2021 Chemistry-nht Written examination

CHEMISTRYWritten examination

Tuesday 1 June 2021 Reading time: 10.00 am to 10.15 am (15 minutes) Writing time: 10.15 am to 12.45 pm (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• Questionandanswerbookof39pages• 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.

©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2021

SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2021

STUDENT NUMBER

Letter

2021CHEMISTRYEXAM(NHT) 2

SECTION A – continued

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Question 1 Thefollowingtableshowsanumberoffuelsandacommonmethodofproductionorsourceforeachfuel.

Fuel Common method of production or source

liquefiedpetroleumgas(LPG) extractedduringproductionofnaturalgas

kerosene fractionaldistillationfromcrudeoil

biodiesel convertedfromfat

ethanol fermentationofcorn

hydrogen electrolysisofwater

naturalgas extractedfromshale

methane chemicalbreakdownoforganicmaterialbyanaerobicbacteria

Basedontheinformationprovidedinthetableabove,whichofthefollowinglistsonlyfossilfuels?A. hydrogen,kerosene,LPGB. kerosene,LPG,naturalgasC. ethanol,methane,naturalgasD. biodiesel,hydrogen,methane

Question 2 Calciummetalcanbeobtainedfromtheelectrolysisofmoltencalciumchloride.Duringthisprocess,calciumionsflowtotheA. anodeandarereducedtocalciummetal.B. anodeandareoxidisedtocalciummetal.C. cathodeandarereducedtocalciummetal.D. cathodeandareoxidisedtocalciummetal.

SECTION A – Multiple-choice questions

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

3 2021CHEMISTRYEXAM(NHT)

SECTION A – continuedTURN OVER

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Question 3 Whichoneofthefollowingstatementsaboutrechargeablebatteriesismostcorrect?A. Sidereactionsattheelectrodesreducebatterylife.B. Duringdischargethebatteryoperatesasanelectrolyticcell.C. Batterylifeisindirectproportiontothetemperaturewhenthebatteryisinuse.D. Duringdischargethecellvoltageishigherthanthevoltagebeingusedtorechargethecell.

Question 4 Wheneggwhitesarebeaten,changesintheirappearanceoccur.Theeggwhiteswillchangefromaclearliquidtoafirm,whitepeak.Whichproteinstructure(s)isalteredwhenthischangeoccurs?A. theprimary,secondaryandtertiarystructuresB. thesecondaryandtertiarystructuresC. theprimarystructureonlyD. thetertiarystructureonly

Question 5Asingle10gpieceofironmetaliscompletelysubmergedin50mLof0.2Mnitricacid,HNO3 ,containedina100mLbeaker.Theexperimentisperformedatstandardlaboratoryconditions(SLC).Thereactionthatoccursis

Fe(s)+2HNO3(aq)→Fe(NO3)2(aq)+H2(g)

TherateofthereactionwouldmostlikelyincreaseiftheA. reactionwasperformedinafumecupboardtoremovethehydrogengasformed.B. singlepieceofironmetalwasreplacedwith70pieces(0.1geach)ofironmetal.C. volumeoftheacidwasincreasedbyadding20mLofwater.D. experimentwasperformedat10°C.

Question 6 WhichoneofthefollowingformulasbestrepresentsglycineinasolutionatpH4?A. +NH3CH2COOHB. NH2CH2COOHC. +NH3CH2COO

– D. NH2CH2COO

−

Question 7 Ammoniumnitrate,NH4NO3 ,canbeusedinchemicalcoldpacksthatareoftenfoundinfirst-aidkits.Acalorimeterwaselectricallycalibratedusing100mLofpurewaterandwasthenusedtodeterminethemolarheatofsolutionofNH4NO3.Ifthewaterwasreplacedpriortodeterminationofthemolarheatofsolutionand,insteadof100mL,only 90mLwasaddedtothecalorimeter,themolarheatofsolutiondeterminedwouldbeA. lowerduetothetemperaturechangebeingsmaller.B. lowerduetothetemperaturechangebeinggreater.C. higherduetothetemperaturechangebeingsmaller.D. higherduetothetemperaturechangebeinggreater.



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Question 8 WhichoneofthefollowingfuelsisexpectedtohavethehighestviscosityatSLC?A. petrodieselB. bioethanolC. biodieselD. petrol

Use the following information to answer Questions 9 and 10.Achemististitratingavolumeofanunknownmonoproticorganicacidagainst50mLof0.30Msodiumhydroxide,NaOH,usingmethylredasanindicator.Thechemistobservesthefirstpermanentcolourchangeat23.65mL.

Question 9 AvalidconclusionthatcanbedrawnfromthisinformationisthatA. theconcentrationoftheunknowncompoundis0.14M.B. aredoxtitrationontheunknowncompoundwillnotproduceacolourchange.C. usingphenolphthaleinasanindicatorwillproducethesametitre.D. if0.10MNaOHisusedinthetitration,theresultswillbemoreprecise.

Question 10 Ifthetitrationisrepeatedseveraltimes,averagingtheresultswillreducetheA. accuracyoftheresults.B. reliabilityoftheresults.C. effectofrandomerrors.D. effectofsystematicerrors.

Question 11

N C

H H

H

H

HH HC

H

C C O HH

H

WhatistheIUPACsystematicnameforthemoleculeshownabove?A. 3-aminobutan-1-olB. 4-hydroxybutan-2-amineC. 3-methyl-3-aminopropan-1-olD. 3-hydroxy-1-methylpropan-1-amine

Question 12 Whichoneofthefollowingmoleculescanbeoxidisedtoproduceacarboxylicacid?A. propan-2-olB. 1-chlorobutan-1-olC. 2,2-dichloroethanolD. 2-methylpropan-2-ol



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Question 13 Over40countriesaroundtheworlduseE10unleadedfuel,whichconsistsofablendof90%m/moctaneand10%m/methanol.AfulltankofE10unleadedfuelproduces2396MJofenergywhenitundergoescompletecombustionatSLC.ThemassoffuelthatproducesthisamountofenergyisA. 5.0×10–2tonnes.B. 5.2×10–2tonnes.C. 7.6×10–2tonnes.D. 8.1×10–2tonnes.

Question 14 Astudentinvestigatedtherateofreactionbetweendilutehydrochloricacid,HCl,andcalciumcarbonate,CaCO3 .ThestudentperformedtwoexperimentsusingtwopiecesofCaCO3ofdifferentshapes.Ineachexperiment,Experiment1andExperiment2,0.34gofCaCO3and12.0mLof0.50MHClwasusedandthevolumeofgasproducedatSLCwasmeasuredat10sintervals.Thefollowingreactiontakesplace.

CaCO3(s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2(g)

ThemolarmassofCaCO3 is100.1gmol−1.

Thestudentplottedtheresultsandproducedthegraphshownbelow.

90

80

70

60

50

40

30

20

10

00 20 40 60 80 100

time (s)120 140 160 180 200

Volume of CO2 evolved over time

volume ofCO2 evolved

(mL)

KeyExperiment 1Experiment 2

At160sthetwolinesmeet.ThisisbecauseA. bothreactionshavereachedequilibrium.B. theCaCO3hascompletelyreactedandthereissomeacidremaining.C. theacidhascompletelyreactedandthereissomeCaCO3remaining.D. bothreactionshavestoppedbecauseallreactantshavebeenconsumed.



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Question 15A20.00mLsampleofvinegarisdilutedinavolumetricflask.Thevolumetricflaskisthenfilleduptothelinemarkingitsdesignatedvolume.A20.00mLaliquotofthedilutedsampleofvinegaristitratedagainsta0.102Msolutionofpotassiumhydroxide,KOH,usingaphenolphthaleinindicator.Iftheundilutedsampleofvinegarhasaconcentrationof3.16%m/vaceticacid,CH3COOH,whichvolumetricflaskshouldbeselectedtobeabletodilutetheoriginalsampleofvinegarandobtaintitresofabout20mL?A. 100mLvolumetricflaskB. 200mLvolumetricflaskC. 250mLvolumetricflaskD. 1000mLvolumetricflask

Question 16 Carbonmonoxide,CO,andoxygen,O2,dissociatefromhaemoglobin,representedbyHb,inthebloodaccordingtotworeactions.

Reaction1 Hb(O2)4 ⇌Hb+4O2 K1

Reaction2 Hb(CO)4 ⇌Hb+4CO K2

Whichoneofthefollowingstatementsistrue?A. K2ismuchgreaterthanK1.B. O2bindsmorereadilytoHbthanCO.C. IncreasedlevelsofCOinthebloodfavourtheforwardreactionforReaction1.D. Breathing100%O2increasestheamountoffreeHbinapersonexposedtoCO.



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Use the following information to answer Questions 17 and 18.Thefollowingdiagramsshowtwogalvaniccells,Galvaniccell1andGalvaniccell2,withplatinum,Pt,electrodesand1.0Mconcentrationsofsaltsolutions.BothcellsweresetupatSLC.Avoltagewasproducedineachcell.Thedirectionofmovementoftheionsinthesaltbridgeisindicatedineachdiagram.

V

A

salt bridgecations anions

Pt(s) Pt(s) Pt(s) Pt(s)

IO3–(aq)/I2(aq) I2(aq)/I–(aq)

V

A

salt bridgeanions cations

Sn4+(aq)/Sn2+(aq) I2(aq)/I–(aq)

Galvanic cell 1 Galvanic cell 2

Question 17 Whichoneofthefollowingstatementsistrue?A. TheweakestreducingagentisSn2+.B. ThestrongestoxidisingagentisI –.C. ThestrongestoxidisingagentisIO3

–.D. TheweakestreducingagentisI –.

Question 18 Acorrectlybalancedhalf-equationoccurringinGalvaniccell1isA. IO3

–(aq)+6H+(aq)+6e– → I–(aq)+3H2O(l)B. I–(aq)+3H2O

+(l)→IO3–(aq)+6H+(aq)+6e–

C. I2(aq)+6H2O(l)→2IO3–(aq)+12H+(aq)+10e–

D. 2IO3–(aq)+12H+(aq)+10e– → I2(aq)+6H2O(l)

Question 19 ThenumberofunbranchedestersthathaveamolecularformulaofC4H8O2isA. 2B. 3C. 4D. 5



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Question 20 ThevalueoftheequilibriumconstantKcat1000Kforthedissociationofiodinegas,I2,toiodineatoms,I,inasealedcontaineris3.76×10–3.Theequationisgivenbelow.

I2(g)⇌2I(g)

Whichoneofthefollowingstatementsappliestothissystemwhenithasreachedequilibriumat1000K?A. Addinganinertgaschangestheequilibriumconstant.B. ThedissociationofI2gastoIatomswilloccurcontinuously.C. Theequilibriumconstantisdependentonthepressureinthecontainer.D. Therateoftheforwardreactionisslowerthantherateofthereversereaction.

Question 21 Twocompounds,hexan-1-olanddi-isopropylamine,havesimilarmolarmasses,yettheyhavedifferentboilingpoints.Thisinformationissummarisedinthetablebelow.

Compound Molar mass (g mol–1) Boiling point (°C)

hexan-1-ol

CH3CH2CH2CH2CH2CH2 OH

102 157

di-isopropylamine

CH3

CH

CH3

CHH3C NH CH3

101 83

Whichoneofthefollowingisthemainreasonforthedifferenceinboilingpoint?A. thenumberofcarbonatomsineachcompoundB. thestrengthofthedispersionforcesofeachcompoundC. thedifferentchemicalreactivitiesofeachcompoundD. theN–HbondislesspolarintheaminethantheO–Hbondinhexan-1-ol



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Use the following information to answer Questions 22 and 23.Thediagrambelowshowstheapparatusforabombcalorimeter.

thermometer

insulatedcontainer

sealed vessel 0.720 g ethanol

stirrer

ignition wire

500 g water

oxygen (excess)

Question 22 Thebombcalorimetercontaining500gofwaterwaschemicallycalibratedbycombusting0.720gofethanolwithanexcessofoxygen.Theincreaseintemperaturewasfoundtobe22.0°C.Whichoneofthefollowingbestexplainstheseresults?A. Thestirrerwasnotworking.B. Thecalorimeteractuallycontained450gofwater.C. Thetemperatureinthecalorimeterwasstillrisingafterthefinaltemperaturewasnoted.D. Someoftheethanolevaporatedafteritwasweighed,butbeforeitwasaddedtothecalorimeter.

Question 23 Thebombcalorimeterwasrecalibratedusingbenzoicacidandwasfoundtohaveacalibrationfactorof 1.67kJ°C–1.If1.5gofafoodcontaining63%m/mfatand37%m/mproteinwascombustedinthebombcalorimeter, byhowmuchwouldthetemperaturebeexpectedtorise?A. 33°CB. 27°CC. 17°CD. 15°C



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Question 24 Belowisanenergyprofilediagramforanuncatalysedreversiblereaction.

4035302520151050

energy (kJ mol–1)

Y + 2Z

3X + W

Acatalystwasaddedtothesystem,causingtherateoftheforwardandreversereactionstoincrease.Whichoneofthefollowingcouldbetrueforthecatalysedreaction?A. Theactivationenergytoproduce1molofWis29kJ.B. Theactivationenergytoproduce1molofZis12kJ.C. Theactivationenergytoproduce0.5molofXis5kJ.D. Theactivationenergytoproduce9molofYis120kJ.

Question 25

CH3COOH + + Η2ΟReactant X Product Y

WhichofthefollowingidentifiesReactantXandProductYinthecondensationreactionshownabove?

Reactant X Product Y

A. CH3CH2OH CH3CHOHCH2CH3

B. CH3CH2NH2 CH3CH2CONHCH3

C. CH3CH3 CH3COCH2CH3

D. CH3NH2 CH3CONHCH3

Question 26 Considerallofthecomponentsinvolvedintheproductionofbiofuels.Themost accuratestatementaboutallbiofuelsisthattheyA. arenotsustainablesourcesofenergy.B. producegreenhousegasemissionswhenburnt.C. producethesameamountofenergyperunitofmassasfossilfuels.D. releaselesscarbondioxideperunitofenergyproducedthanfossilfuels.



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Question 27 Ahigh-performanceliquidchromatography(HPLC)columnhasanon-polarstationaryphaseandapolarsolventasthemobilephase.Whichoneofthefollowingsubstanceswouldhavethelowestretentiontime?A. tetrachloromethaneB. chloromethaneC. bromomethaneD. hexane

Use the following information to answer Questions 28 and 29.Scientistshavedevelopedanewtypeofhydrogenfuelcellforuseonalargescaleinfactoriesandmanufacturingplants,asshowninthediagrambelow.Thefuelcelloperatesat600°C.

electron flowe–

e–e–

O2

CO2

CO2

CO2

CO32–CO2

H2O

O2H2

H2O

electrolyte

anode cathode

e– e–

CO2

Question 28 Theequationforthehalf-cellreactionoccurringatthepositiveelectrodeinthediagramaboveisA. 2CO2+4H2O+4e

– →O2+2CO32–+8H+

B. H2+CO32– →CO2+H2O+2e

–

C. H2O+CO2+2e– →CO3

2–+H2D. O2+2CO2+4e

– →2CO32–

Question 29 Whichoneofthefollowingstatementsisaccurateforthistypeofhydrogenfuelcell?A. Heatisaby-productofthishydrogenfuelcell.B. O2isoxidisedtoproduceCO2.C. Theenthalpyofthereactantsislessthantheenthalpyoftheproducts.D. CO2isreleasedintotheenvironment.


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END OF SECTION A

Question 30 TheglycaemicindexofafoodcanbeA. determinedusingabombcalorimeter.B. calculatediftheamountofglucosepresentinthefoodisknown.C. determinedexperimentallyusinghumansubjectswithvariedratesofmetabolism.D. determinedinthelaboratorybyhydrolysingafoodsampleandmeasuringtheyieldofglucoseafter

twohours.


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TURN OVER

CONTINUES OVER PAGE


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SECTION B – Question 1–continued

SECTION B

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

Question 1 (9marks) Macromoleculesperformdifferentfunctionsinthehumanbody.

a. Whatisthenameofthemacromoleculethatisformedfromglucoseandisusedtostoreenergyinthehumanbody? 1mark

b. i. Whatisthefunctionofapeptidebondinthestructureofaprotein? 1mark

ii. Eachproteinisunique.

Describewhatmakeseachproteinunique. 1mark

c. DNApolymeraseisanexampleofaproteinthathasaquaternarystructure.

Describethequaternarystructureofaprotein. 2marks


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SECTION B – continuedTURN OVER

d. Enzymesarespecifictypesofproteins.

Explainhowtheinducedfitmodeldescribestheactionofanenzymeduringareaction.Youmayincludediagramsinyouranswer. 2marks

e. Someenzymesrequireacoenzymeinordertoperformtheirfunction.

Identifytwofunctionsofacoenzymeduringareaction. 2marks


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Question 2 (7marks)

liquid LPG

gaseous LPG

Liquefiedpetroleumgas(LPG)isfoundinthegasbottlesusedforbarbecuesandoutdoorheaters.LPGcanbepropane,butaneoramixtureofboth.LPGthatisuseddomesticallyinAustraliaistypicallypropane.Itissuppliedin17.00Lcylindersthatarefilledtoamassof8.50kg.LPGisstoredunderpressureandexistsinbothliquidandgasforminthecylinder.ThepressureinthecylinderwillremainthesamefromwhenthecylinderisfulluntilthelastoftheliquidLPGisvaporisedtogas.Itisimportanttohaveadequateventilationwheneverpropaneisburntinanenclosedarea.

a. Onacoldandrainyday,apropaneLPGheaterwasusedtoheatasmall,enclosed,outdoorarea.

Writeabalancedchemicalequationfortheincompletecombustionofpropanegas,wherecarbonmonoxideistheonlycarbonproduct. 1mark


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b. Atatemperatureof27.0°C,thepressureinadomesticpropaneLPGcylinderis883kPa.Thedensityofliquidpropaneis489.3gL–1.

Ifthecylinderisfilledto50%ofitscapacitybyvolumewithliquidpropane,determinethetotalmassofpropane,bothliquidandgas,inkilograms,inthecylinder. 4marks

c. AnLPGcylindercontainingapropaneliquidandgasmixtureismoresuitableforuseincoldweatherthanabutaneliquidandgasmixture.

Explainwhy,intermsofthestructureandpropertiesofthetwomolecules. 2marks


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Question 3 (8marks)ThereactionpathwaybelowrepresentsthesynthesisofCompoundU.

H

H

HC

H

H

H

CC

OH

HC

but-3-en-1-ol

1-chloropropane

Reagent(s)

Compound S Compound T

NH3

Compound U


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a. But-3-en-1-olhasthemolecularformulaC4H8O.

Excludingbut-3-en-1-ol,howmanyotherstereoisomersofthiscompoundexist?Giveyourreasoning. 2marks

b. WhenCompoundSismixedwithasolutionofsodiumcarbonate,Na2CO3,bubblesofgasareobserved.

Writethechemicalformula(s)ofthereagent(s)intheboxprovidedonpage18. 1mark

c. DrawthestructuralformulaofCompoundSintheboxprovidedonpage18. 1mark

d. IdentifythetypeofreactionthatformsCompoundT. 1mark

e. Writethesemi-structuralformulaofCompoundTintheboxprovidedonpage18. 1mark

f. WritetheskeletalformulaofCompoundUintheboxprovidedonpage18. 2marks


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Question 4 (9marks) ChiaisatypeofplantseedthatwasusedbytheAztecsandMayansinMexicoandGuatemalaover5000yearsagoasafoodsourcetoprovideenduranceandenergy.Thisseedhasbeencalleda‘superfood’anditisoneofthelatesthealthtrends,withchiaseedsbeingusedinjuices,smoothies,yoghurtsandsalads.Thetablebelowshowsthenutritioninformationfordriedchiaseeds.

Per 100 g of dried chia seeds

Protein 16.5g

Carbohydrates 42.1g(80%insolubledietaryfibre)

Saturated fat 3.33g

Monounsaturated fat 2.31g

Polyunsaturated fat 23.7g

Trans fat 0.14g

a. Calculatetheamountofenergy,inkilojoules,in100gofdriedchiaseeds,thatcanbeaccessedbythehumanbody. 2marks

b. Amyloseisacarbohydratethatisoneoftheconstituentsofchiaseeds.

Statewhyamylosecontributestochiaseedshavingalowglycaemicindex. 1mark

c. Fatshaveahighenergycontent.

Giveonereasonwhyamoderateintakeoffatsisrequiredinourdiets. 1mark


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d. Thechemicalstructureofafatmoleculefoundinchiaseedsisshownintheincompletehydrolysisequationbelow.

Writethetwomissingchemicalformulasintheboxesprovidedtocompletethehydrolysisequation. 2marks

OCOC17H29

OCOC17H29

OCOC17H29

H

C

C

C

H

H

H

H

+ glycerol +

e. Someunsaturatedfattyacidscanbeclassifiedasomega-3oromega-6fattyacids.

Whatisthedifferencebetweenthesefattyacidsintermsoftheirchemicalstructure? 1mark

f. ChiaseedscontainasmallamountofvitaminC.VitaminCisawater-solublecompoundwhereasvitaminDisafat-solublecompound.

Explainwhythereisadifferenceinthesolubilitiesofthesetwovitaminswithreferencetotheirchemicalstructures. 2marks


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Question 5 (10marks) Platinum,Pt,isapreciousmetalusedincatalyticconvertersincars.OnewayofrecoveringthisPtmaybetomeltscrapcatalyticconverterswithcopper,Cu,andthenelectrolysetheresultantCu–Ptalloy.ThediagrambelowshowsanelectrolysiscellsetuptorecoverPtfromanalloycontaining 99.4%m/mCuand0.6%m/mPt.ThePtisevenlydistributedthroughoutthealloy.

powersupply

CuSO4(aq)

pure Cu Cu–Pt alloy

ThereactionPt2+(aq)+2e– ⇌Pt(s)hasanE0of1.20Vat25°C.

a. Apowersupplyisconnectedacrosstheelectrodes.

LabelthepolarityoftheCu–Ptalloyelectrodeintheboxprovidedonthediagramabove. 1mark

b. WhathappensattheCu–Ptalloyelectrodeasthecurrentisappliedtotheelectrolysiscell?Giveyourreasoning. 2marks

c. Writethehalf-equationthatoccursatthecathode. 1mark


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d. Explainwhyanaqueoussolutionofcopper(II)sulfate,CuSO4,isusedastheelectrolyte. 2marks

e. Calculatehowlong,inhours,acurrentof2.00AwouldneedtobeappliedtorecoverthePtin356.0gofthealloy. 4marks


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Question 6 (9marks) 5.0molofoxygen,O2 ,and10.0molofsulfurdioxide,SO2 ,areinjectedintoa5.0Levacuatedandsealedcontaineratstandardlaboratoryconditions(SLC)andallowedtoachieveequilibrium.Theequationforthisreactionisgivenbelow.

O2(g)+2SO2(g)⇌2SO3(g)

a. Atequilibrium,theconcentrationofO2is0.32M.

Calculatetheequilibriumconstant,Kc. 3marks


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b. Attimet1afterequilibriumhasbeenachieved,thevolumeofthecontainerisexpandedto 10.0Latconstanttemperature.

i. Onthegraphbelow,drawtheconcentrationofO2aftertimet1untilequilibriumis re-established. 2marks

0 t1time elapsed

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

concentrationof O2 (M)

ii. Justifyyouranswertopart b.i.usingLeChatelier’sprinciple. 2marks

iii. Whatistheeffectoftheexpansionofthecontainerontherateoftheforwardreaction?Giveyourreasoningusingcollisiontheory. 2marks


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Question 7 (9marks) Researchershaveinvestigatedgeneratinghydrogen,H2 ,gasforhydrogenfuelcellsbyreactingzinc,Zn,andwater,H2O,inanelectrochemicalcellinserieswithanH2fuelcell.ThediagrambelowrepresentsanalkalineH2fuelcellinserieswithaZn–H2generatorcell.

electrode electrodeelectrode Zn electrode

KOH(aq)

airH2

H2O

H2 fuel cell Zn–H2 generator cell

load

ThereactionsthatoccurateachelectrodeintheZn–H2generatorcellaregivenbelow.

2H2O(l)+2e– →H2(g)+2OH

–(aq)

Zn(s)+2OH–(aq)→ZnO(s)+H2O(l)+2e–

a. WritetheoverallreactionfortheproductionofH2gasintheZn–H2generatorcell. 1mark

b. Writethehalf-equationthatoccursattheanodeofthealkalineH2fuelcell. 1mark

c. Intheboxprovidedinthediagramabove,drawanarrowtoshowthedirectionoftheflowofelectrons. 1mark

d. IntermsofH2gasflowandelectronflow,explainwhyitistheoreticallypossibletoconnecttheH2fuelcellinserieswiththeZn–H2generatorcell. 2marks


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e. ExplainwhytheZn–H2generatorcellmustbewell-sealedtopreventcontactwiththeatmosphereinordertoproduceH2.Includeanyrelevantequationsinyouranswer. 2marks

f. Assumingthesystemis100%efficient,describealloftheenergyconversionsthatoccurin acombinedZn–H2generatorcellandH2fuelcellsystem. 2marks


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SECTION B – continued

THIS PAGE IS BLANK


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SECTION B – Question 8–continuedTURN OVER

Question 8 (9marks) Achemisthasasampleofanunknownhydrocarbon,MoleculeL.ThediagrambelowshowsthemassspectrumofMoleculeL.

Mass spectrum

100

80

60

40

20

00 10 20 30

m/z40 50 60

relativeintensity

Data:NationalInstituteofStandardsandTechnology,NISTChemistryWebBook, <https://webbook.nist.gov/chemistry>

a. i. Whatisthem/zofthebasepeak? 1mark

ii. WhatisthemolecularformulaofMoleculeL? 1mark

iii. Identifythefragmentthatproducesthepeakat41m/z. 1mark

b. DrawthestructuralformulasfortwoisomersofMoleculeL. 2marks


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ThechemistfindsthatMoleculeLreactswithhydrogenbromide,HBr,toformtwoproductsthatareisomers.The13CNMRspectraofthetwoproductsareshownbelow.

Product 1

200 180 160 140 120 100ppm

80 60 40 20 0

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

Product 2

200 180 160 140 120 100ppm

80 60 40 20 0



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c. i. DrawthestructuralformulaofMoleculeL. 1mark

ii. Theinformationforthe1HNMRspectrumofProduct1isshownbelow.

Chemical shift Relative peak area

3.4 2

1.8 2

1.5 2

0.9 3

UsethisinformationtogivetheIUPACsystematicnameforProduct1. 1mark


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d. MoleculeLundergoesahydrationreaction.SpectrumX,SpectrumYandSpectrumZarethespectraforthreedifferentcompounds.

Spectrum X

4000 3000 2000wave number (cm–1)

1500 1000 500

100

50

0

transmittance(%)


Spectrum Y

4000 3000 2000wave number (cm–1)

1500 1000 500

100

50

0

transmittance(%)



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Spectrum Z

4000 3000 2000wave number (cm–1)

1500 1000 500

100

50

0

transmittance(%)


Whichofthespectrashownonpages32and33isconsistentwithaproductofthehydrationreactionforMoleculeL?Youranswershouldmakereferencetotheinformationinthespectra. 2marks


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Question 9 (12marks)Foranexperimentalextendedresearchinvestigation,agroupofstudentsperformedexperimentsoverthreedaystoinvestigatethestabilityofascorbicacid,C6H8O6,infreshlypreparedpineapplejuice.Partofthereportsubmittedbyoneofthestudentsisshownbelow.

ResearchTheconcentrationofC6H8O6inpineapplejuiceisdeterminedbyperformingatitrationwithastandardisediodine,I2 ,solution.TheC6H8O6reactswithI2toformdehydroascorbicacid,C6H6O6,andiodideions,I –.Thisreactionisrepresentedbythebalancedequation

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

AimToinvestigatetheeffectoftemperatureonthestabilityofC6H8O6infreshlypreparedpineapplejuiceoverthreedays

MethodPart A – Preparation of fresh pineapple juice1. Cutawholepineappleinto2cmpieces.2. Blendthepineapplepiecesusingafoodprocessorfortwominutesandfilterthemixturethrough

amicrofibrecloth.

Part B – Determination of the concentration of C6H8O6 at the beginning of the investigation1. Accuratelyweigh5.00gofthefilteredpineapplejuiceinaclean100mLconicalflask.2. Add25mLofdeionisedwaterand10dropsof0.5%starchindicatorsolutiontotheconicalflask.3. Shaketheflasktoensurethatthecontentsaremixed.4. Fillacleanburettewitha2.50×10–4MsolutionofI2 .Recordtheinitialvolume.5. Carefullytitratethepineapplejuicesolutionwiththeiodinesolutionuntilapermanentbluecolour

isobserved.Recordthefinalvolumeandcalculatethetitre.6. Repeatsteps1–5untilconcordanttitresareobtained.

Part C – Set-up of pineapple juice samples, days 1–31. Wraptheoutsideofnineclean100mLconicalflaskswithaluminiumfoil.2. Labelthreeoftheconicalflasks‘5°C’,labelanotherthreeoftheconicalflasks‘15°C’andlabel

theremainingthreeconicalflasks‘30°C’.3. Accuratelyweigh40.00goffilteredpineapplejuiceintoeachofthenineconicalflasks.4. Sealeachconicalflaskwithsiliconefilm.5. Placeeachlabelledsetofthreeconicalflasksintotheappropriate5°C,15°Cand30°Cincubator.6. Attheendofeachday,removeaconicalflaskforthatdayfromeachincubatoranddeterminethe

concentrationofC6H8O6ineachofthethreeremovedflasks,asprescribedinsteps1to6inPartB.

ConclusionAnincreaseintemperaturedecreasesthestabilityofascorbicacidinfreshlypreparedpineapplejuice.


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a. Identifyacontrolledvariableusedinthisinvestigation. 1mark

b. Identifythedependentvariableinthisinvestigation.Howwasthedependentvariablemeasured? 2marks

c. Considerthemethodperformedbythestudenttodeterminetheconcentrationofascorbicacidinthisinvestigation.Identifyonestepinthestatedmethodthatimprovesthereliabilityoftheresults. 1mark


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Part B – ResultsconcentrationofI2=2.50×10

–4M

Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Mass of pineapple juice (g)

5.00 5.00 5.00 5.00 5.00

Volume of titre of I2 (mL)

28.65 27.27 27.12 27.35 27.32

d. Usingtheresultsabove,calculatetheconcentration,inmilligramsper100g,ofascorbicacidinfreshpineapplejuiceatthebeginningoftheinvestigation. 3marks

e. Commentontheprecisionofthetitrationresults.Giveyourreasoning. 2marks


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Thestudentrepresentedtheresultsoftheinvestigationonagraph,asshownbelow.

Keyafter Day 1after Day 2after Day 3

30

25

20

15

10

5

0

concentration ofC6H8O6

(mg/100 g)

0 5 10 15temperature (°C)

20 25 30 35

Concentration of C6H8O6 in pineapple juice over three days

f. Howdoesthegraphsupportthestudent’sconclusion? 1mark

g. Whatisthemostappropriatewayofgraphingtheresultstoachievetheaimofthisinvestigation?Giveyourreasoning. 2marks


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Question 10 (8marks)Implantableglucosefuelcellscanbedesignedforuseinsidethebody.Implantableglucosefuelcellsusetheglucoseandoxygendissolvedinthebloodstreamasfuel.Inanalkalineglucosefuelcell,glucose,C6H12O6,reactstoformgluconicacid,C6H12O7,accordingtotheequation

C6H12O6(aq)+2OH–(aq)→C6H12O7(aq)+H2O(l)+2e

–

Source:adaptedfromOSantiago,ENavarro,MARasoandTJLeo,‘Reviewofimplantableandexternal abioticallycatalysedglucosefuelcellsandthedifferencesbetweentheirmembranesandcatalysts’,

Applied Energy,179,2016,pp.497–522

Theexcerptaboveoutlinessomeofthebenefitsanddifficultiesassociatedwithglucosefuelcells.Answerthefollowingquestionsusingtheinformationprovidedandyourknowledgeofchemistry.

a. Discusstheefficiencyoftheutilisationofthechemicalenergyofglucoseinimplantableglucosefuelcells.Comparethistotheefficiencyoftheutilisationofchemicalenergyinthemetabolismofglucoseinthehumanbodyandinexternalglucosefuelcells.Includeanyrelevantchemicalequationsinyouranswer. 3marks

Duetocopyrightrestrictions, thismaterialisnotsupplied.


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END OF QUESTION AND ANSWER BOOK

b. i. Comparethedesignofimplantableglucosefuelcellswiththedesignofexternalglucosefuelcells. 2marks

ii. Identifyonedesignchallenge,basedonthechemistrythatoccursinanalkalineglucosefuelcell,thatisuniquetoimplantableglucosefuelcellsandsuggesthowthischallengecouldbeovercome. 3marks

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 2021

Victorian Certificate of Education 2021

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,indicatingamagnitude.Enthalpyofcombustion,∆H,forthesubstancesinthistablewouldbereportedasnegativevalues,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 = 0Thesecandifferslightlyindifferentsolvents.

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 = 0Thesecandifferslightlyindifferentsolvents.Theshiftreferstotheprotonenvironmentthatisindicatedinbold 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,BrorI) 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(variesconsiderablyunderdifferentconditions)

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

2021 Chemistry-nht Written examination

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