorproducts,givenabalancedsymbolequationandusingmolesandsimpleratio,includingexampleswherethereisalimitingreactant;

Percentageyield

1.7.7 calculatethetheoreticalyieldandthepercentageyieldofachemicalreactiongiventheactualyield;

1.7.8 recognisepossiblereasonswhythepercentageyieldofaproductislessthan100%,includinglossofproductinseparationfromthereactionmixture,asaresultofsidereactionsorbecausethereactionisreversibleandmaynotgotocompletion;

Calculationoftheformulaeofcompounds

1.7.9 demonstrateknowledgeandunderstandingofthetermsempiricalformula,molecularformula,hydrated,anhydrousandwaterofcrystallisation;

1.7.10 demonstrateknowledgeandunderstandingthatwater

ofcrystallisationcanberemovedbyheatingtoconstantmassandanythermaldecompositionmaybecarriedouttocompletionbyheatingtoconstantmass;

1.7.11 calculatetherelativeformulamassofcompounds

containingwaterofcrystallisation;1.7.12 calculatethepercentageofwaterofcrystallisationina

compound;1.7.13 determinetheempiricalformulaeofsimple

compoundsanddeterminethemolesofwaterofcrystallisationpresentinahydratedsaltfrompercentagecomposition,masscompositionorexperimentaldata;and

• determinethemassofwaterpresentinhydratedcrystals (PrescribedPracticalC1).


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1.8Acids,basesandsaltsIndicatorsandpH


1.8.1 recallthecoloursofphenolphthaleinandmethylorangeinacidic,alkalineandneutralsolutions;

1.8.2 describetheeffectsofacidic,alkalineandneutralsolutionsonindicatorpapers(redandbluelitmuspapersanduniversalindicatorpaper)andtheuseofapHmetertogivepHdatatoatleastonedecimalplace;

1.8.3 interpretgivendataaboutuniversalindicator(colourorpH)toclassifysolutionsasacidic,alkalineorneutralandtoindicatetherelativestrengthsofacidicandalkalinesolutionsaccordingtothefollowingclassification:• pH0–2strongacid;• pH3–6weakacid;• pH7neutral;• pH8–11weakalkali;and• pH12–14strongalkali;

1.8.4 demonstrateknowledgeandunderstandingthatacids

dissolveinwatertoproducehydrogen(H+(aq))ions;1.8.5 recallthatthehighertheconcentrationofhydrogen

ionsinanacidicsolution,thelowerthepH;1.8.6 demonstrateknowledgeandunderstandingthatalkalis

dissolveinwatertoproducehydroxide(OH–(aq))ions;1.8.7 demonstrateknowledgeandunderstandingthat

strongacidsandstrongalkalisarecompletelyionisedinwater,recallexamplesofstrongacids(includinghydrochloricacid,sulfuricacidandnitricacid)andrecallexamplesofstrongalkalis(includingsodiumhydroxideandpotassiumhydroxide);and

1.8.8 demonstrateknowledgeandunderstandingthatweak

acidsandweakalkalisarepartiallyionisedinwater,recallexamplesofweakacids(includingethanoicacidandcarbonicacid)andrecallexamplesofweakalkalis(includingammonia).


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IndicatorsandpH(cont.)


1.8.9 explaindiluteandconcentratedintermsoftheamountofsubstancesinsolution;

Reactionsofacids

1.8.10 describeneutralisationasthereactionbetweenthehydrogenionsinanacidandthehydroxideionsinanalkalitoproducewaterandrecalltheionicequationas:

H+(aq)+OH–(aq)→H2O(l) 1.8.11 investigatethetemperaturechangeduring neutralisationanddemonstrateunderstandingthat neutralisationreactionsareexothermic(heatisgiven out);1.8.12 recallthatabaseisametaloxideorhydroxidewhich

neutralisesanacidtoproduceasaltandwaterandthatanalkaliisasolublebase;

1.8.13 demonstrateknowledgeandunderstandingofand

writeobservationsonandequationsfor thegeneralreactionsofhydrochloric,sulfuricandnitricacidswith:• metals;• bases;• carbonates;• hydrogencarbonates;and• ammonia;

1.8.14 describehowtotestforhydrogengas:applyalighted

splintandapoppingsoundresults;1.8.15 describehowtotestforcarbondioxide:

limewater(calciumhydroxidesolution)willchangefromcolourlesstomilkyifthetestispositive;and

Preparationofsolublesalts

1.8.16 demonstrateknowledgeandunderstandingthatasaltisacompoundformedwhensomeorallofthehydrogenionsinanacidarereplacedbymetalionsorammoniumions.


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Preparationofsolublesalts(cont.)


1.8.17 demonstrateknowledgeandunderstandingthatmostGroup1(I),Group2(II),aluminiumandzincsaltsarewhiteandiftheydissolveinwatertheygivecolourlesssolutions,andthattransitionmetalsaltsaregenerallycoloured;

1.8.18 demonstrateknowledgeandunderstandingofhowpuredrysamplesofsolublesaltscanbepreparedby:• addingexcessinsolublesubstancestoacid;• addingalkalitoacid,orviceversa,inthepresenceofanindicator;and

• repeatingwithoutindicatororremovingtheindicatorusingcharcoal

(methodsofdryingtoincludeplacinginadesiccatororalowtemperatureovenordryingbetweentwosheetsoffilterpaper);

1.8.19 developawarenessoftheimportanceofsafetyinthe

laboratorytoassesspotentialrisks,includingthehazardsassociatedwithchemicalslabelledwiththeGHS/CLPinternationalchemicalhazardlabelling(includingtoxic,corrosive,flammable,explosiveandcaution);

• investigatethereactionsofacids,includingtemperature changesthatoccur(PrescribedPracticalC2);

• investigatethepreparationofsolublesalts(Prescribed PracticalC3);

1.9ChemicalanalysisAssessingpurityandseparatingmixtures

1.9.1 demonstrateknowledgeandunderstandingthatapuresubstanceisasingleelementorcompoundnotmixedwithanyothersubstance;and

1.9.2 demonstrateknowledgeandunderstandingthatpure

elementsandcompoundsmeltandboilatspecifictemperaturesandmeltingpointandboilingpointcanbeusedtodistinguishpuresubstancesfrommixtures.


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Assessingpurityandseparatingmixtures(cont.)


1.9.3 demonstrateknowledgeandunderstandingthataformulationisamixturethathasbeendesignedasausefulproductandisformedbymixingtogetherseveraldifferentsubstancesincarefullymeasuredquantitiestoensuretheproducthastherequiredproperties,forexamplealloys,medicinesandfertilisers;

1.9.4 demonstrateknowledgeandunderstandingofthe

termssoluble,insoluble,solute,solvent,solution,residue,filtrate,distillate,miscible,immiscible,evaporationandcondensation;

1.9.5 investigatepracticallyhowmixturescanbeseparated

usingfiltration,crystallisation,paperchromatography,simpledistillationorfractionaldistillation(includingusingfractionaldistillationinthelaboratorytoseparatemiscibleliquids,forexampleethanolandwater);

1.9.6 describepaperchromatographyastheseparationof

mixturesofsolublesubstancesbyrunningasolvent(mobilephase)throughthemixtureonthepaper(stationaryphase),whichcausesthesubstancestomoveatdifferentratesoverthepaper;

1.9.7 interpretapaperchromatogramincludingcalculatingRfvalues;

1.9.8 analysegivendataonmixturestomakejudgementson

themosteffectivemethodsofseparationandplanexperimentstocarryoutthisseparation;

1.9.9 describehowwatercanbemadepotable,includingtheneedforfiltration,sedimentationandchlorination;

1.9.10 describehowseawatercanbemadepotableusingdistillation;and

1.9.11 useanhydrouscopper(II)sulfatetotestforwater.


23


Testsforions


1.9.12 describehowtocarryoutaflametestusingnichromewireandconcentratedhydrochloricacidtoidentifymetalions;

1.9.13 demonstrateknowledgeoftheflamecoloursofdifferentmetalions:• lithium(crimson);• sodium(yellow/orange);• potassium(lilac);• calcium(brickred);and• copper(II)(blue–green/green–blue);

1.9.14 describethetestforCu2+,Fe2+,Fe3+,Al3+,Zn2+andMg2+

ionsinsolutionusingsodiumhydroxidesolutionandammoniasolution;

1.9.15 describethetestsforthefollowing:

• chloride,bromideandiodide(usingsilvernitratesolution);

• sulfate(usingbariumchloridesolution);and• carbonate(usingdiluteacidandidentifyingthecarbondioxideevolved);

1.9.16 writeionicequationsforthehalideandsulfateion

testsandtestsformetalionsusingsodiumhydroxidesolution;

1.9.17 demonstrateknowledgeandunderstandingthatmany

testsforanionsandcationsareprecipitationreactions;1.9.18 planexperimentstoidentifycationsandanionspresent

inanunknownoragivencompound;and• identifytheionsinanioniccompoundusingchemicaltests (PrescribedPracticalC4).


24


1.10Solubility


1.10.1 definesolubilityasthemassofsolidrequiredtosaturate100gofwaterataparticulartemperature;

1.10.2 usegivendatatocalculatesolubilityvalues;

1.10.3 experimentallydeterminethesolubilityofasolidinwater(otherpracticalactivity);

1.10.4 demonstrateknowledgeandunderstandingthatasaturatedsolutionisoneinwhichnomoresolutewilldissolveatthattemperature,demonstrateunderstandingthatwhenahotconcentratedsolutioniscooledsomeofthesolutewillbedeposited,andcalculatethemassofsolutedeposited;

1.10.5 drawandinterpretsolubilitycurves(graphofsolubilitying/100gwateragainsttemperaturein°C);and

1.10.6 demonstrateknowledgeandunderstandingthatthesolubilityofgasesdecreasesastemperatureincreases,whereasthesolubilityofasolidgenerallyincreasesastemperatureincreases.


25

3.2 Unit 2: Further Chemical Reactions, Rates and Equilibrium, Calculations and Organic Chemistry

Inthisunit,studentsextendtheirknowledgeofsafepracticalandtheoreticalchemistryfurther toincludereactivityseries,redox,ratesofreaction,energychangesinchemicalreactionsandgaschemistry.Studentsareintroducedtoorganicchemistry,equilibriuminchemicalreactionsandelectrochemistry.Theyalsocontinuetowritemorecomplexequationsandcarryoutincreasinglycomplexcalculationsofamountsinmolesinvolvingsolutionandgaschemistry.

Content

LearningOutcomes

2.1Metalsandreactivityseries


2.1.1 recallthereactivityseriesofmetals,includingK,Na,Ca,Mg,Al,Zn,FeandCu;

2.1.2 describethereactions,ifany,oftheabovemetalswith

thefollowinganddescribehowtocollectthegasproduced,whereappropriate:• air;• water;and• steam;

2.1.3 explainhowthereactivityofmetalsisrelatedtothe

tendencyofametaltoformitspositiveion;2.1.4 explainanddescribethedisplacementreactionsof

metalswithothermetalionsinsolution;2.1.5 collectand/oranalyseexperimentaldatatopredict

whereanunfamiliarelementshouldbeplacedinthereactivityseriesormakepredictionsabouthowitwillreact;

2.1.6 examinetherelationshipbetweentheextractionof

ametalfromitsoreanditspositioninthereactivityseries,forexample:• aluminium,areactivemetal,isextractedbyelectrolysis;and

• iron,alessreactivemetal,isextractedbychemicalreduction;and

2.1.7 recallthattheEarth’sresourcesofmetaloresarelimitedandthatalternativeextractionmethods,suchasphytomining,areused.


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Content

LearningOutcomes

Metalsandreactivityseries(cont.)


2.1.8 recallthefollowingaspectsofphytomining:• plantsareusedtoabsorbmetalcompoundssuchascopper(II)compounds;

• theplantsareharvested,thenburnedtoproduceash,whichcontainsthemetalcompounds;

• anacidisaddedtotheashtoproduceasolutioncontainingdissolvedmetalcompounds(leachate);

• coppercanbeobtainedfromthesesolutionsbydisplacementusingscrapiron;and

• thistechniqueavoidstraditionalminingmethodsofdigging,movinganddisposingoflargeamountsofrock;

• investigatethereactivityofmetals(PrescribedPracticalC5);

2.2Redox,rustingandiron

2.2.1 recogniseoxidationandreductionintermsoflossorgainofoxygenorhydrogenandidentifyinareactionorsymbolequationwhichspeciesisoxidisedandwhichisreduced(linktosuitableindustrialprocessescoveredinthisspecification);

2.2.2 recogniseoxidationandreductionintermsoflossor

gainofelectronsandidentifyinasymbolequation,ionicequationorhalfequationwhichspeciesisoxidisedandwhichisreduced(linktosuitableindustrialprocessescoveredinthisspecification);

2.2.3 investigateexperimentallyrustingasareactionofiron

withwaterandairproducinghydratediron(III)oxide(otherpracticalactivity);and

2.2.4 demonstrateknowledgeandunderstandingofthe

methodsusedtopreventironfromrusting,includingbarriermethodssuchaspainting,oiling,plasticcoatingandsuitablemetalcoatingorplating(galvanising),andexplainsacrificialprotectionofironrelatedtothereactivityseries.


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Content

LearningOutcomes

Redox,rustingandiron(cont.)


2.2.5 describetheextractionofironfromhaematiteincluding:• theproductionofthereducingagent;• thereductionofhaematite;and• theremovalofacidicimpurities;

2.2.6 demonstrateknowledgeandunderstandingthatironis

usedinbridgesandstructuresduetoitsstrength;

2.3Ratesofreaction

2.3.1 demonstrateknowledgeandunderstandingthattherateofareactionmaybedeterminedbymeasuringthelossofareactantorgainofaproductovertimeandusetheequation:

rate=

2.3.2 suggestappropriatepracticalmethodstomeasuretherateofareactionandcollectreliabledata(methodslimitedtomeasuringachangeinmass,gasvolumeorformationofaprecipitateagainsttime)forthereactionof:• metalswithdiluteacid;• calciumcarbonate/marblechipswithdilutehydrochloricacid;

• catalyticdecompositionofhydrogenperoxide;and• sodiumthiosulfatewithacid(equationnotrequired);

2.3.3 interpretexperimentaldataquantitatively,forexample

drawingandinterpretingappropriategraphstodeterminetherateofreaction;and

2.3.4 describeandexplaintheeffectsonratesofreaction whentherearechangesin:

• temperature;• concentration;• frequencyandenergyofcollisionsbetween particles;and• changesinparticlesizeintermsofsurfaceareatovolumeratio.

1time


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Content

LearningOutcomes

Ratesofreaction(cont.)


2.3.5 demonstrateknowledgeandunderstandingthatacatalystisasubstancewhichincreasestherateofareactionwithoutbeingusedupandrecallthattransitionmetalsandtheircompoundsareoftenusedascatalysts;

2.3.6 explaincatalyticactionintermsofprovidinganalternativereactionpathwayofloweractivationenergy;

• investigatehowchangingavariablechangestherateofreaction(PrescribedPracticalC6);

2.4Equilibrium

2.4.1 demonstrateknowledgeandunderstandingthatmanychemicalreactionsarereversibleandthedirectionofareversiblereactioncanbechangedbyalteringthereactionconditions;


dynamicequilibriumoccursinaclosedsystemwhentheratesofforwardandreversereactionsareequalandtheamountsofreactantsandproductsremainconstant;

2.4.3 stateLeChâtelier’sPrincipleanduseittopredictthe

qualitativeeffectsofchangesoftemperature,pressureandconcentrationonthepositionofequilibriumforaclosedhomogeneoussystem;

2.4.4 describetheHaberprocessasareversiblereaction

betweennitrogenandhydrogentoformammonia,anddescribeandexplaintheconditionsusedandthetrade-offbetweentherateofproductionandthepositionofequilibrium;and

2.5Organicchemistry

2.5.1 demonstrateknowledgeandunderstandingthatcarboncanformfourcovalentbondsandthereisalargenumberofcarboncompounds,thestudyofwhichissimplifiedbygroupingthecompoundsintohomologousseries.


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Content

LearningOutcomes

2.5Organicchemistry(cont.)


2.5.2 defineahomologousseriesasafamilyoforganicmoleculesthathavethesamegeneralformula,showsimilarchemicalproperties,showagradationintheirphysicalpropertiesanddifferbyaCH2group;

2.5.3 recallthatahydrocarbonisacompound/molecule

consistingofhydrogenandcarbononly;2.5.4 recallthegeneralformulaofthealkanesandthe

molecularformula,structuralformulaandstateatroomtemperatureandpressureofmethane,ethane,propaneandbutane;

2.5.5 recallthatcrudeoilisafiniteresourceandisthemainsourceofhydrocarbonsandafeedstockforthepetrochemicalindustry;

2.5.6 describeandexplaintheseparationofcrudeoilbyfractionaldistillation;

2.5.7 describethefractionsaslargelyamixtureofcompoundsofformulaCnH2n+2,whicharemembersofthealkanehomologousseries,andrecallthenamesandusesofthefollowingfractions:• refinerygasesusedforbottledgases;• petrolusedasafuelforcars;• naphthausedtomanufacturechemicalsandplastics;• keroseneasafuelforaircraft;• dieselasafuelforcarsandtrains;• fueloilsusedasfuelforships;and• bitumenusedtosurfaceroadsandroofs;

2.5.8 explainthatcrackinginvolvesthebreakdownoflarger

saturatedhydrocarbons(alkanes)intosmallermoreusefulones,someofwhichareunsaturated(alkenes);and

2.5.9 describethecompletecombustionofalkanestoproducecarbondioxideandwater,includingobservationsandteststoidentifytheproducts.


30

Content

LearningOutcomes



2.5.10 describetheincompletecombustionofalkanestoproducecarbonmonoxideandwaterandsometimescarbon(soot–equationsfortheproductionofsootarenotrequired);

2.5.11 demonstrateknowledgeandunderstandingthatcarbonmonoxideisatoxicgasthatcombineswithhaemoglobinintheblood,reducingitscapacitytocarryoxygen;

2.5.12 recallthegeneralformulaofthealkenesandthemolecularformula,structuralformulaandstateatroomtemperatureandpressureofethene,propene,but-1-eneandbut-2-ene;

2.5.13 describethecompleteandincompletecombustionofalkenes;

2.5.14 demonstrateknowledgeandunderstandingthatafunctionalgroupisareactivegroupinamolecule,recognisethefunctionalgroupsofalkenes,alcoholsandcarboxylicacids,andrecognisethatalkanesdonothaveafunctionalgroupandsoarelessreactive;

2.5.15 recallanddescribetheadditionreactionacrossaC=Cdoublecovalentbond,includingthereactionofethenewithbromine,hydrogenandsteam(nameofthebromoproductisnotrequired);

2.5.16 determinethepresenceofaC=Cusingbrominewater;

2.5.17 describehowmonomers,forexampleetheneorchloroethene(vinylchloride),canjointogethertoformverylongchainmoleculescalledpolymersandrecallthattheprocessisknownasadditionpolymerisation;

2.5.18 writeequationsforthepolymerisationofetheneandchloroethene;and

2.5.19 deducethestructureofanadditionpolymerfromasimplealkenemonomerandviceversa.


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Content

LearningOutcomes



2.5.20 demonstrateknowledgeandunderstandingthatadditionpolymersarenon-biodegradableandevaluatetheadvantagesanddisadvantagesoftheirdisposalbylandfillandincineration;

2.5.21 recallthegeneralformulaofthealcoholsandthe

molecularformula,structuralformulaandstateat roomtemperatureandpressureofmethanol,ethanol, propan-1-olandpropan-2-ol;

2.5.22 describethecompleteandincompletecombustionof

alcohols;

2.5.23 describethepreparationofethanolfromsugarsby fermentation(equationforfermentationofsugarsis notrequired),includingtheconditionsrequired;

2.5.24 recalltheoxidationofalcoholswhenexposedtoair

andbythereactionwithacidifiedpotassium dichromatesolution(equationsarenotrequired)and demonstrateunderstandingthatmethanol,ethanol andpropan-1-olareoxidisedtothecorresponding carboxylicacid(studentsshouldknowthat propan-2-olcanbeoxidisedbutdonotneedtoknow thenameorstructureoftheproduct);

2.5.25 recallthemolecularformula,structuralformula,state

atroomtemperatureandpressureofthecarboxylic acids:methanoicacid,ethanoicacid,propanoicacid andbutanoicacid;

2.5.26 demonstrateknowledgethatcarboxylicacidsareweak

acidsastheyareonlypartiallyionisedinsolution;and

2.5.27 investigateexperimentallythereactionsofcarboxylicacidswithcarbonates,hydroxidesandmetals,testanygasesproducedandwritebalancedsymbolequationsforthesereactions.


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Content

LearningOutcomes



2.5.28 demonstrateknowledgethatthecombustionoffuelsisamajorsourceofatmosphericpollutiondueto:• combustionofhydrocarbonsproducingcarbondioxide,whichleadstothegreenhouseeffectcausingsealevelrises,floodingandclimatechange;

• incompletecombustionproducingcarbonmonoxide(toxic)andsoot(carbonparticles),whichcauselungdamage;and

• presenceofsulfurimpuritiesinfuels,whichleadstoacidraindamagingbuildings,destroyingvegetationandkillingfish;

2.5.29 identifyalkanes,alkenes,alcoholsandcarboxylicacidsusingchemicaltests(otherpracticalactivity);

• investigatethereactionsofcarboxylicacids(Prescribed PracticalC7);

2.6Quantitativechemistry

2.6.1 calculatetheconcentrationofasolutioninmol/dm3giventhemassofsoluteandvolumeofsolution;

2.6.2 calculatethenumberofmolesormassofsolutein

agivenvolumeofsolutionofknownconcentration;2.6.3 demonstrateknowledgeandunderstandingthatthe

volumesofacidandalkalisolutionsthatreacttogethercanbemeasuredbytitrationusingphenolphthaleinormethylorange;

2.6.4 carryoutacid–basetitrationsusinganindicatorand

recordresultstoonedecimalplace,repeatingforreliabilityandcalculatingtheaveragetitrefromaccuratetitrations(detailsofthepracticalprocedureandapparatuspreparationarerequired);and

2.6.5 collectdatafromprimaryandsecondarysourcesforacid–basetitrationandusethisdatatocalculatetheconcentrationsofsolutionsinmol/dm3andg/dm3.


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Content

LearningOutcomes

2.6Quantitativechemistry(cont.)


2.6.6 calculateconcentrationsofsolutionsandsolution volumesinanacid–basetitration,identifyunknown compoundsanddeterminethedegreeofhydration;

2.6.7 recallthatthevolumeofonemoleofanygasatroom temperatureandpressure(20°Cand1atmosphere pressure)is24dm3;2.6.8 recallanduseAvogadro’sLawasequalvolumesof

gasesatthesametemperatureandpressurecontain thesamenumberofparticles/molecules;

2.6.9 calculatethevolumesofgaseousreactantsand

productsfromthebalancedequationforareaction;2.6.10 calculatetheatomeconomyofareactiontoform

adesiredproductfromthebalancedequation:

massofdesiredproduct totalmassofproducts

2.6.11 demonstrateknowledgeandunderstandingthatahighatomeconomyisimportantforsustainabledevelopmentandeconomicreasons;

• determinethereactingvolumesofsolutionsofacidandalkalibytitrationanddeterminetheconcentrationofsolutionsofacidandalkalibytitration(PrescribedPracticalC8);

2.7Electrochemistry

2.7.1 explainthemeaningofthetermselectrolysis,inertelectrode,anode,cathodeandelectrolyteandexplainconductioninanelectrolyteintermsofionsmovingandcarryingcharge;and

2.7.2 predicttheproductsofelectrolysisofmoltensaltsincludinglithiumchlorideandlead(II)bromideusinggraphiteelectrodesandstateappropriateobservationsattheelectrodes.

×100atomeconomy=


34

Content

LearningOutcomes

2.7Electrochemistry(cont.)


2.7.3 interpretandwritehalfequationsforthereactionsoccurringattheanodeandcathodefortheelectrolysisprocesseslistedin2.7.2,forothermoltenhalidesandintheextractionofaluminium;

2.7.4 recalltheproductsofelectrolysisofdilutesulfuricacidusinginertelectrodesandthehalfequationsforthereactionsoccurringattheanodeandthecathode;

2.7.5 describetheindustrialextractionofaluminiumfromalumina,demonstrateknowledgeandunderstandingthatthealuminahasbeenpurifiedfromtheorebauxiteanddemonstrateknowledgeandunderstandingoftheneedtoreplacetheanodesperiodically;

2.7.6 demonstrateknowledgeandunderstandingthatrecyclingaluminiumusesonlyafractionoftheenergyneededtoextractitfrombauxiteandsaveswaste;

2.8Energychangesinchemistry

2.8.1 demonstrateknowledgeandunderstandingthatchemicalreactionsinwhichheatisgivenoutareexothermicandthatreactionsinwhichheatistakeninareendothermic;

2.8.2 drawandinterpretreactionprofilediagramsfor

exothermicandendothermicreactionsidentifyingactivationenergy;

2.8.3 explainactivationenergyastheminimumenergyneededforareactiontooccur;

2.8.4 recallthatbondbreakingtakesinenergyandbondmakingreleasesenergy,anddemonstrateunderstandingthattheoverallenergychangeinareactionisabalanceoftheenergytakeninwhenbondsbreakinthereactantsandtheenergyreleasedwhenbondsformintheproducts;and

2.8.5 calculateenergychangesinachemicalreactionfrombondenergiesbyconsideringbondmakingandbondbreakingenergies.


35

Content

LearningOutcomes

2.9Gaschemistry


2.9.1 recallthecompositionofthegasesintheatmosphere:• about78%nitrogen;• about21%oxygen;• about0.03–0.04%carbondioxide;• about1%argon;• smallproportionsofothernoblegases;and• varyingproportionsofwatervapour;

2.9.2 recallthephysicalpropertiesofnitrogenanddescribe

itslackofreactivityduetoitstriplecovalentbond;2.9.3 demonstrateknowledgeandunderstandingofusing

nitrogenasacoolantandinfoodpackaging;2.9.4 demonstrateknowledgeandunderstandingofthetest

forammonia,usingaglassroddippedinconcentratedhydrochloricacid,andrecalltheuseofammoniainthemanufactureoffertilisersbyitsreactionwithacids;

2.9.5 describethelaboratorypreparationandcollectionof

hydrogenusingzinc(orothersuitablemetal)andhydrochloricacid,andrecallthephysicalpropertiesofhydrogenanditsuses,includingweatherballoonsandhardeningoils,anditspotentialasacleanfuel;


oxygenbythecatalyticdecompositionofhydrogenperoxide,andrecallthephysicalpropertiesofoxygenanditsusesinmedicineandwelding;

2.9.7 describethereactionofcarbon,sulfur,magnesium,

ironandcopperwithoxygenandclassifytheproductsasacidicorbasic;and


carbondioxidegasusingcalciumcarbonateandhydrochloricacid,andrecalltheusesofcarbondioxideinfizzydrinksandfireextinguishers.


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Content

LearningOutcomes

2.9Gaschemistry(cont.)


2.9.9 investigatethechemicalreactionsofcarbondioxidewithwaterproducingcarbonicacidandwithcalciumhydroxide(limewater)untilcarbondioxideisinexcess;and

• investigatethepreparation,properties,testsandreactionsofthegaseshydrogen,oxygenandcarbondioxide(PrescribedPracticalC9).


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3.3 Unit 3: Practical Skills Units1and2includeanumberofpracticaltasksthatstudentscarryoutduringthecourse.Nineoftheseareprescribedpracticals.Thisunithastwoparts:BookletAandBookletB.Wesetandmarkbothbooklets.BookletAisapracticalskillsassessment.Itassessesstudents’abilitytocarryouttwopracticaltasksbasedonbutnotidenticaltothenineprescribedpracticalslistedinthisspecification.BookletBisawritten,externallyassessedexaminationtakenduringthefinalyearofstudy.Itassessesstudents’knowledgeandunderstandingofpracticalscience.Itconsistsofquestionsaboutplanningandcarryingoutanyoftheprescribedpracticaltasks,togetherwithmoregeneralquestionsaboutanypracticalsituationthatarisesinUnits1and2inthisspecification.


Planninganinvestigation


• identifythedependent,independentandcontrolledvariablesinaninvestigation(ifappropriate);

• suggestahypothesisforinvestigationinthecontextofHowScienceWorks;

• planamethodtoallowahypothesistobetestedortoallowananalysistobecarriedout;

• carryoutariskassessmentonallplannedpracticalactivities;• selectequipmentorapparatusthatissuitableandwillcontributetoobtainingaccurate results;

• producearesultstablewithappropriateheadings(andunitsifappropriate)forrecordingawiderangeofappropriaterawdataincludingobservationsanddeductions;

• drawadiagramoftheapparatususedinanexperiment;and• demonstrateknowledgeandunderstandingofthestepsthatmustbetakentoensurethevalidityofthepracticalprocessandthereliabilityofdatacollected(ifappropriate).


38


Carryingoutanexperiment


• demonstratethepracticalskillsnecessarytousethefollowingapparatuscorrectly,skilfullyandsafely:− Bunsenburnerandassociatedapparatussuchasheatproofmat,tripod,gauze,pipeclaytriangle,crucibleandevaporatingbasin/dish;

− generalglasswaresuchasbeakers,conicalflasks,testtubes,boilingtubes,glassrod,pipettes(disposableplasticpipettesmaybeused),filterfunnels,watchglassandcombustiontubes;

− gaspreparationapparatusincludinggasjarandlid,thistlefunnel,deliverytubes,beehiveshelfandtrough(orbasin);

− electrolysisequipmentincludinggraphiteelectrodes,electricalwires,crocodileclipsandd.c.powersupply;

− graduatedglassware(volume)suchasmeasuringcylindersofvaryingsizes;

− titrationapparatusincludingatleastclassBbulbpipettesandburettes(volume),buretteholder/clampandwhitetile;

− gassyringe;− electronicbalance(mass);− ruler(length);− stopclockorstopwatch(time);− thermometerorsensor(temperature);and– anyotherappropriateapparatus.


39


Analysingexperimentaldata


• recorddetailedobservationsornumericaldata(whereappropriate)duringchemicalreactions,includingdiscreteorcontinuousvariables;

• demonstrateknowledgeandunderstandingofthedifferencesbetweenaccuracy(practicaltechniquesorapparatusthathelpstoensureaccuracy),reliability(reproducibilityofresults)andvalidity(whethertheexperimentissuitableforthetask);

• demonstrateknowledgeandunderstandingofthemathematicaltechniquesthatcanbeusedtoidentifytherelationshipsbetweenvariables;

• useappropriatescalesandaxeslabelswhenplottingagraphofexperimentaldata;

• demonstrateknowledgeandunderstandingofwhatismeantbyananomalousresultinasetofexperimentaldataandhowitshouldbetreated;

• plotdatapointsaccuratelyanddrawtheappropriatestraightlineorcurve;

Drawingconclusionsfromanexperiment

• makereasonedjudgementsanddrawevidence-basedconclusions;

• analyse,interpretandcriticallyevaluateabroadrangeofexperimentaldata;

• makedeductionsfromgivenobservations;• usereliablenumericaldatatocarryoutappropriatecalculationsofmoles,mass,percentagebymass,gasvolume,concentration,solutionvolume,degreeofhydrationandanyotherappropriatequantity;and

• demonstrateunderstandingthatforagraphofyagainstx,astraightlinethrough(0,0)isanindicatorofdirectproportion.


40


Drawingconclusionsfromanexperiment(cont.)


• demonstrateunderstandingthatforagraphofyagainst1/x,astraightlinethrough(0,0)isanindicatorofinverse(indirect)proportion;

• discussindetailtheareasofaninvestigationthatcouldaffectthereliabilityofthedataorevidencecollected;

• developanddefendahypothesiswithappropriateanddetailedscientificreasoning;and

• developargumentsandexplanations,takingaccountofthelimitationsoftheavailableevidence.


41


Prescribedpracticals

BelowisalistofprescribedpracticalsthatmaybeassessedinUnit3.Studentsshouldbeableto:

• determinethemassofwaterpresentinhydratedcrystals(PrescribedPracticalC1);

• investigatethereactionsofacids,includingtemperaturechangesthatoccur(PrescribedPracticalC2);

• investigatethepreparationofsolublesalts(PrescribedPracticalC3);

• identifytheionsinanioniccompoundusingchemicaltests(PrescribedPracticalC4);

• investigatethereactivityofmetals(PrescribedPracticalC5);• investigatehowchangingavariablechangestherateofreaction(PrescribedPracticalC6);

• investigatethereactionsofcarboxylicacids

(PrescribedPracticalC7);

• determinethereactingvolumesofsolutionsofacidandalkalibytitrationanddeterminetheconcentrationofsolutionsofacidandalkalibytitration(PrescribedPracticalC8);and

• investigatethepreparation,properties,testsandreactionsofthegaseshydrogen,oxygenandcarbondioxide(PrescribedPracticalC9).


42

4 Scheme of Assessment 4.1 Assessment opportunities Fortheavailabilityofexaminationsandassessment,seeSection2.Thisisaunitisedspecification;candidatesmustcompleteatleast40percentoftheoverallassessmentrequirementsattheendofthecourse,intheexaminationseriesinwhichtheyrequestafinalsubjectgrade.Thisistheterminalrule.Candidatesmayresitindividualassessmentunitsoncebeforecash-in.ThebetterofthetworesultswillcounttowardstheirfinalGCSEgradeunlessaunitisrequiredtomeetthe40percentterminalrule.Ifitis,themorerecentmarkwillcount(whetherornotitisthebetterresult).ResultsforindividualassessmentunitsremainavailabletocounttowardsaGCSEqualificationuntilwewithdrawthespecification.4.2 Assessment objectives Therearethreeassessmentobjectives(AO1,AO2andAO3)forthisspecification.Candidatesmust:

AO1 demonstrateknowledgeandunderstandingof:• scientificideas;and• scientifictechniquesandprocedures;

AO2 applyknowledgeandunderstandingofanddevelopskillsin:• scientificideas;and• scientificenquiry,techniquesandprocedures;and

AO3 analysescientificinformationandideasto:• interpretandevaluate;• makejudgementsanddrawconclusions;and• developandimproveexperimentalprocedures.

4.3 Assessment objective weightings ThetablebelowsetsouttheapproximateassessmentobjectiveweightingsforeachassessmentcomponentandtheoverallGCSEqualification.

AssessmentObjective

UnitWeighting(%) OverallWeighting

(%)Unit1 Unit2 Unit3

AO1 15 16 9 40

AO2 15 17 8 40

AO3 5 7 8 20

TotalWeighting 35 40 25 100


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4.4 Quality of written communication InGCSEChemistry,candidatesmustdemonstratetheirqualityofwrittencommunication.Theyneedto:

• ensurethattextislegibleandthatspelling,punctuationandgrammarareaccuratesothatmeaningisclear;

• selectanduseaformandstyleofwritingthatsuittheirpurposeandcomplexsubjectmatter;and

• organiseinformationclearlyandcoherently,usingspecialistvocabularywhereappropriate.

Qualityofwrittencommunicationisassessedinresponsestoquestionsandtasksthatrequireextendedwriting.Units1,2andBookletBofUnit3eachhaveonequestionthathas6marksallocatedtoacandidate’squalityofwrittencommunication.Thesequestionsaremarkedusingathreetierbandedmarkschemethatstipulatestheminimumnumberofmarksrequiredforeachband.Qualityofwrittencommunicationisthenassessedwithineachindividualband.

4.5 Reporting and grading Wereporttheresultsofindividualassessmentunitsonauniformmarkscalethatreflectstheassessmentweightingofeachunit.Wedeterminethegradesawardedbyaggregatingtheuniformmarksthatcandidatesobtaininindividualassessmentunits.WeawardGCSEqualificationsonagradescalefromA*toG,withA*beingthehighest.Theninegradesavailableareasfollows:Grade A* A B C* C D E F GIfcandidatesfailtoattainagradeGorabove,wereporttheirresultasunclassified(U).


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5 Grade Descriptions Gradedescriptionsareprovidedtogiveageneralindicationofthestandardsofachievementlikelytohavebeenshownbycandidatesawardedparticulargrades.Thedescriptionsmustbeinterpretedinrelationtothecontentinthespecification;theyarenotdesignedtodefinethatcontent.Thegradeawardeddependsinpracticeupontheextenttowhichthecandidatehasmettheassessmentobjectivesoverall.Shortcomingsinsomeaspectsofcandidates’performanceintheassessmentmaybebalancedbybetterperformancesinothers.

Grade

Description

A Candidatesrecall,selectandcommunicatepreciseknowledgeanddetailedunderstandingofchemistry.Theydemonstrateacomprehensiveunderstandingofthenatureofchemistry,itslaws,itsprinciplesandapplicationsandtherelationshipbetweenchemistryandsociety.Theyunderstandtherelationshipsbetweenscientificadvances,theirethicalimplicationsandthebenefitsandrisksassociatedwiththem.Theyusescientificandtechnicalknowledge,terminologyandconventionsappropriatelyandconsistently,showingadetailedunderstandingofscaleintermsoftime,sizeandspace.Theyapplyappropriateskills,includingcommunication,mathematical,technicalandobservationalskills,knowledgeandunderstandingeffectivelyinawiderangeofpracticalandothercontexts.Theyshowacomprehensiveunderstandingoftherelationshipsbetweenhypotheses,evidence,theoriesandexplanationsandmakeeffectiveuseofmodels,includingmathematicalmodels,toexplainabstractideas,phenomena,eventsandprocesses.Theyuseawiderangeofappropriatemethods,sourcesofinformationanddataconsistently,applyingrelevantskillstoaddressscientificquestions,solveproblemsandtesthypotheses.Candidatesanalyse,interpretandcriticallyevaluateabroadrangeofquantitativeandqualitativedataandinformation.Theyevaluateinformationsystematicallytodevelopargumentsandexplanations,takingaccountofthelimitationsoftheavailableevidence.Theymakereasonedjudgementsconsistentlyanddrawdetailed,evidence-basedconclusions.


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Grade

Description

C

Candidatesrecall,selectandcommunicatesecureknowledgeandunderstandingofchemistry.Theydemonstrateunderstandingofthenatureofchemistry,itslaws,itsprinciplesandapplicationsandtherelationshipbetweenchemistryandsociety.Theyunderstandthatscientificadvancesmayhaveethicalimplications,benefitsandrisks.Theyusescientificandtechnicalknowledge,terminologyandconventionsappropriately,showingunderstandingofscaleintermsoftime,sizeandspace.Theyapplyappropriateskills,includingcommunication,mathematical,technicalandobservationalskills,knowledgeandunderstandinginarangeofpracticalandothercontexts.Theyshowunderstandingoftherelationshipsbetweenhypotheses,evidence,theoriesandexplanationsandusemodels,includingmathematicalmodels,todescribeabstractideas,phenomena,eventsandprocesses.Theyusearangeofappropriatemethods,sourcesofinformationanddata,applyingtheirskillstoaddressscientificquestions,solveproblemsandtesthypotheses.Candidatesanalyse,interpretandevaluatearangeofquantitativeandqualitativedataandinformation.Theyunderstandthelimitationsofevidenceanduseevidenceandinformationtodevelopargumentswithsupportingexplanations.Theydrawconclusionsbasedontheavailableevidence.


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Grade

Description

F Candidatesrecall,selectandcommunicatelimitedknowledgeandunderstandingofchemistry.Theyrecognisesimpleinterrelationshipsbetweenchemistryandsociety.Theyshowalimitedunderstandingthatscientificadvancesmayhaveethicalimplications,benefitsandrisks.Theyuselimitedscientificandtechnicalknowledge,terminologyandconventions,showingsomeunderstandingofscaleintermsoftime,sizeandspace.Theyapplyskills,includinglimitedcommunication,mathematical,technicalandobservationalskills,knowledgeandunderstandinginpracticalandsomeothercontexts.Theyrecogniseandusehypotheses,evidenceandexplanationsandcanexplainstraightforwardmodelsofphenomena,eventsandprocesses.Theyusealimitedrangeofmethods,sourcesofinformationanddatatoaddressstraightforwardscientificquestions,problemsandhypotheses.Candidatesinterpretandevaluatelimitedquantitativeandqualitativedataandinformationfromanarrowrangeofsources.Theycandrawelementaryconclusionshavingcollectedlimitedevidence.


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6 Guidance on Practical Skills Assessment 6.1 Overview Unit3assessespracticalskills.Ithastwoparts:BookletAisapracticalskillsassessmentandBookletBisanexamination.Allofthenineprescribedpracticalsshouldbetaughtthroughoutthecourse.BookletAconsistsoftwopre-releasepracticalassessmenttasksbasedonbutnotidenticaltothoseonthelistofnineprescribedpracticals.Wechangethetwoassessedpracticalseveryyeartoensurethattheycontinuetosetanappropriatechallengeandremainvalid,reliableandstimulating.ForBookletA,candidatescarryouttwopracticaltasksinthelaboratory.BookletAisapracticalskillsassessmentandshouldbecarriedoutunderahighlevelofcontrol,withteacherandinvigilatorsupervisiontocomplywithhealthandsafetyregulations.WesendcentresalistofthematerialsrequiredforBookletAintheDecemberbeforetheSummersubmission.WesendBookletAtocentresinJanuaryofthefinalyearofstudy.Candidatescollectqualitativeorquantitativeresultsdependingonthedemandsofthepracticalskillsassessment.Wewillpublishatimetabledperiodforthispracticalskillsassessmentontheexaminationstimetable.CentresmustsendBookletAtousformarking.BookletBisatimetabled,externallyassessedexaminationtakenattheendofthefinalyearofstudy.Itconsistsofquestionsaboutplanningandcarryingoutanyoftheprescribedpracticaltasks.Italsohasmoregeneralquestionsaboutanypracticalsituationthatarisesfromthisspecification.6.2 Skills assessed by Unit 3 Thefollowingskillsareassessed:

• planninganinvestigation;• carryingoutanexperiment;• analysingexperimentaldata;and• drawingconclusionsfromanexperiment.


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6.3 Task taking in Booklet A BookletAisapracticalskillsassessmentandmustbecarriedoutunderahighlevelofcontrol.

Anappropriateteachershouldbepresentwithaninvigilatortoensurecompliancewithhealthandsafetyregulations.

TeachersandinvigilatorsshouldnotofferdirectionorguidancetocandidateswherethiswouldassistthemincompletingBookletA.

Candidatesmayworkcollaborativelyingroupsofuptothreewhencarryingoutthepracticaltasks,buttheymustworkindividuallyandindependentlytocompleteBookletA.

Candidateshave2hourstocompleteBookletA,anditmustbecompletedinasinglesession.FoundationandHigherTiercandidatesmaycarryoutthepracticalskillsassessmentinthesameroombutcanonlyworkwithotherstakingthesametier.TheexaminationsofficermustkeepallBookletApapers(completedandunused)securelyatalltimes.

CentresmustreturnBookletApaperstousformarkingafter1May.

WewillprovideadditionalinformationrelatingtoBookletAasasupportdocument.


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ForBookletA,thelevelofcontrolfortasktakingishigh.Thetablebelowexemplifieshighlevelsofcontrolforthispracticalskillsassessment.

AreasofControl DetailofControl

Authenticity • BookletAisanexternallysetandexternallymarkedpracticalskillsassessment.

• Teachersmustensurethatallcandidatesareindirectsightofthesupervisoratalltimes.

• Interactionbetweencandidatesistightlyprescribedduringthepracticaltasks.

• TheyshouldnotcommunicatewitheachotherwhencompletingtheirresponseinBookletA.

• Wewillpublishatimetabledperiodforthispracticalskillsassessmentontheexaminationstimetable.

• CandidatesmustcarryoutthepracticaltasksandcompleteBookletAin2hours.

• WesendanapparatusandmaterialslisttoexaminationsofficersinDecemberofthefinalyearofstudy.Theyshoulddistributethislisttotherelevantheadofdepartment.

Feedback • Teachersshouldnotprovideguidanceorfeedbackduringthepracticalskillsassessmentexcepttointerveneonthegroundsofhealthandsafety.

PageLimit • WesetBookletA.Ithasnoprescribedpagelimit.

Collaboration • Candidatesforthesametierofentrymayworkcollaborativelytocarryoutthepracticaltasks,buttheymustprovideanindividualresponseinBookletA.

Resources • TheonlyallowedadditionalresourceistheGCSEDataLeafletthatappearsinAppendix3,ifrequired.

Forup-to-dateadviceonplagiarism,oranykindofcandidatemalpractice,seeSuspectedMalpracticeinExaminationsandAssessments:PoliciesandProceduresontheJointCouncilforQualificationswebsiteatwww.jcq.org.uk6.4 Task marking Ourexaminersmarkthetasks.


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7 Curriculum Objectives ThisspecificationbuildsonthelearningexperiencesfromKeyStage3asrequiredforthestatutoryNorthernIrelandCurriculum.ItalsooffersopportunitiesforstudentstocontributetotheaimandobjectivesoftheCurriculumatKeyStage4,andtocontinuetodeveloptheCross-CurricularSkillsandtheThinkingSkillsandPersonalCapabilities.Theextentofthedevelopmentoftheseskillsandcapabilitieswillbedependentontheteachingandlearningmethodologyused.7.1 Cross-Curricular Skills at Key Stage 4

Communication


• communicatemeaning,feelingsandviewpointsinalogicalandcoherentmanner,forexampleoutlineexamplesofhowmodernlifeisdependentonhydrocarbonsandcrudeoil;

• makeoralandwrittensummaries,reportsandpresentations,takingaccountofaudienceandpurpose,forexampleproduceapresentationontheimportanceofnanomaterialsandtheiruses,includingbenefitsandrisks;

• participateindiscussions,debatesandinterviews,forexampledebatedisposingofpolymersbyincinerationorlandfill,ordiscusstheenvironmentaleffectsoffossilfuelcombustion;

• interpret,analyseandpresentinformationinoral,writtenandICTformats,forexampleprepareaPowerPointpresentationoraposteraboutacidrainanditscauses,itsenvironmentalimpactandsociety’sresponsibilitytominimiseitonaninternationalscale;and

• exploreandrespond,bothimaginativelyandcritically,toavarietyoftexts,forexamplereviewseveralarticlesabouttheuseofcatalystsinindustrialprocesses.


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UsingMathematics


• usemathematicallanguageandnotationwithconfidence,forexampleuseappropriateunits,measurementsandcalculationstodeterminemass,degreeofhydration,concentration,empiricalformulaoridentityofanunknowncompound;

• usementalcomputationtocalculate,estimateandmakepredictionsinarangeofsimulatedandreal-lifecontexts,forexampleestimatetemperaturechangesduringneutralisationanddisplacementreactions;

• selectandapplymathematicalconceptsandproblem-solvingstrategiesinarangeofsimulatedandreal-lifecontexts,forexampleapplythegeneralformulaforahomologousseriesandapplythisdeterminedformulatocombustionreactions;

• interpretandanalyseawiderangeofmathematicaldata,forexamplecomparepHvaluestoidentifysubstancesasbeingstrongorweakacidsoralkalis;

• assessprobabilityandriskinarangeofsimulatedandreal-lifecontexts,forexampleassessriskthroughriskassessmentofpracticalactivities;and

• presentmathematicaldatainavarietyofformatswhichtakeaccountofaudienceandpurpose,forexamplepresenttablesoftitrationresultsandusestandardform.

UsingICT

Studentsshouldbeabletomakeeffectiveuseofinformationandcommunicationstechnologyinawiderangeofcontextstoaccess,manage,selectandpresentinformation,includingmathematicalinformation,forexampleuseaspreadsheettoplotratesofreactiondatafromavarietyofgroupscarryingoutexperimentswithdifferentconcentrationsofasolutionsuchashydrochloricacid.


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7.2 Thinking Skills and Personal Capabilities at Key Stage 4

Self-Management


• planwork;• setpersonallearninggoalsandtargetstomeetdeadlines;• monitor,reviewandevaluatetheirprogressandimprovetheirlearning;and• effectivelymanagetheirtime,forexamplecarryoutanindividualprojectorassignmentthatcollatesthedataonreactionsofmetalswithairandwithwater,alongwithdisplacementreactionscarriedoutinclass,todevelopareactivityseries.

WorkingwithOthers


• learnwithandfromothersthroughco-operation;• participateineffectiveteamsandacceptresponsibilityforachievingcollectivegoals;and

• listenactivelytoothersandinfluencegroupthinkinganddecision-making,takingaccountofothers’opinions,forexampleinvestigatethereactionsofacidswithmetals,metaloxides,metalhydroxidesandmetalcarbonatesasacircuitofexperimentsthatarecombinedtoconsolidatetheoutputoftheobservationsandequationsforthereactionsinvolved.


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AlthoughnotreferredtoseparatelyasastatutoryrequirementatKeyStage4intheNorthernIrelandCurriculum,ManagingInformationandBeingCreativemayalsoremainrelevanttolearning.

ProblemSolving


• identifyandanalyserelationshipsandpatterns,forexampleinterpretdatatodetermineandstatetrendssuchasthereactivityofmetalsorsolubility;

• proposejustifiedexplanations,forexampledeterminetheidentityofcationsandanionsfromtheobservationsofprecipitationreactionsandflametests;

• analyseandevaluatemultipleperspectives,forexampleevaluatetheideaofyieldversusrateinindustrialprocessesasachemicalengineerasopposedtoachemistinmaximisingprofit;

• exploreunfamiliarviewswithoutprejudice,forexampleresearchtheuseofnanomaterials,includingtheirbenefits,risksandwithdrawal;

• weighupoptionsandjustifydecisions,forexampleoutlinetheadvantagesanddisadvantagesofrecyclingaluminiumwhencomparedtoextractionfromaluminiumore;and

• applyandevaluatearangeofapproachestosolveproblemsinfamiliarandnovelcontexts,forexampleexploresaltpreparationmethods.


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8 Links and Support 8.1 Support Thefollowingresourcesareavailabletosupportthisspecification:

• ourChemistrymicrositeatwww.ccea.org.ukand• specimenassessmentmaterials.Wealsointendtoprovide:

• pastpapers;• markschemes;• ChiefExaminer’sreports;• PrincipalModerator’sreports;• guidanceonprogressionfromKeyStage3;• planningframeworks;• centresupportvisits;• supportdaysforteachers;• practicalskillsassessmentguidanceforteachers;• practicalskillsassessmentguidanceforcandidates;• aresourcelist;and• exemplificationofexaminationperformance.8.2 Examination entries EntrycodesforthissubjectanddetailsonhowtomakeentriesareavailableonourQualificationsAdministrationHandbookmicrosite,whichyoucanaccessatwww.ccea.org.ukAlternatively,youcantelephoneourExaminationEntries,ResultsandCertificationteamusingthecontactdetailsprovided.8.3 Equality and inclusion Wehaveconsideredtherequirementsofequalitylegislationindevelopingthisspecificationanddesignedittobeasfreeaspossiblefromethnic,sexualorientation,gender,religious,politicalandotherformsofbias.GCSEqualificationsoftenrequiretheassessmentofabroadrangeofcompetences.Thisisbecausetheyaregeneralqualificationsthatpreparestudentsforawiderangeofoccupationsandhigherlevelcourses.Duringthedevelopmentprocess,anexternalequalitypanelreviewedthespecificationtoidentifyanypotentialbarrierstoequalityandinclusion.Whereappropriate,wehaveconsideredmeasurestosupportaccessandmitigatebarriers.


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Wecanmakereasonableadjustmentsforstudentswithdisabilitiestoreducebarrierstoaccessingassessments.Forthisreason,veryfewstudentswillhaveacompletebarriertoanypartoftheassessment.Studentswithaphysicalimpairmentmayinstructapracticalassistanttosetupequipmentbutmayhavedifficultyinmakingobservationsandinmanipulatingtheequipmenttocarryouttheexperiment.Studentswithavisualimpairmentmayfindelementsoftheassessmentdifficult,buttechnologymayhelpvisuallyimpairedstudentstotakereadingsandmakeobservations.Therefore,theassessmentsshouldnotposeadifficultyforthesestudents.Itisimportanttonotethatwhereaccessarrangementsarepermitted,theymustnotbeusedinanywaythatunderminestheintegrityoftheassessment.YoucanfindinformationonreasonableadjustmentsintheJointCouncilforQualificationsdocumentAccessArrangementsandReasonableAdjustments,availableatwww.jcq.org.uk


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8.4 Contact details Ifyouhaveanyqueriesaboutthisspecification,pleasecontacttherelevantCCEAstaffmemberordepartment:

• SpecificationSupportOfficer:NualaTierney(telephone:(028)90261200,extension2292,email:[email protected])

• SubjectOfficer:ElaineLennox(telephone:(028)90261200,extension2320,email:[email protected])

• ExaminationEntries,ResultsandCertification(telephone:(028)90261262,email:[email protected])

• ExaminerRecruitment(telephone:(028)90261243,email:[email protected])

• Distribution(telephone:(028)90261242,email:[email protected])

• SupportEventsAdministration(telephone:(028)90261401,email:[email protected])

• Moderation(telephone:(028)90261200,extension2236,email:[email protected])

• BusinessAssurance(ComplaintsandAppeals)(telephone:(028)90261244,email:[email protected]@ccea.org.uk).


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Appendix 1 Mathematical Content ThemathematicsthatmustformpartofGCSEChemistryshouldbeatlevelsupto,butnotbeyond,therequirementsspecifiedinGCSEMathematicsfortheappropriatetier.Thisspecificationensuresthatthenumberofmarksusedtocredittherelevantmathematicalskillsisnolessthan20percentofthetotalmarksforthequalification.Studentsneedtobefamiliarwithandcompetentinthefollowingareasofmathematicstodeveloptheirskills,knowledgeandunderstandinginChemistry.

MathematicalSkills

Arithmeticandnumericalcomputation

Recogniseanduseexpressionsindecimalform

Recogniseanduseexpressionsinstandardform

Useratios,fractionsandpercentages

Makeestimatesoftheresultsofsimplecalculations

Handlingdata

Useanappropriatenumberofsignificantfigures

Findarithmeticmeans

Understandtheprinciplesofsamplingasappliedtoscientificdata

Understandthetermmean(average)

Useascatterdiagramtoidentifyacorrelationbetweentwovariables

Makeorderofmagnitudecalculations

Algebra

Changethesubjectofanequation

Substitutenumericalvaluesintoalgebraicequationsusingappropriateunitsforphysicalquantities

Solvesimplealgebraicequations

Graphs

Translateinformationbetweengraphicalandnumericform

Plottwovariablesfromexperimentalorotherdata


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Physical quantities, units and unit abbreviations Thetablebelowgivesthephysicalquantities,unitsandabbreviationscommonlyusedforGCSEChemistry.Studentsshouldalsounderstandtheprefixesfemto(f),pico(p),nano(n),milli(m),centi(c),deci(d)andkilo(k)whereappropriate.

PhysicalQuantity Unit AbbreviationforUnit

Amount mole mol

Concentration molepercubicdecimetregrampercubicdecimetre

mol/dm3g/dm3

Energy joulekilojoule

JkJ

Length metrecentimetremillimetrenanometrepicometrefemtometrekilometre

mcmmmnmpmfmkm

Mass gramkilogramtonne

gkgt

Pressure atmosphere atm

Temperature degreeCelsius °C

Time secondminutehour

sminh

Volume cubicdecimetrecubiccentimetrecubicmetre

dm3cm3

m3


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Appendix 2How Science Works Weassessstudents’practicalskillsthroughwrittenexaminationsandpracticalassessments.Thisspecificationemphasisestheimportanceofpracticalwork.ThecontentinthisspecificationisassessedinthecontextofHowScienceWorksandassessesstudents’abilitiesinthefollowingskills.


• understandhowscientificmethodsandtheoriesdevelopovertime;

• useavarietyofmodelssuchasrepresentational,spatial,descriptive,computationalandmathematicaltosolveproblems,tomakepredictionsandtodevelopscientificexplanationsandunderstandingoffamiliarandunfamiliarfacts;

• appreciatethepowerandlimitationsofscienceandconsideranyethicalissuesthatmayarise;

• explaineverydayandtechnologicalapplicationsofscience,evaluateassociatedpersonal,social,economicandenvironmentalimplicationsandmakedecisionsbasedontheevaluationofevidenceandarguments;

• evaluaterisksbothinpracticalscienceandinthewidersocietalcontext,includingperceptionofriskinrelationtodataandconsequences;

• recognisetheimportanceofpeerreviewofresultsandofcommunicatingresultstoarangeofaudiences;

• usescientifictheoriesandexplanationstodevelophypotheses;• planexperimentsordeviseprocedurestomakeobservations,produceorcharacteriseasubstance,testhypotheses,checkdataorexplorephenomena;

• applyknowledgeofarangeoftechniques,instruments,apparatusandmaterialstoselectthoseappropriatetotheexperiment;

• carryoutexperimentswiththeappropriatemanipulationofapparatus,takingaccuratemeasurementsandconsideringhealthandsafety;

• recognisewhentoapplyknowledgeofsamplingtechniquestoensureanysamplescollectedarerepresentative;and

• makeandrecordobservationsandmeasurementsusingarangeofapparatusandmethods.


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• evaluatemethodsandsuggestpossibleimprovementsandfurtherinvestigations;

• presentobservationsandotherdatausingappropriatemethods;• translatedatafromoneformtoanother;• carryoutandrepresentmathematicalandstatisticalanalysis;• representthedistributionofresultsandmakeestimationsofuncertainty;• interpretobservationsandotherdata(presentedinverbal,diagrammatic,graphical,symbolicornumericalform),includingidentifyingpatternsandtrends,makinginferencesanddrawingconclusions;

• presentreasonedexplanationsincludingrelatingdatatohypotheses;• beobjective,evaluatedataintermsofaccuracy,precision,repeatabilityandreproducibilityandidentifypotentialsourcesofrandomandsystematicerror;

• communicatethescientificrationaleforinvestigations,methodsused,findingsandreasonedconclusionsthroughwrittenandelectronicreportsandpresentationsusingverbal,diagrammatic,graphical,numericalandsymbolicforms;

• usescientificvocabulary,terminologyanddefinitions;• recognisetheimportanceofscientificquantitiesandunderstandhowtheyaredetermined;

• useSIunits(forexamplekg,g,mg;km,m,mm;kJ,J)andIUPACchemicalnomenclatureifappropriate;

• useprefixesandpowersof10forordersofmagnitude(forexampletera,giga,mega,kilo,centi,milli,micro,nano,picoandfemto);

• interconvertunits;and• useanappropriatenumberofsignificantfiguresincalculations.


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Appendix 3Data Leaflet including the Periodic Table of the Elements Thisdataleafletisforusewiththespecimenassessmentmaterials.Thesameinformationwillbeprovidedwithliveexaminationpapersandmaybesubjecttoupdatesasrequired.


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ccea gcse specification in - chemistry

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