CambridgeInternationalExaminations

CambridgeInternationalAdvancedSubsidiaryandAdvancedLevel

CHEMISTRY 9701/36

Paper3AdvancedPracticalSkills2 October/November2014

INSTRUCTIONS

Greatcareshouldbetakentoensurethatanyconfidentialinformationgivendoesnotreachthecandidateseitherdirectlyorindirectly.

TheSupervisor’sattentionisdrawntotheformonpage7whi ustbecompletedandreturnedwiththescripts.

IfyouhaveanyproblemsorqueriesregardingtheseInstructions,pleasecontactCIEby :

info@.uk,

byphone: 4,

byfax 8,

statingtheCentrenumber,thenatureofthequeryandthesyllabusnumberquotedabove.

This consistsof8printedpages.

IB1411_9701_36CI/5RP

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Safety

Supervisorsareadvisedtoremindcandidatesthatallsubstancesintheexaminationshouldbetreatedwithcaution.

Onlythosetestsdescribedinthequestionpapershouldbeattempted.Pleasealsoseeunder‘Apparatus’ontheuseofpipettefillers,safetygogglesandsticgloves.

InaccordancewithCOSHH(ControlofSubstancesHazardoustoHealth)Regulations,operativeintheUK,ahazardappraisaloftheexaminationhasbeencarriedout.

Attentionisdrawninparticular,tocertainmaterialsusedintheexamination.Thefollowingcodesareusedwhererelevant.

C corrosivesubstance F highlyflblesubstance

H harmfulorirritatingsubstance O oxidisingsubstance

T toxicsubstance N dangerousfortheenvironmentTheattentionofSupervisorsisdrawntoanylocalregulationsrelatingtosafetyandfirst-aid.

‘HazardDataSheets’,relatingtomaterialsusedinthiamination,shouldbeavailablefromyourchemicalr.

BeforetheExamination

AccesstothequestionpaperisNOTpermittedinadvanceoftheexamination.

Preparationofmaterials

Wheretiesarespecifiedforeachcandidate,theyaresufficientfortheexperimentsdescribedinthequestionpapertobecompleted.

Inpreparingmaterials,thebulktyforeachsubstanceshouldbeincreasedby25%assparematerialshouldbeavailabletocoveraccidentalloss.Morematerialmaybedifrequestedbycandidates,withoutpenalty.

Allsolutionsshouldbebulkedandmixedthoroughlybeforeusetoensureuniformity.

Everyeffortshouldbemadetokeeptheconcentrationsaccuratetowithinonepartintwohundredofthosespecified.

Supervisorsareaskedtocarryoutanyconfirmatorytestsgivenonpage4toensurethematerialsdareappropriate.

Iftheconcentrationsdifferslightlyfromthosespecified,theExaminerswillmakethenecessaryallowance.Theyshouldbeinformedoftheexactconcentrations.

Labellingofmaterials

Materialsmustbelabelledasspecifiedintheseinstructions.MaterialswithanFBcodenumbershouldbesolabelledwithouttheidentitiesbeingincludedonthelabel.WhereappropriatetheidentityofanFBcodedchemicalisgiveninthequestionpaperitself.

Identityofmaterials

ItshouldbenotedthatdescriptionsofsolutionsgiveninthequestionpapermaynotcorrespondexactlywiththespecificationsintheseInstructions.Thecandidatesmustassumethedescriptionsgiveninthequestionpaper.

Sizeofgroup

Inviewofthedifficultyofthepreparationoflargetiesofsolutionofuniformconcentration,itis mendedthattheumnumberofcandidatespergroupbe30andthatseparatesofsolutionsbepreparedforeachgroup.

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Apparatus

Inadditiontothefittingsordinarilycontainedinachemicallaboratory,theapparatusandmaterialsspecifiedbelowwillbenecessary.

Pipettefillers(orequivalentsafetydevices),safetygogglesanddisposableglovesshouldbeusedwherenecessary.

Foreachcandidate

125cm3pipette

110cm3pipette

250cm3burettes

1funnel(forfillingburette)

2burettestandsandclamps2250cm3conicalflasks

1whitetile

2100cm3beakers

1250cm3beaker

125cm3measuringcylinder

1stopwatch(orsightofclockreadingto1second)1glassrod

1Bunsenburner

1tripodandgauze1heatproofmat

1thermometer(–10Cto+110C,at1C)1test-tubeholder

1hard-glasstest-tube6test-tubes*

1boilingtube*1test-tuberack

1spatula

2teat/droppipettes

1washbottlecontainingdistilledwaterpapertowels

*Candidatesareexpectedtorinseandre-usetest-tubesandboilingtubeswherepossible.Additionaltest-tubesshouldbeavailable.

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ChemicalsRequired

Itisespeciallyimportantthatgreatcareistakenthattheconfidentialinformationgivenbelowdoesnotreachthecandidateseitherdirectlyorindirectly.

Particularrequirements

hazard

label

percandidate

identity

notes

(hazardsgiveninthiscolumnarefortherawmaterials)

FB1

250cm3

0.100moldm–3sodiumthiosulfate

Dissolve24.8gofNa2S2O3.5H2Oineachdm3ofsolution.Note:FB6couldbepreparedusingthissolution.

FB2

150cm3

aqueouspotassiumiodate(V)containing3.60gdm–3

Dissolve3.60gofKIO3[O]ineachdm3ofsolution.

[H]

FB3

150cm3

1.0moldm–3sulfuricacid

Seepreparationinstructionsonpage59ofthe2014syllabus.

FB4

180cm3

1.00moldm–3potassiumiodide

Dissolve166.1gofKIineachdm3ofsolution.

starchindicator

20cm3

starchindicator

Seepreparationinstructionsonpage60ofthe2014syllabus.Thisshouldbefreshlyprepared.

FB5

120cm3

0.0200moldm–3potassiumperoxodisulfate

Dissolve5.41gofK2S2O8[H][O]ineachdm3ofsolution.rSsowmilelrefertothisaspotassiumpersulfate.

FB6

80cm3

0.0100moldm–3sodiumthiosulfate

Prepare0.100moldm–3bydissolving24.8gofNa2S2O3.5H2Oineachdm3ofsolution.Dilutethissolutionusing100cm3toproduceeach1dm3.

distilledwater

100cm3

distilledwater

FB7

10cm3

0.050moldm–3manganese(II)chloride

Dissolve9.90gofMnCl2.4H2O[H]or8.10gMnCl2.2H2O[H]ineachdm3ofsolution.Thisshouldbeprovidedinastopperedcontainer.

[N]

FB8

10cm3

0.020moldm–3potassiummanganate(VII)

Seepreparationinstructionsonpage60ofthe2014syllabus.Thisshouldbeprovidedinastopperedcontainer.

[F][H]

ethanol

2cm3

ethanol

[F]

magnesiumribbon

2cmlength

magnesiumribbon

[H]

FB9

2g

copper(II)carbonate

Ayp2pgrooxfimcoapper( II)carbonateshouldbeprovidedinastopperedcontainer.BasiccoppercarbonateCuCO3.Cu(OH)2[H]issuitable.

FB10

10cm3

0.10moldm–3copper(II)sulfate

Dissolve25.0gCuSO4.5H2O[H][N]ineachdm3ofsolution.Thisshouldbeprovidedinastopperedcontainer.

[C]

concentratedhydrochloricacid

2cm3

concentratedhydrochloricacid

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Thereagentsbelowshouldalsobeprovided.Unlessotherwisestated,eachcandidateshouldrequirenomorethan10cm3ofanyofthesereagents.Ifnecessary,theymaybemadeavailablefromacommunalsupply:however,theattentionoftheInvigilatorsshouldbedrawntothefactthatsuchanarrangementmayleadtocontaminationofreagentsandenhancetheopportunityformalpracticebetweencandidates.

hazard

label

percandidate

identity

notes

[H]

dilutehydrochloricacid

Seeidentitydetailsandpreparationinstructionsonpages59and60ofthe2014syllabus.

[C]

dilutenitricacid

[H]

dilutesulfuricacid

[H]

aqueousammonia

[C]

aqueoussodiumhydroxide

[H]

0.1moldm–3bariumchlorideor

0.1moldm–3bariumnitrate

[H][N]

0.05moldm–3silvernitrate

[H]

limewater

hydrogenperoxide

5cm3

10volH2O2

[H][N]

acidifiedaqueouspotassiummanganate(VII)

Mixequalvolumesof0.02moldm–3KMnO4[N]and1.0moldm–3sulfuricacid[H].

Thefollowingmaterialsandapparatusshouldbeavailable.

rinedandbluelitmuspapers,

filterpaperstripsforusewithacidifiedmanganate(VII),aluminiumfoilfortestingnitrate/nitrite,woodensplints

andtheapparatusnormallyusedintheCentreforusewithlimewaterintestingforcarbondioxide

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ResponsibilitiesoftheSupervisorduringtheExamination

TheSupervisor,orothercompetentchemist,must,outofsightofthecandidates,carryouttheexperimentsinQuestion1andQuestion2andcompletetablesofreadingsonasparecopyofthequestionpaperwhichshouldbelabelled‘Supervisor’sResults’.

Thisshouldbedonefor:

eachsessionheldandeachlaboratoryusedinthatsession,andeachsetofsolutionsd.

N.B.Thequestionpapercoverrequeststhecandidatetofillindetailsoftheexaminationsessionandthelaboratoryusedfortheexamination.

ItisessentialthateachpacketofscriptscontainsacopyoftheapplicableSupervisor’sResultsasthecandidates’workcannotbeassessedaccuraywithoutsuchinformation.

TheSupervisormustcompletetheReportFormonpage7toshowwhichcandidatesattendedeachsession.Ifallcandidatestooktheexaminationinonesession,pleaseindicatethisontheReportForm.AcopyoftheReportFormmust panyeachcopyoftheSupervisor’sResultsinorderforthecandidates’worktobeassessedaccuray.

TheSupervisormustgivedetailsonpage8ofanyparticulardifficultie periencedbyacandidate,especiallyiftheExaminerwouldbeunabletodiscoverthisfromthewrittenanswers.

AftertheExamination

EachenvelopereturnedtoCambridgemustcontainthefollowingitems.

Thescriptsofthosecandidatesspecifiedonthebarcodelabelprovided.

AcopyoftheSupervisor’sReportrelevanttothecandidatesin1.

AcopyoftheReportForm,includingdetailsofanydifficultieperiencedbycandidates(seepages7and8).

TheAttendanceRegister.

ASeating nforeachsession/laboratory.

Failuretoprovideappropriateationineachenvelopemaycausecandidatestobepenalised.

COLOUR-BLINDNESS

Withregardtocolour-blindnessitispermissibletoadvisecandidateswhorequestassistanceoncoloursof,forexampleprecipitatesandsolutions(especiallytitrationend-points).Pleaseincludewiththescriptsanoteofthecandidatenumbersofsuchcandidates.

Experiencesuggeststhatcandidateswhoarered/greencolour-blind–themostcommonform–donotgenerallyhavesignificantdifficulty.Reportingsuchcaseswiththescriptsremovestheneedfora‘SpecialConsideration’application.

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REPORTFORM

ThisformmustbecompletedandsenttotheExaminerintheenvelopewiththescripts.

CentreNumberNameofCentre

Supervisor’sResults

PleasesubmitdetailsofthereadingsobtainedinQuestion1andQuestion2onasparecopyofthequestionpaperclearlymarked‘Supervisor’sResults’andshowingtheCentrenumberandappropriatesession/laboratorynumber.

Thecandidatenumbersofcandidatesattendingeachsessionwere:

FirstSession SecondSession

TheSupervisorisrequiredtogivedetailsoverleafofanydifficultie periencedbyparticularcandidates,givingnamesandcandidatenumbers.Theseshouldincludereferenceto:

anygeneraldifficultiesencounteredinmakingpr