2019 Chemistry Written examination

CHEMISTRYWritten examination

Tuesday 12 November 2019 Reading time: 9.00 am to 9.15 am (15 minutes) Writing time: 9.15 am to 11.45 am (2 hours 30 minutes)

QUESTION AND ANSWER BOOK

Structure of bookSection Number of

questionsNumber of questions

to be answeredNumber of

marksA 30 30 30B 10 10 90

Total 120

• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers, sharpeners,rulersandonescientificcalculator.

• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.

Materials supplied• Questionandanswerbookof42pages• Databook• Answersheetformultiple-choicequestionsInstructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname andstudent numberasprintedonyouranswersheetformultiple-choice

questionsarecorrect,andsignyournameinthespaceprovidedtoverifythis.• Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.• AllwrittenresponsesmustbeinEnglish.At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.• Youmaykeepthedatabook.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2019

SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2019

STUDENT NUMBER

Letter

2019CHEMISTRYEXAM 2

SECTION A – continued

do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

eaQuestion 1

AnunderstandingofLeChatelier’sprincipleisusefulinthechemicalindustry.ThepredictionthatcanbemadeusingthisprincipleistheeffectofA. catalystsontherateofreaction.B. catalystsonthepositionofequilibrium.C. changesintemperatureontherateofreaction.D. changesintheconcentrationofreactantsonthepositionofequilibrium.

Question 2ThethermochemicalequationforthecompletecombustionofglucoseisA. C6H12O6+6O2 →6CO2+6H2O ΔH=−2860kJmol−1

B. C6H12O6+3O2 →6CO+6H2O ΔH=−2011kJmol−1

C. C6H12O6 →2C2H5OH+2CO2 ΔH=−69kJmol−1

D. C6H12O6 →2C3H6O3 ΔH=−120kJmol−1

Question 3Acompoundhasthefollowingskeletalformula.

O

ThemolarmassofthecompoundisA. 71gmol−1

B. 74gmol−1

C. 85gmol−1

D. 86gmol−1

SECTION A – Multiple-choice questions

Instructions for Section AAnswerall questionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrect orthatbest answers thequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.

3 2019CHEMISTRYEXAM

SECTION A – continuedTURN OVER

do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 4OxidativeranciditycanbesloweddownbyaddingA. heat.B. ultraviolet(UV)light.C. sodiumions.D. areducingagent.

Question 5Atthestartoftheday,astudentsetupagalvaniccellusingtwoelectrodes:nickel,Ni,andmetalX.Thisset-upisshowninthediagrambelow.

V

Ni(s) X(s)salt bridge

Ni2+(aq) X2+(aq)

Half-cell 1 Half-cell 2

greensolution

ConsiderthefollowingalternativemetalsthatcouldbeusedtoreplacemetalX:

1.zinc,Zn 2.lead,Pb 3.cadmium,Cd 4.copper,Cu

Attheendoftheday,thestudentcheckedthecolourofthesolutioninHalf-cell1andobservedthatthesolutionwasadarkergreencolour.WhichofthealternativemetalscouldcausethecolourofHalf-cell1tobecomeadarkergreen?A. metals1and3B. metals2and4C. metals1,2and3D. metals3and4

2019CHEMISTRYEXAM 4


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 6Whichoneofthefollowingstatementsaboutenzymesiscorrect?A. Theinducedfitmodelsuggeststhattheshapeofanenzymeremainsconstantthroughoutacatalysedreaction.B. Enzymesmayhavetheirtertiarystructurealteredduringacatalysedreaction.C. Enzymescancatalysemostreactionsoverabroadrangeoftemperatures.D. Enzymesmaychangetheequilibriumconstantofacatalysedreaction.

Question 7Amoltenmixtureofequalpartsaluminiumfluoride,AlF3,andsodiumchloride,NaCl,undergoeselectrolysis.Whichoneofthefollowingstatementsaboutthisreactioniscorrect?A. Sodiummetalwillbeproducedatthecathodeandfluorinegaswillbeproducedattheanode.B. Sodiummetalwillbeproducedattheanodeandchlorinegaswillbeproducedatthecathode.C. Aluminiummetalwillbeproducedatthecathodeandchlorinegaswillbeproducedattheanode.D. Aluminiummetalwillbeproducedattheanodeandfluorinegaswillbeproducedatthecathode.

Question 8Considerthefollowingstatementsaboutgalvaniccellsandfuelcells.

Statement number Statement

1 Theoverallreactionisexothermic.

2 Electronsareconsumedatthenegativeelectrode.

3 Boththereducingagentandtheoxidisingagentarestoredineachhalf-cell.

4 Theelectrodesareincontactwiththereactantsandtheelectrolyte.

5 Theproductionofelectricityrequirestheelectrodestobereplacedregularly.

Whichoneofthefollowingsetsofstatementsiscorrectforbothgalvaniccellsandfuelcells?A. statementnumbers2and3B. statementnumbers1and4C. statementnumbers2,4and5D. statementnumbers1,3and5

5 2019CHEMISTRYEXAM


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 9Areactionhastheenergyprofilediagramshownbelow.

1201101009080706050403020100

enthalpy(kJ mol–1)

progress of reaction

Whichofthefollowingrepresentstheenergyprofileofthereversereaction?

Final product energy (kJ mol−1)

ΔH (kJ mol−1)

A. 40 +10

B. 50 +10

C. 50 −10

D. 40 −10

Question 10Whichoneofthefollowingstatementsaboutcoenzymesiscorrect?A. Coenzymesalterthesecondarystructureofenzymes.B. Coenzymescanreactwithenzymestoproduceproteins.C. Coenzymescanbindtoenzymestomakeareactionoccur.D. Thetertiarystructureofcoenzymespreventsthemfrombindingwithenzymes.

Question 115mLofethanol,CH3CH2OH,undergoescombustioninatesttubewithadiameterof1cm.Thisexperimentisperformedinafumecupboard.Thetemperatureinthefumecupboardis20°C.Whichoneofthefollowingactionswillreducetherateofreaction?A. Mix2mLofadilutesolutionofsodiumhydroxide,NaOH,withtheethanol.B. Performtheexperimentinatesttubewithadiameterof2cm.C. Increasethetemperatureinthefumecupboardto25°C.D. Increasethevolumeoftheethanolto7mL.

2019 CHEMISTRY EXAM 6


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 12A compound has the molecular formula C4H9Cl.Which type of chemical analysis would be most useful in determining whether this compound has a stereoisomer? A. mass spectrometry B. infra-red spectroscopyC. high-performance liquid chromatographyD. nuclear magnetic resonance spectroscopy

Question 13Which one of the following statements about flashpoints is correct?A. The flashpoint of butane is lower than 25 °C.B. As a flashpoint increases, the viscosity decreases.C. The flashpoint of a compound is higher than its boiling point.D. The flashpoint of butane is greater than the flashpoint of butan-1-ol.

Question 14The following diagram represents the structure of a non-essential vitamin.

H3C

H3C

O

O

O

O

CH3

CH3

H

10

This vitamin isA. fat-soluble and can be produced by the human body.B. water-soluble and can be produced by the human body.C. fat-soluble and cannot be produced by the human body.D. water-soluble and cannot be produced by the human body.

Question 15 Aspartame has onlyA. one chiral centre.B. two stereoisomers.C. four optical isomers. D. three structural isomers.

7 2019CHEMISTRYEXAM


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 16Thenumberofcarbon-to-carbondoublebonds(C=C)inamoleculecanbeidentifiedbyreactingthemoleculewithhydrogengas,H2.Thetypeofreactioninvolvedisanadditionreaction.10.0gofafattyacidbecomesfullysaturatedafterreactingwith0.263gofH2.ThefattyacidisA. oleicacid(M=282gmol−1).B. linolenicacid(M=278gmol−1).C. arachidicacid(M=312gmol−1).D. arachidonicacid(M=304gmol−1).

Question 17Thetraditionofbronzingbabyshoesdatesbackforgenerations.Beforeelectroplating,theshoeispaintedwithaconductivematerial.Thecopper,Cu,electrodeandcoppersulfate,CuSO4,solutioncellusedforelectroplatingashoeisshownbelow.

CuSO4(aq)

Cu electrode

DuringtheelectroplatingprocessA. thecopperelectrodeisoxidisedanditsmassisunchanged.B. theshoeiscoatedwithcoppermetalatthecathode.C. thecopperelectrodeistheoxidisingagent.D. oxygenisproducedatthecathode.

2019CHEMISTRYEXAM 8


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 18Whichoneofthefollowinggalvaniccellswillproducethelargestcellvoltageunderstandardlaboratoryconditions(SLC)?

salt bridge

Zn Ni

1.0 M Zn(NO3)2 1.0 M Ni(NO3)2

salt bridge

Fe Pt

1.0 M Fe(NO3)2 1.0 M HCl

salt bridge

Ag Cu

1.0 M AgNO3 1.0 M Cu(NO3)2

salt bridge

Sn Pt

1.0 M Sn(NO3)2 pure water

A. B.

C. D.

9 2019CHEMISTRYEXAM


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

Question 19Lactoseiscommonlyfoundinmilkandmilkproducts.Theenzymeusedtohydrolyselactoseinthehumansmallintestineislactase.Lactoseintolerancedescribesthelimitedabilityofhumanstohydrolyselactose.Considerthefollowingstatements.

Statement number Statement

1 Lactose-intolerantpeopleproducetoomuchlactaseenzyme.

2 Insufficientlactaseleadstosomelactosenotundergoinghydrolysisinthehumanbody.

3 Lactose-intolerantpeoplecanaddlactasedropstomilktohelpdigestion.

4 Lactaseassistsinthehydrolysisoflactoseintotwoglucosemolecules.

Whichoneofthefollowingsetsofstatementsiscorrect?A. statementnumbers1,2and3B. statementnumbers1,2and4C. statementnumbers2and3D. statementnumbers3and4

Question 20Theoxidationofsulfurdioxide,SO2,tosulfurtrioxide,SO3,canberepresentedbythefollowingequation.

2SO2(g)+O2(g)⇌2SO3(g) Kc=1.75M−1at1000°C

Anequilibriummixturehasaconcentrationof0.12MSO2and0.16Moxygengas,O2.Thetemperatureofthecontaineris1000°C.TheequilibriumconcentrationofSO3at1000°CisA. 1.5×10−4MB. 4.0×10−3MC. 1.2×10−2MD. 6.3×10−2M

2019CHEMISTRYEXAM 10

do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION A–continued

Question 21ThediagrambelowrepresentstheMaxwell-Boltzmanndistributionofanuncatalysedreaction.

number of particles

Eakinetic energy

Theeffectofaddingacatalystcouldbe:1. thecurveflattenstoreflecttheloweractivationenergybarrier2. thecurveshiftstotheright3. theEashiftstotheleft.

Whichofthestatementsabovearecorrect?A. 1onlyB. 1and2C. 2and3D. 3only

Question 22Whichoneofthefollowingstatementsaboutconductinganexperimentisthemostcorrect?A. Preciseresultsmaybebiased.B. Accuracyisassuredifsensitiveinstrumentsareused.C. Amethodisvalidifitidentifiesallcontrolledvariables.D. Repeatingaprocedurewillremovetheuncertaintyoftheresults.

Question 23Whichoneofthefollowingstatementsaboutenthalpychangeiscorrect?A. Thesignoftheenthalpychangeforanendothermicreactionisnegative.B. Thesignoftheenthalpychangeforthecondensationofagastoaliquidisnegative.C. Theenthalpychangeisthedifferencebetweentheactivationenergyandtheenergyofthereactants.D. Theenthalpychangeisthedifferencebetweentheactivationenergyandtheenergyoftheproducts.

11 2019CHEMISTRYEXAM

do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION A–continuedTURN OVER

Question 24Thediagrambelowshowsanelectroplatingcell.

object

power source

metalelectrode

Thecellcontains1Lofanelectroplatingsolution.Theelectroplatingcellisrunforonehourat3A.Whichoneofthefollowingelectroplatingsolutionswilldepositthelargestmassofmetalontotheobject?A. 1MAgNO3

B. 1MCd(NO3)2C. 1MPb(NO3)2D. 1MAl(NO3)3


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION A–continued

Question 25Thefollowingconcentration–timegraphreferstoamixtureofthreegases,P,QandR,inanenclosed5.0Lcontainer.Attimet1themixtureisheated.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

t1

concentration (M)

time (seconds)

Q

P

R

TheequilibriumsystemthatrepresentsthegraphisA. P(g) ⇌2Q(g)+R(g)andtheforwardreactionisexothermic.B. 2Q(g)⇌P(g)+R(g)andtheforwardreactionisendothermic.C. 2Q(g)+R(g)⇌P(g)andtheforwardreactionisexothermic.D. P(g)+2Q(g) ⇌R(g)andtheforwardreactionisendothermic.

Question 26Thecalibrationfactorofabombcalorimeterwasdeterminedbyconnectingthecalorimetertoapowersupply.Thecalibrationwasdoneusing100mLofwater,6.5Vandacurrentof3.6Afor4.0minutes.Thetemperatureofthewaterincreasedby0.48°Cduringthecalibration.4.20gofsucroseunderwentcompletecombustioninthebombcalorimeter.Thetemperatureofthe100mLofwaterincreasedfrom19.6°Cto25.8°C.M(C12H22O11)=342gmol−1

Theexperimentalheatofcombustionofpuresucrose,injoulespergram,isA. 5.9×106

B. 7.3×104

C. 1.7×104

D. 1.2×104


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION A–continuedTURN OVER

Question 27Anorganiccompoundhasamolarmassof88gmol−1.The13CNMRspectrumoftheorganiccompoundshowsfourdistinctpeaks.TheorganiccompoundismostlikelyA. butan-1-ol.B. 2-methyl-butan-1-ol.C. 2-methyl-butan-2-ol.D. 2,2-dimethyl-propan-1-ol.

Question 28Theconcentrationofallofthegasesintheequilibriumreactionsbelowis1.0M.

Reaction1 CH4(g)+2H2O(g)⇌CO2(g)+4H2(g)

Reaction2 N2(g)+3H2(g)⇌2NH3(g)

Reaction3 H2(g)+I2(g)⇌2HI(g)

Reaction4 2NO2(g)⇌N2O4(g)

InwhichreactiondoesKc=1.0M−2?A. Reaction1B. Reaction2C. Reaction3D. Reaction4


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

END OF SECTION A

Use the following information to answer Questions 29 and 30.TheconcentrationofvitaminCinafilteredsampleofgrapefruitjuicewasdeterminedbytitratingthejuicewith 9.367×10−4Miodine,I2,solutionusingstarchsolutionasanindicator.ThemolarmassofvitaminCis 176.0gmol−1.Thereactioncanberepresentedbythefollowingequation.

C6H8O6(aq)+I2(aq)→C6H6O6(aq)+2H+(aq)+2I−(aq)

Thefollowingmethodwasused:1. Weighaclean250mLconicalflask.2. Usea10mLmeasuringcylindertomeasure5mLofgrapefruitjuiceintotheconicalflaskandreweighit.3. Add20mLofdeionisedwatertotheconicalflask.4. Addadropofstarchsolutiontotheconicalflask.5. TitratethedilutedgrapefruitjuiceagainsttheI2solution.

Question 29WhichoneofthefollowingerrorswouldresultinanunderestimationoftheconcentrationofvitaminCingrapefruitjuice?A. 19mLofdeionisedwaterwasaddedtotheconicalflask.B. TheconcentrationoftheI2solutionwasactually9.178×10−4M.C. TheinitialvolumeoftheI2solutionintheburettewas1.50mL,butitwasreadas2.50mL.D. Thebalancewasfaultyandthemeasuredmassofgrapefruitjuicewaslowerthantheactualmass.

Question 30Ifthemeasuredmassofgrapefruitjuicewas4.90gandthetitrewas21.50mL,whatwasthemeasuredpercentagemass/mass(%m/m)concentrationofvitaminCinthegrapefruitjuice?A. 0.00987B. 0.0723C. 0.354D. 3.36


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

TURN OVER

CONTINUES OVER PAGE


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – Question 1–continued

Question 1 (9marks)Acommercialchocolatespreadiscommonlyusedinsandwichesanddesserts.Thisfoodcontainshighamountsofproteins,triglyceridesandsucrose.Proteinsareanimportantpartoffood.Proteinsarebrokendownintosmallermoleculesduringdigestion.

a. Proteinscanbehydrolysedtoproducealpha(α-)aminoacids.

Identifyonestructuralfeaturecommontoallalpha(α-)aminoacids. 1mark

b. i. Whatistheprocessbywhichaminoacidsareobtainedfromthechocolatespread? 1mark

ii. Identifythechemicalprocessinwhichaminoacidsarepredominantlyusedinthebody. 1mark

iii. Twooftheaminoacidsinthechocolatespreadareasparticacidandcysteine.

DrawthechemicalstructureofthedipeptideCys-Aspathigh pH. 2marks

SECTION B

Instructions for Section BAnswerallquestionsinthespacesprovided.Writeusingblueorblackpen.Givesimplifiedanswerstoallnumericalquestions,withanappropriatenumberofsignificantfigures;unsimplifiedanswerswillnotbegivenfullmarks.Showallworkinginyouranswerstonumericalquestions;nomarkswillbegivenforanincorrectanswerunlessitisaccompaniedbydetailsoftheworking.Ensurechemicalequationsarebalancedandthattheformulasforindividualsubstancesincludeanindicationofstate,forexample,H2(g),NaCl(s).Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – continuedTURN OVER

c. Thetriglyceridesinthechocolatespreadcontainpalmiticacidandpalmitoleicacid.

Whichofthesefattyacidsislikelytohaveahighermeltingpoint?Explainyourreasoning. 2marks

d. Drawthestructureofatriglyceridethatcontainsonlypalmitoleicacidusingsemi-structuralformulas.Circleandlabelthetriglyceridefunctionalgroup. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 2 (8marks)a. ThefollowingdiagramrepresentsareactionpathwayforthesynthesisofCompoundQfrom

pent-2-ene.

pent-2-ene

Skeletal formula:

Compound M(contains a chiral carbon)

Name:

Compound Q

Semi-structural formula:

Cr2O72–/H+

H2O/H+

Compound N(no chiral carbon)

i. Drawtheskeletalformulaforpent-2-eneintheboxprovided. 1mark

Twostructuralisomersarepossiblewhenpent-2-eneishydrolysedatahightemperatureinthepresenceofanacidcatalyst.CompoundsMandNareformed.CompoundMhasachiralcarbon,butCompoundNdoesnot.

ii. GivetheIUPACnameofCompoundMintheboxprovided. 1mark

iii. WhenCompoundMisreactedwithacidifieddichromateions,Cr2O72−,CompoundQisformed.

Drawthesemi-structuralformulaofCompoundQintheboxprovided. 1mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


b. 2-chloropropanecanbereactedwithammoniatoproduceanunchargedorganicmolecule,CompoundR.

i. Writetheequationforthereactionthatoccurs. 1mark

ii. GivetheIUPACnameofCompoundR. 1mark

iii. NamethetypeofreactionthatproducesCompoundR. 1mark

iv. CalculatethepercentageatomeconomyfortheproductionofCompoundR. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 3 (7marks)Thecobalt(II)tetrachlorideion,CoCl42−,dissociatesintothecobalt(II)ion,Co2+,andchlorideions,Cl−,accordingtothefollowingchemicalequation.

CoCl42−(aq)⇌Co2+(aq)+4Cl−(aq)

blue pink

20mLsamplesoftheequilibriummixturewereheatedtotwotemperatures,30°Cand80°C.TheintensityofthepinkcolouroftheCo2+productwasrecordedevery30secondsbymeasuringtheabsorbanceofthesolution.Thehighertheintensityofthepinkcolour,thehighertheabsorbance.Theresultsofthisexperimentareshowninthegraphbelow.

30 °C

80 °Crelative

absorbance

time (seconds)

a. Statewhethertheforwardreactionisexothermicorendothermic.Justifyyouranswerbyreferringtothegraph. 2marks

b. When5mLofwaterwasaddedtotheequilibriummixture,thecolourofthesolutionimmediatelybecamealighterpink.

Describethefinalcolourofthesolutiononceequilibriumisre-established.Explainyouranswer. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


c. Fivedropsofsilvernitrate,AgNO3,solutionareaddedtotheequilibriummixtureattimet1. Aconcentration–timegraphforthisreactionisshownbelowfortimesbetweenzeroandt1.

concentration (M)

t1time (arbitrary units)

CoCl42–

Cl–

Co2+

0

Continuethegraphtoshowthechangesthatoccurtothesystemfromt1untilequilibriumis re-established. 3marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 4 (7marks)Internalcombustionenginesareusedinlargenumbersofmotorvehicles.Historically,internalcombustionengineshaveusedfuelsobtainedfromcrudeoilasasourceofpower.Asconcernsfortheenvironmenthavegrown,effortshavebeenmadetoobtainfuelforcombustionenginesfromothersources.

a. Onewayofreducingtheenvironmentaleffectsoffossilfuelsistoblendthemwithbiofuels.Acommonmethodistoblendpetrolwithethanolinvaryingratios.Afuelcanbeobtainedbyblending 1moleofoctane,C8H18,and1moleofethanol,C2H5OH.

Thechemicalequationforthecompletecombustionofthisfuelmixtureis

C8H18(l)+C2H5OH(l)+15½O2(g)→10CO2(g)+12H2O(g)

Calculatetheenergyreleased,inkilojoules,when80gofthisfuelmixtureundergoescompletecombustion.Showyourworking. 3marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


b. Somecarmanufacturersareexploringtheuseofanacidicethanolfuelcelltopowervehicles.Inthisfuelcell,theethanolatoneelectrodereactswithwaterthathasbeenproducedattheotherelectrode. Amembraneisusedtotransportionsbetweentheelectrodes.Adiagramofanacidicethanolfuelcellisshownbelow.

O2

excessO2

CH3CH2OH

excessCH3CH2OH

H2OCO2

membrane

load

i. Identifytheelectrodeaseitherthecathodeortheanodeintheboxprovidedinthediagramabove. 1mark

ii. Writethehalf-equationforthereactionoccurringattheanode. 1mark

iii. Thecombustionofethanolandthecombustionofoctanereleaseaboutthesameamountofenergypermoleofcarbondioxideproduced.

Identifytwoadvantagesofpoweringavehicleusinganethanolfuelcellinsteadofaninternalcombustionenginepoweredbyoctane. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 5 (8marks)High-performanceliquidchromatography(HPLC)wasusedtodeterminethesucroseconcentrationinasampletakenfromacanofsoftdrink.Standardsolutionsweremadeupusingpuresucroseanddeionisedwater.A1mLsampleofeachstandardsolutionwasinjectedintotheHPLCcolumnanditspeakareawasrecorded,asshowninthetablebelow.

Concentration of sucrose (g L−1)

Peak area (mm2)

0.10 700

0.20 1600

0.40 2500

0.60 3300

0.80 4200

Theexperimentalresults(shownasdots)andacalibrationlineoftheconcentrationofsucroseagainstpeakareaareshowninthegraphbelow.

4500

4000

3500

3000

2500

2000

1500

1000

500

0

peak area (mm2)

0 0.10 0.20 0.30 0.40concentration (g L–1)

0.50 0.60 0.70 0.80 0.90


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – Question 5–continuedTURN OVER

a. A5.0mLsampleofthesoftdrinkwasdilutedto100mLinavolumetricflask. A10.0mLaliquotofthissolutionwastransferredtoa250mLvolumetricflaskandfilleduptothe

calibrationmarkusingdeionisedwater. AsampleofthissolutionwasinjectedintotheHPLCcolumn.Thepeakareaofthesamplesolutionat

thesameretentiontimeandunderthesameconditionsasthoseusedtodeterminethecalibrationlinewasfoundtobe1900mm2.

i. DeterminethesucrosecontentofthesampletestedintheHPLC,ingramsperlitre. 1mark

ii. Calculatethepercentagemass/volume(%m/v)ofsucroseinthe5.0mLsampleofsoftdrink. 2marks

iii. Thecanusedtoobtainthesamplecontained330mLofsoftdrink.

Assumingthattheonlysugarinthesoftdrinkissucrose,calculatethemassofsucroseinthecanofsoftdrink. 1mark

b. Basedontheresultsobtained,istheexperimentalmethodvalid?Giveyourreasoning. 1mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – continued

c. Sucroseandaspartamearetypesofsweeteners.

Useyourunderstandingofchemistrytoexplainwhysomepeoplereplacesugarwithaspartame.Inyouranswer,comparesucroseandaspartameintermsof:• metabolicreactions• glycaemicindices• energycontent. 3marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – Question 6 – continuedTURN OVER

Question 6 (10marks)TherearemanyvarietiesofbreadavailabletoconsumersinAustralia.Thenutritionalvaluesforonetypeofwholemealbreadaregiveninthetablebelow.

Per 100 g

Energy 1000kJ

Protein 9.1g

Fats and oils 2.5g

Carbohydrates 41.5g

Sugars 3.0g

Fibre 6.4g

a. Calculatetheenergy,inkilojoules,providedbytheproteinandfatsandoilsin100gofthiswholemealbread. 1mark

b. Nameamodelusedtoexplainthemechanismbywhichanenzymecanbreakdownproteins. 1mark

c. Proteinscanbedenaturedbyanincreaseintemperature.

Describewhathappenstothebondingintheproteinstructurewhenitisdenaturedbyanincreaseintemperature. 1mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


d. Carbohydratescanbepresentinthebodyinmanyforms.

i. Namethepolysaccharidethatisusedtostoreenergywithinthebody. 1mark

ii. Explainthedifferenceintheglycaemicindexofamyloseandamylopectin. 2marks

e. Canolaoilisoneoftheusualingredientsinbread.Canolaoilisasourceofomega-3fattyacids.

Whyarethesefattyacidsclassifiedasomega-3? 1mark

29 2019 CHEMISTRY EXAM

do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


f. The wholemeal bread undergoes complete combustion in a bomb calorimeter containing 200 g of water. Assume that all of the energy in the combustion is transferred to the water.

i. Calculate the mass of bread needed to raise the temperature of the water by 6 °C. 2 marks

ii. The combustion of the bread was investigated using a different method. The bread was ignited under a beaker containing 200 g of water, which was set on a tripod. The equipment used is shown below.

water

tripod

stand

watch glass

breadflame

beaker

If 1.2 g of bread was needed to raise the temperature of the water by 6 °C using this different method, calculate the efficiency of the energy transfer in this combustion. 1 mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 7 (8marks)Thezinc–ceriumbatteryisacommercialrechargeablebatterythatcomprisesaseriesofcells.Duringrecharging,thecellsuseenergyfromwindfarmsorsolarcellpanels.Duringdischarging,energyissuppliedtoelectricgridstopowerlocalfactoriesandhomes.Theelectrolytesarestoredinseparatestoragetanks,andarepumpedintoandoutofeachcellwheninuse.Amembraneseparatesthetwoelectrodesthatareimmersedin1Mmethanesulfonicacid,CH3SO3H.Adiagramrepresentingazinc–ceriumcellisshownbelow.

membrane

load

electrolytetank

Ce4+/Ce3+

electrolytetankZn2+

carbon electrode

zinc electrode

pump pump

pump pump

Thefollowinghalf-cellreactionsoccurinthezinc–ceriumcell.

Zn(CH3SO3)2(aq)+2H+(aq)+2e− ⇌Zn(s)+2CH3SO3H(aq) E0=−0.76VCe(CH3SO3)4(aq)+H+(aq)+e− ⇌Ce(CH3SO3)3(aq)+CH3SO3H(aq) E0=1.64V

a. Writetheequationfortheoveralldischargereaction. 1mark

b. Identifytheoxidisingagentduringdischargingandjustifyyouranswerusingoxidationnumbers. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


c. Determinethetheoreticalvoltageproducedbyasinglecellasitdischarges. 1mark

d. Writetheionicequationforthereactionoccurringatthepositiveelectrodeduringrecharging. 1mark

e. Otherthantransportingionsbetweentheelectrodes,describeonefunctionofthemembraneinthezinc–ceriumcell. 1mark

f. Specifyonefactorthatwouldlimitthelifeofthezinc–ceriumcell. 1mark

g. Expertshaveregardedthezinc–ceriumcellasahybridofafuelcellandasecondarycell.

Whywouldthisbethecase? 1mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 8 (9marks)Anunknownorganiccompoundcontainscarbon,hydrogenandoxygen.Itisknownthat:• thecompounddoesnotcontaincarbon-to-carbondoublebonds(C=C)• themolecularionpeakisfoundatamass-to-chargeratio(m/z)of74• the13CNMRhasthreedistinctpeaks.

a. Asmallpeakinthemassspectrumcanbeidentifiedatm/z=75.

Explainthepresenceofthispeak. 1mark

b. i. Usetheinformationprovidedtogivetwopossiblemolecularformulasforthiscompound. 2marks

ii. The1HNMRspectrumofthecompoundshowsthreesetsofpeakswithapeakarearatioof3:2:1.

Whatdoesthisinformationtellyouaboutthestructureofthecompoundanditsmolecularformula?Justifyyouranswerbyreferringtotheinformationgivenaboutthepeaksinthe 1HNMRspectrum. 2marks

c. Therearemanystructuralisomersofthiscompound.

Drawthestructuralformulasoftwopossibleisomers. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


d. Theinfra-red(IR)spectrumofthecompoundisshownbelow.

100

50

0

transmittance (%)

wave number (cm–1)4000 3000 2000 1500 1000 500

BA

Data:SDBSWeb,<http://sdbs.db.aist.go.jp>, NationalInstituteofAdvancedIndustrialScienceandTechnology

i. IdentifythefunctionalgroupsresponsiblefortheabsorptionpeakslabelledAandBinthe IRspectrum. 1mark

A

B

ii. Usingthe1HNMRinformationgiveninpart b.ii.andtheIRspectrumprovidedabove,drawthestructuralformulaofthecompound. 1mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – Question 9 – continued

Question 9 (15 marks)A student designed an experiment to investigate current efficiency during the electrolysis of a sodium chloride, NaCl, solution. Current efficiency is the amount of product produced, expressed as a percentage of the theoretical amount of product, calculated using Faraday’s law. When the products of an electrolysis are gases, current efficiency can be calculated using the following.

current efficiency = volume of gas producedvolume of gas expected baased on Faraday,s law

× 100%

All experimental work was carried out under standard laboratory conditions (SLC). The experiment involved the use of a Hoffman electrolysis apparatus.The following is the first section of the student’s report.

What is the effect on current efficiency during electrolysis when the concentration of a sodium chloride, NaCl, solution is changed?

AimTo investigate the effect on current efficiency during electrolysis when the concentration of a sodium chloride, NaCl, solution is changed

ProcedureStep 1: Rinse the Hoffman electrolysis apparatus with distilled water.Step 2: Fill the Hoffman electrolysis apparatus with distilled water so that the bottom of the meniscus in

both tubes is level with the 170 mL mark.Step 3: Connect the power supply and ammeter to the electrodes of the Hoffman electrolysis apparatus.Step 4: Turn on the power supply and start timing. Record the current displayed on the ammeter.Step 5: After five minutes turn off the power supply and record the volume level on each of the tubes.Step 6: Repeat steps 2–5 four times.Step 7: Average the readings of the initial and final volumes at each electrode and current readings.Step 8: Repeat steps 1–7 using 1.5 M NaCl solution instead of distilled water.Step 9: Repeat steps 1–7 using 4 M NaCl solution instead of distilled water.

a. Identify the dependent variable. 1 mark


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


b. i. Identifyasafetyriskassociatedwiththechemicalsproducedduringtheexperiment. 1mark

ii. Whatarethesafetymeasuresrequiredtoreducethesafetyriskidentifiedinpart b.i.? 1mark

AdiagramoftheHoffmanelectrolysisapparatus,correctlyfilledasrequiredinStep2,isshownbelow.

170 mL

160 mL

150 mL

140 mL

130 mL

120 mL

110 mL

100 mL

90 mL

80 mL

70 mL

60 mL

50 mL

40 mL

30 mL

20 mL

10 mL

0 mL

170 mL

160 mL

150 mL

140 mL

130 mL

120 mL

110 mL

100 mL

90 mL

80 mL

70 mL

60 mL

50 mL

40 mL

30 mL

20 mL

10 mL

0 mL

graphite electrode

powersupply+ –

graphite electrode

stopcock stopcock


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Theresultsforsteps1–7oftheprocedurearegivenbelowinPart1.

Part 1 – Distilled water

Trial Initial volume (mL) Final volume (mL) Current (A)

Negative electrode

Positive electrode

Negative electrode

Positive electrode

1 170.0 170.0 100.2 135.3 2.0

2 170.0 170.0 100.3 135.3 2.0

3 170.0 170.0 99.9 135.0 2.0

4 170.0 170.0 99.8 134.8 2.0

5 170.0 170.0 100.1 135.1 2.0

Average 170.0 170.0 100.1 135.1 2.0

c. AretheresultsinPart1precise?Justifyyouranswer. 1mark

d. Writethehalf-equationforthereactionthatwouldbeexpectedtobeobservedatthenegativeelectrode. 1mark

e. i. CalculatethevolumeofgasexpectedatthenegativeelectrodeforPart1oftheexperimentusingFaraday’slaw. 3marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


ii. CalculatethecurrentefficiencyforPart1oftheexperiment. 1mark

Theresultsforsteps8and9oftheprocedurearegivenbelowinPart2andPart3.

Part 2 – 1.5 M NaCl (Step 8 of the procedure)

Initial volume (mL) Final volume (mL) Current (A)

Negative electrode

Positive electrode

Negative electrode

Positive electrode

Average 170.0 170.0 98.0 133.2 2.0

Part 3 – 4 M NaCl (Step 9 of the procedure)

Initial volume (mL) Final volume (mL) Current (A)

Negative electrode

Positive electrode

Negative electrode

Positive electrode

Average 170.0 170.0 95.2 100.0 2.0

f. Whatconclusioncanbedrawnfromtheresultsforparts1,2and3?Giveyourreasoning. 2marks

g. Statethechangethestudentshouldmaketotheirexperimentaldesigntoensuretheyachievetheiraim.Justifyyouranswer. 2marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – continued

h. Scientists may use scientific posters to convey their research results to other scientists.

State two different aspects of the electrolysis experiment that the student should include in the discussion section of their scientific poster. 2 marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B–continuedTURN OVER

CONTINUES OVER PAGE


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea


Question 10 (9marks)Climatechangehasbeenidentifiedasathreattotheenvironment.Fossilfuelsarerecognisedasasignificantcontributortotheriseincarbondioxidelevelsintheatmosphere.Thereplacementoffossilfuelsasanenergysourcerepresentsachallengeandhasbeenthefocusofresearchforanumberofyears.However,therearedifferentopinions/viewsaboutthesuitabilityofusingabiofuel,suchasbiodiesel,asareplacementforfossilfuels.Someextractsrepresentingdifferentviewpointsareshownintheboxbelow.

1‘Biofuelsarefuelsthatareproducedfrombiologicalsourcessuchastrees,plantsormicroorganisms.Theyarecarbonneutral,becausetheydonotresultinfossilcarbonbeingreleasedintotheatmosphere.’

2‘AllgoodsolutionsareneededintheenergytransitionrequiredtoachieveEurope’sclimategoals–andsustainablebiofuelsarecriticaltotransportdecarbonisation.’

3‘Manyscientistsviewbiofuelsasinherentlycarbon-neutral:theyassumethecarbondioxide(CO2)plantsabsorbfromtheairastheygrowcompletelyoffsets,or“neutralises,”theCO2emittedwhenfuelsmadefromplantsburn.’4‘…ouranalysisaffirmsthat,asacureforclimatechange,biofuelsare“worsethanthedisease.”’5‘…althoughsomeformsofbioenergycanplayahelpfulrole,dedicatinglandspecificallyforgeneratingbioenergyisunwise.’

Sources:1CarbonNeutralEarth,<www.carbonneutralearth.com/biofuels.php>;2SejersgårdFanø,quotedinErinVoegele, ‘EUreachesdealonREDII,setsnewgoalsforrenewables’,Biodiesel Magazine,15June2018,<www.biodieselmagazine.com>;

3&4JohnDeCicco,‘Biofuelsturnouttobeaclimatemistake–here’swhy’,TheConversation,5October2016, <http://theconversation.com/au>;5AndrewSteerandCraigHanson,‘Biofuelsarenotagreenalternativetofossilfuels’,

The Guardian,30January2015,<www.theguardian.com/au>

a. Usingthechemistrythatyoustudiedthisyearandtheinformationabove,discussthecarbonneutralityandthesustainabilityofusingbiodieselasafuelfortransport. 4marks


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

SECTION B – Question 10 – continuedTURN OVER


do

no

t w

rit

e i

n t

his

ar

ea

do

no

t w

rit

e i

n t

his

ar

ea

b. HazelnutsareatreecropthathasbeengrownformanyyearsinMediterraneanenvironmentsasatreenutforfood.Theyhavebeeninvestigatedasapotentialsustainableandhigh-yieldingfeedstockforbiodiesel.Thespeciesiswell-adaptedtolessproductivesoilandproducesahighamountofverygoodqualityoil.Inadditiontooilyield,hazelnutoilhasauniquefattyacidcomposition(highmonounsaturatedfattyacids,predominantlyoleicacid).

Reference:ThomasMolnar,‘Growinghazelnutsforbiofuelproduction’,eXtension,31January2014, <https://impact.extension.org/>

PetrodieselproducedfromcrudeoilismainlycharacterisedasC12H24.

Comparebiodieselproducedfromhazelnutoiltopetrodieselintermsof:• chemicalstructure• energycontentperkilogram• flowthroughfuellines.

Inyouranswer,youshouldindicatehowthesedifferenceshaveanimpactontheselectionofbiodieselasatransportfuel. 5marks

END OF QUESTION AND ANSWER BOOK

Instructions

This data book is provided for your reference. A question and answer book is provided with this data book.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

CHEMISTRYWritten examination

DATA BOOK

© VICTORIAN CURRICULUM AND ASSESSMENT AUTHORITY 2019

Victorian Certificate of Education 2019

CHEMISTRY DATA BOOK 2

Table of contents Page

1. Periodic table of the elements 3

2. Electrochemical series 4

3. Chemical relationships 5

4. Physical constants and standard values 5

5. Unit conversions 6

6. Metric(includingSI)prefixes 6

7. Acid-base indicators 6

8. Representations of organic molecules 7

9. Formulas of some fatty acids 7

10. Formulas of some biomolecules 8–9

11. Heats of combustion of common fuels 10

12. Heats of combustion of common blended fuels 10

13. Energy content of food groups 10

14. Characteristic ranges for infra-red absorption 11

15. 13C NMR data 11

16. 1H NMR data 12–13

17. 2-aminoacids(α-aminoacids) 14–15

3 CHEMISTRY DATA BOOK

TURN OVER

1. P

erio

dic t

able

of t

he el

emen

ts

1 H

1.0

hydr

ogen

2 He

4.0

heliu

m

3 Li

6.9

lithi

um

4 Be

9.0

bery

llium

5 B

10.8

bo

ron

6 C

12.0

ca

rbon

7 N

14.0

ni

troge

n

8 O

16.0

oxygen

9 F 19.0

fluorine

10

Ne

20.2

ne

on

11

Na

23.0

so

dium

12

Mg

24.3

m

agne

sium

13

Al

27.0

al

umin

ium

14

Si

28.1

si

licon

15

P 31.0

ph

osph

orus

16

S 32.1

su

lfur

17

Cl

35.5

ch

lorin

e

18

Ar

39.9

ar

gon

19

K

39.1

po

tass

ium

20

Ca

40.1

ca

lciu

m

21

Sc

45.0

sc

andi

um

22

Ti

47.9

tit

aniu

m

23

V

50.9

va

nadi

um

24

Cr

52.0

ch

rom

ium

25

Mn

54.9

m

anga

nese

26

Fe

55.8

iro

n

27

Co

58.9

co

balt

28

Ni

58.7

ni

ckel

29

Cu

63.5

co

pper

30

Zn

65.4

zi

nc

31

Ga

69.7

ga

llium

32

Ge

72.6

ge

rman

ium

33

As

74.9

ar

seni

c

34

Se

79.0

se

leni

um

35

Br

79.9

br

omin

e

36

Kr

83.8

kr

ypto

n

37

Rb

85.5

ru

bidi

um

38

Sr

87.6

st

ront

ium

39

Y

88.9

yt

trium

40

Zr

91.2

zi

rcon

ium

41

Nb

92.9

ni

obiu

m

42

Mo

96.0

m

olyb

denu

m

43

Tc

(98)

te

chne

tium

44

Ru

101.

1 ru

then

ium

45

Rh

102.

9 rh

odiu

m

46

Pd

106.

4 pa

lladi

um

47

Ag

107.

9 si

lver

48

Cd

112.

4 ca

dmiu

m

49

In

114.

8 in

dium

50

Sn

118.

7 tin

51

Sb

121.

8 an

timon

y

52

Te

127.

6 te

lluriu

m

53

I 12

6.9

iodi

ne

54

Xe

131.

3 xenon

55

Cs

132.

9 ca

esiu

m

56

Ba

137.

3 ba

rium

57–7

1 la

ntha

noid

s

72

Hf

178.

5 ha

fniu

m

73

Ta

180.

9 ta

ntal

um

74

W

183.

8 tu

ngst

en

75

Re

186.

2 rh

eniu

m

76

Os

190.

2 os

miu

m

77

Ir

192.

2 iri

dium

78

Pt

195.

1 pl

atin

um

79

Au

197.

0 go

ld

80

Hg

200.

6 m

ercu

ry

81

Tl

204.

4 th

alliu

m

82

Pb

207.

2 le

ad

83

Bi

209.

0 bi

smut

h

84

Po

(210

) po

loni

um

85

At

(210

) as

tatin

e

86

Rn

(222

) ra

don

87

Fr

(223

) fr

anci

um

88

Ra

(226

) ra

dium

89–1

03

actin

oids

104

Rf

(261

) ru

ther

ford

ium

105

Db

(262

) du

bniu

m

106

Sg

(266

) se

abor

gium

107

Bh

(264

) bo

hriu

m

108

Hs

(267

) ha

ssiu

m

109

Mt

(268

) m

eitn

eriu

m

110

Ds

(271

) da

rmst

adtiu

m

111

Rg

(272

) ro

entg

eniu

m

112

Cn

(285

) co

pern

iciu

m

113

Nh

(280

) ni

honi

um

114

Fl

(289

) flerovium

115

Mc

(289

) m

osco

vium

116

Lv

(292

) liv

erm

oriu

m

117

Ts

(294

) te

nnes

sine

118

Og

(294

) og

anes

son

57

La

138.

9 la

ntha

num

58

Ce

140.

1 ce

rium

59

Pr

140.

9 pr

aseo

dym

ium

60

Nd

144.

2 ne

odym

ium

61

Pm

(145

) pr

omet

hium

62

Sm

150.

4 sa

mar

ium

63

Eu

152.

0 eu

ropi

um

64

Gd

157.

3 ga

dolin

ium

65

Tb

158.

9 te

rbiu

m

66

Dy

162.

5 dy

spro

sium

67

Ho

164.

9 ho

lmiu

m

68

Er

167.

3 er

bium

69

Tm

16

8.9

thul

ium

70

Yb

173.

1 yt

terb

ium

71

Lu

175.

0 lu

tetiu

m

89

Ac

(227

) ac

tiniu

m

90

Th

232.

0 th

oriu

m

91

Pa

231.

0 pr

otac

tiniu

m

92

U

238.

0 ur

aniu

m

93

Np

(237

) ne

ptun

ium

94

Pu

(244

) pl

uton

ium

95

Am

(2

43)

amer

iciu

m

96

Cm

(2

47)

curiu

m

97

Bk

(247

) be

rkel

ium

98

Cf

(251

) ca

lifor

nium

99

Es

(252

) ei

nste

iniu

m

100

Fm

(257

) fe

rmiu

m

101

Md

(258

) m

ende

levi

um

102

No

(259

) no

beliu

m

103

Lr

(262

) la

wre

nciu

m

The

valu

e in

bra

cket

s ind

icat

es th

e m

ass n

umbe

r of t

he lo

nges

t-liv

ed is

otop

e.

79

Au

197.

0 go

ld

atom

ic n

umbe

r

rela

tive

atom

ic m

ass

sym

bol o

f ele

men

t

nam

e of

ele

men

t


2. Electrochemical series

Reaction Standard electrode potential (E0) in volts at 25 °C

F2(g) + 2e– ⇌ 2F–(aq) +2.87

H2O2(aq) + 2H+(aq) + 2e– ⇌ 2H2O(l) +1.77

Au+(aq) + e– ⇌ Au(s) +1.68

Cl2(g) + 2e– ⇌ 2Cl–(aq) +1.36

O2(g) + 4H+(aq) + 4e– ⇌ 2H2O(1) +1.23

Br2(l) + 2e– ⇌ 2Br–(aq) +1.09

Ag+(aq) + e– ⇌ Ag(s) +0.80

Fe3+(aq) + e– ⇌ Fe2+(aq) +0.77

O2(g) + 2H+(aq) + 2e– ⇌ H2O2(aq) +0.68

I2(s) + 2e– ⇌ 2I–(aq) +0.54

O2(g) + 2H2O(l) + 4e– ⇌ 4OH–(aq) +0.40

Cu2+(aq) + 2e– ⇌ Cu(s) +0.34

Sn4+(aq) + 2e– ⇌ Sn2+(aq) +0.15

S(s) + 2H+(aq) + 2e– ⇌ H2S(g) +0.14

2H+(aq) + 2e– ⇌ H2(g) 0.00

Pb2+(aq) + 2e– ⇌ Pb(s) –0.13

Sn2+(aq) + 2e– ⇌ Sn(s) –0.14

Ni2+(aq) + 2e– ⇌ Ni(s) –0.25

Co2+(aq) + 2e– ⇌ Co(s) –0.28

Cd2+(aq) + 2e– ⇌ Cd(s) –0.40

Fe2+(aq) + 2e– ⇌ Fe(s) –0.44

Zn2+(aq) + 2e– ⇌ Zn(s) –0.76

2H2O(l) + 2e– ⇌ H2(g) + 2OH–(aq) –0.83

Mn2+(aq) + 2e– ⇌ Mn(s) –1.18

Al3+(aq) + 3e– ⇌ Al(s) –1.66

Mg2+(aq) + 2e– ⇌ Mg(s) –2.37

Na+(aq) + e– ⇌ Na(s) –2.71

Ca2+(aq) + 2e– ⇌ Ca(s) –2.87

K+(aq) + e– ⇌ K(s) –2.93

Li+(aq) + e– ⇌ Li(s) –3.04


TURN OVER

3. Chemical relationships

Name Formula

number of moles of a substance n mM

n cV n VVm

= = =; ;

universal gas equation pV = nRT

calibration factor (CF) for bomb calorimetry CF = VItT∆

heat energy released in the combustion of a fuel q = mc∆T

enthalpy of combustion ∆H qn

=

electric charge Q = It

number of moles of electrons n e QF

( )− =

% atom economymolar mass of desired product

molar mass of all reactants×

10001

% yieldactual yield

theoretical yield×

1001

4. Physical constants and standard values

Name Symbol Value

Avogadro constant NA or L 6.02 × 1023 mol–1

charge on one electron (elementary charge) e –1.60 × 10–19 C

Faraday constant F 96 500 C mol–1

molar gas constant R 8.31 J mol–1 K–1

molar volume of an ideal gas at SLC (25 °C and 100 kPa)

Vm 24.8 L mol–1

specificheatcapacityofwater c 4.18 kJ kg–1 K–1 or 4.18 J g–1 K–1

density of water at 25 °C d 997 kg m–3 or 0.997 g mL–1


5. Unit conversions

Measured value Conversion

0 °C 273 K

100 kPa 750 mm Hg or 0.987 atm

1 litre (L) 1 dm3 or 1 × 10–3 m3 or 1 × 103 cm3 or 1 × 103 mL

6. Metric (including SI) prefixes

Metric (including SI)

prefixes

Scientific notation Multiplying factor

giga (G) 109 1 000 000 000

mega (M) 106 1 000 000

kilo (k) 103 1000

deci (d) 10–1 0.1

centi (c) 10–2 0.01

milli (m) 10–3 0.001

micro (μ) 10–6 0.000001

nano (n) 10–9 0.000000001

pico (p) 10–12 0.000000000001

7. Acid-base indicators

Name pH range Colour change from lower pH to higher pH in range

thymol blue (1st change) 1.2–2.8 red → yellow

methyl orange 3.1– 4.4 red → yellow

bromophenol blue 3.0– 4.6 yellow → blue

methyl red 4.4– 6.2 red → yellow

bromothymol blue 6.0–7.6 yellow → blue

phenol red 6.8–8.4 yellow → red

thymol blue (2nd change) 8.0–9.6 yellow → blue

phenolphthalein 8.3–10.0 colourless → pink


TURN OVER

8. Representations of organic moleculesThefollowingtableshowsdifferentrepresentationsoforganicmolecules,usingbutanoicacidasanexample.

Formula Representation

molecular formula C4H8O2

structural formula

C

H

H

C

H

H

C

H

H

C

HO

O

H

semi-structural (condensed) formula CH3CH2CH2COOH or CH3(CH2)2COOH

skeletal structure O

OH

9. Formulas of some fatty acids

Name Formula Semi-structural formula

lauric C11H23COOH CH3(CH2)10COOH

myristic C13H27COOH CH3(CH2)12COOH

palmitic C15H31COOH CH3(CH2)14COOH

palmitoleic C15H29COOH CH3(CH2)4CH2CH=CHCH2 (CH2)5CH2COOH

stearic C17H35COOH CH3(CH2)16COOH

oleic C17H33COOH CH3(CH2)7CH=CH(CH2)7COOH

linoleic C17H31COOH CH3(CH2)4(CH=CHCH2)2(CH2)6COOH

linolenic C17H29COOH CH3CH2(CH=CHCH2)3(CH2)6COOH

arachidic C19H39COOH CH3(CH2)17CH2COOH

arachidonic C19H31COOH CH3(CH2)4(CH=CHCH2)3CH=CH(CH2)3COOH


10. Formulas of some biomolecules

C

C

C

H

H

OH

OH

OH

H

H

H

glycerol

sucrose

OH OH

OH OHHO

O O

O

CH2OH CH2OH

CH2OH

vitamin C (ascorbic acid)

O

OH

O

HO

CH

OH

CH2

HO

vitamin D2 (ergocalciferol)HO

CHCH

CHCH3

CH2

H3C CH3

CH3

CHCH

CHCH3

CH

HO

β-fructose

OH

OH

OCH2OH

CH2OH

vitamin D3 (cholecalciferol)HO

CHCH

CH3

CH2

CHH3C CH3CH2

CH2

CHCH3

CH2

α-glucose

OH

OHHO

O

OH

CH2OH

α-lactoseOH

OH

HO O OCH2OH

OH

OHOH

OCH2OH


TURN OVER

OH

OH

O

O O

CH2OH

OH

OH

O

O

CH2OH

OH

OH

O

O

CH2

OH

OH

O

O

CH2OH

amylopectin (starch)

O

OH

OH

O

O O

CH2OH

OH

OH

O

O

CH2OH

OH

OH

O

O

CH2OH

amylose (starch)

n

O

HO

O

O

O

N CH3

aspartame

H

H2N OH

OH

n

cellulose

OH

OH

O

O

O

O

CH2OH

CH2OH


11. Heats of combustion of common fuelsThe heats of combustion in the following table are calculated at SLC (25 °C and 100 kPa) with combustion products being CO2 and H2O.Heatofcombustionmaybedefinedastheheatenergyreleasedwhenaspecifiedamountofasubstanceburnscompletelyinoxygenandis,therefore,reportedasapositivevalue,indicating a magnitude. Enthalpy of combustion, ∆H, for the substances in this table would be reported as negativevalues,indicatingtheexothermicnatureofthecombustionreaction.

Fuel Formula State Heat of combustion (kJ g–1)

Molar heat of combustion (kJ mol–1)

hydrogen H2 gas 141 282

methane CH4 gas 55.6 890

ethane C2H6 gas 51.9 1560

propane C3H8 gas 50.5 2220

butane C4H10 gas 49.7 2880

octane C8H18 liquid 47.9 5460

ethyne (acetylene) C2H2 gas 49.9 1300

methanol CH3OH liquid 22.7 726

ethanol C2H5OH liquid 29.6 1360

12. Heats of combustion of common blended fuelsBlendedfuelsaremixturesofcompoundswithdifferentmixtureratiosand,hence,determinationofagenericmolar enthalpy of combustion is not realistic. The values provided in the following table are typical values for heats of combustion at SLC (25 °C and 100 kPa) with combustion products being CO2 and H2O. Values for heats of combustion will vary depending on the source and composition of the fuel.

Fuel State Heat of combustion (kJ g–1)

kerosene liquid 46.2

diesel liquid 45.0

natural gas gas 54.0

13. Energy content of food groups

Food Heat of combustion (kJ g–1)

fats and oils 37

protein 17

carbohydrate 16


TURN OVER

14. Characteristic ranges for infra-red absorption

Bond Wave number (cm–1)

Bond Wave number (cm–1)

C–Cl (chloroalkanes) 600–800 C=O (ketones) 1680–1850

C–O (alcohols, esters, ethers) 1050–1410 C=O (esters) 1720–1840

C=C (alkenes) 1620–1680 C–H (alkanes, alkenes, arenes) 2850–3090

C=O (amides) 1630–1680 O–H (acids) 2500–3500

C=O (aldehydes) 1660–1745 O–H (alcohols) 3200–3600

C=O (acids) 1680–1740 N–H (amines and amides) 3300–3500

15. 13C NMR dataTypical 13C shift values relative to TMS = 0These can differ slightly in different solvents.

Type of carbon Chemical shift (ppm)

R–CH3 8–25

R–CH2–R 20– 45

R3–CH 40–60

R4–C 36– 45

R–CH2–X 15–80

R3C–NH2, R3C–NR 35–70

R–CH2–OH 50–90

RC CR 75–95

R2C=CR2 110–150

RCOOH 160–185

OR

ROC

165–175

OR

HC

190–200

R2C=O 205–220


16. 1H NMR dataTypical proton shift values relative to TMS = 0These can differ slightly in different solvents. The shift refers to the proton environment that is indicated in bold letters in the formula.

Type of proton Chemical shift (ppm)

R–CH3 0.9–1.0

R–CH2–R 1.3–1.4

RCH=CH–CH3 1.6–1.9

R3–CH 1.5

or CH3

ORC

OCH3

NHR

CO

2.0

CH3R

C

O

2.1–2.7

R–CH2–X (X = F, Cl, Br or I) 3.0– 4.5

R–CH2–OH, R2–CH–OH 3.3– 4.5

R

NHCH2R

CO

3.2

R—O—CH3 or R—O—CH2R 3.3–3.7

O C

O

CH32.3

R

OCH2R

CO

3.7– 4.8

R–O–H 1–6(varies considerably under different conditions)

R–NH2 1–5

RHC CHR 4.5–7.0

OH 4.0–12.0


TURN OVER

Type of proton Chemical shift (ppm)

H 6.9–9.0

R

NHCH2R

CO

8.1

R

H

CO

9.4 –10.0

RH

CO

O9.0–13.0


17. 2-amino acids (α-amino acids)Thetablebelowprovidessimplifiedstructurestoenablethedrawingofzwitterions,theidentificationofproducts of protein hydrolysis and the drawing of structures involving condensation polymerisation of amino acid monomers.

Name Symbol Structure

alanine Ala

H2N CH COOH

CH3

arginine Arg

H2N CH COOH

CH2 CH2 CH2 NH

NH

C NH2

asparagine Asn

H2N CH COOH

CH2

O

C NH2

aspartic acid Asp

H2N CH COOH

CH2 COOH

cysteine Cys

H2N CH COOH

CH2 SH

glutamic acid Glu

H2N CH COOH

CH2 CH2 COOH

glutamine Gln

H2N CH COOH

CH2 CH2

O

C NH2

glycine Gly H2N CH2 COOH

histidine His

H2N CH COOH

CH2 NH

N

isoleucine Ile

H2N CH COOH

CH3 CH CH2 CH3


END OF DATA BOOK

Name Symbol Structure

leucine Leu

H2N CH COOH

CH2

CH3 CH CH3

lysine Lys

H2N CH COOH

CH2 CH2 CH2 CH2 NH2

methionine Met

H2N CH COOH

CH2 CH2 S CH3

phenylalanine Phe

H2N CH

CH2

COOH

proline Pro COOH

HN

serine Ser

H2N CH COOH

CH2 OH

threonine Thr

H2N CH COOH

CH3 CH OH

tryptophan Trp

H2N CH

CH2

COOH

HN

tyrosine Tyr OH

H2N CH

CH2

COOH

valine Val

H2N CH COOH

CH3 CH CH3

Documents

2019 Chemistry Written examination