Cambridge International Examinations Cambridge … and A Level...READ THESE INSTRUCTIONS FIRST Write...

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Transcript of Cambridge International Examinations Cambridge … and A Level...READ THESE INSTRUCTIONS FIRST Write...

  • READ THESE INSTRUCTIONS FIRST

    Write your Centre number, candidate number and name on all the work you hand in.

    Write in dark blue or black pen.

    You may use an HB pencil for any diagrams or graphs.

    Do not use staples, paper clips, glue or correction fluid.DO NOT WRITE IN ANY BARCODES.

    Answer all questions.

    Electronic calculators may be used.

    You may lose marks if you do not show your working or if you do not use appropriate units.

    A Data Booklet is provided.

    At the end of the examination, fasten all your work securely together.

    The number of marks is given in brackets [ ] at the end of each question or part question.

    CHEMISTRY 9701/22

    Paper 2 AS Level Structured Questions October/November 2018

    1 hour 15 minutes

    Candidates answer on the Question Paper.

    Additional Materials: Data Booklet

    Cambridge International Examinations

    Cambridge International Advanced Subsidiary and Advanced Level

    This document consists of 13 printed pages and 3 blank pages.

    [Turn overIB18 11_9701_22/6RP

    © UCLES 2018

    *5824876239*

  • 2

    9701/22/O/N/18© UCLES 2018

    Answer all the questions in the spaces provided.

    1 ThemodelofthenuclearatomwasfirstproposedbyErnestRutherford.Hedevelopedthismodelonthebasisofresultsobtainedfromanexperimentusinggoldmetalfoil.

    (a) Completethetablewithinformationfortwooftheparticlesinanatomof197Au.

    particlerelative

    mass

    relative

    chargelocation

    within atom

    totalnumberinan atom of 197Au

    electron 0.0005 –1 79

    neutron nucleus

    [4]

    (b) Statethetypeofbondingingold.

    .............................................................................................................................................. [1]

    (c) Asampleofgoldfoundintheearthconsistsofonlyoneisotope.

    (i) Explainwhatismeantbythetermisotopes.

    .............................................................................................................................................

    .............................................................................................................................................

    ....................................................................................................................................... [2]

    (ii) Adifferentsampleofgoldcontainsmorethanoneisotope.

    Suggestwhythisdifferentsampleofgoldhasthesamechemical properties as the sample found in the earth.

    .............................................................................................................................................

    ....................................................................................................................................... [1]

  • 3

    9701/22/O/N/18© UCLES 2018 [Turn over

    (d) Tumbaga is an alloy of copper and gold.A sample of tumbaga was analysed. Themassspectrum of the sample is shown.

    63 65

    56.36

    25.14

    197m / e

    percentage

    abundance

    0

    x

    (i) Calculatethepercentageabundanceofgold,x,inthesampleoftumbaga.

    x = .............................. % [1]

    (ii) Calculatetherelativeatomicmass,Ar,ofthecopperpresentinthissample. Giveyouranswertotwo decimal places.

    Ar (Cu) = .............................. [2]

    [Total: 11]

  • 4

    9701/22/O/N/18© UCLES 2018

    2 Thetablegivessomedataforelementsinthethirdperiodandsomeoftheircompounds.

    element Na Mg Al Si P S

    typeofbonding metallic covalent covalent

    formulaofoxide P4O10 SO2

    formula of chloride NaCl MgCl 2 SCl 2

    (a) Completethetabletoshowthebondingintheelements,andtheformulaeoftheiroxidesandchlorides. [3]

    (b) SCl 2isformedinthefollowingreaction.

    S2Cl 2(l) + Cl 2(g) 2SCl 2(l) ΔH = – 40.6 kJ mol–1

    (i) Completethe‘dot-and-cross’diagramtoshowthebondinginamoleculeofSCl 2. Show outerelectronsonly.

    [1]

    (ii) CompleteandfullylabelthereactionpathwaydiagramforthereactionbetweenS2Cl 2 and Cl 2.Includelabelsforactivationenergy,Ea,andenthalpychangeoftheforwardreaction,ΔH.

    energy

    progress of reaction

    S2Cl 2(l) + Cl 2(g)

    [2]

  • 5

    9701/22/O/N/18© UCLES 2018 [Turn over

    (c) (i) Ontheaxes,sketchthetrendinmeltingpointoftheelementsNatoS.

    melting point

    of element

    Na Mg Al Si P S

    [1]

    (ii) Givethreestatementstoexplainyoursketch.

    1 ..........................................................................................................................................

    .............................................................................................................................................

    2 ..........................................................................................................................................

    .............................................................................................................................................

    3 ..........................................................................................................................................

    .............................................................................................................................................

    [3]

    (d) Write an equation for the reaction of P4O10 with water.

    .............................................................................................................................................. [1]

    (e) SO2canbereleasedintotheatmospherewhenfossilfuelscontainingsulfurareburnt.

    StateandexplainoneenvironmentalconsequenceofthereleaseofSO2 into the atmosphere.

    ....................................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    .............................................................................................................................................. [2]

  • 6

    9701/22/O/N/18© UCLES 2018

    (f) Theelementsinthethirdperiodshowageneralincreaseintheirfirstionisationenergiesfromlefttoright.

    Identify two pairs of successive elements in the third period that do not agree with thisstatement.

    Foreachpair,explainwhythechangeinionisationenergydoesnotagreewiththisstatement.

    Use of the Data Booklet may help you to answer this question.

    pair 1 ..........................................................................................................................................

    explanation ................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    pair 2 ..........................................................................................................................................

    explanation ................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    ....................................................................................................................................................

    [4]

    [Total: 17]

  • 7

    9701/22/O/N/18© UCLES 2018 [Turn over

    3 Trihalomethanes are organicmolecules inwhich three of the hydrogen atoms ofmethane arereplacedbyhalogenatoms,forexampleCHF3.

    (a) TheequationshowsareactiontoproduceCHF3.

    CHI3(s)+3AgF(s) CHF3(g)+3AgI(s)

    Usethedatatocalculatetheenthalpychangeofreaction,ΔHr,forthisformationofCHF3.

    compoundenthalpychangeof

    formation,ΔHf / kJ mol–1

    CHI3(s) –182.1

    CHF3(g) – 692.9

    AgF(s) –204.6

    AgI(s) – 61.8

    enthalpychangeofreaction,ΔHr = .............................. kJ mol–1 [3]

  • 8

    9701/22/O/N/18© UCLES 2018

    (b) ThegraphshowstherelationshipbetweenpV and patagiventemperatureforCHF3 and an idealgas.

    pV

    0 200 400 600

    p / atm

    800 1000

    CHF3

    ideal gas

    (i) CHF3isnotanidealgas.

    State threebasicassumptionsthatscientistsmakeaboutthepropertiesofidealgases.

    1 ..........................................................................................................................................

    2 ..........................................................................................................................................

    3 ..........................................................................................................................................

    [3]

    (ii) ExplainwhyCHF3deviatesfromthepropertiesofanidealgasatpressuresgreaterthan300 atm.

    .............................................................................................................................................

    .............................................................................................................................................

    .............................................................................................................................................

    ....................................................................................................................................... [2]

  • 9

    9701/22/O/N/18© UCLES 2018 [Turn over

    (c) Adifferenttrihalomethane,CHCl 3,reactswithO2toproducecarbonyldichloride.HCl(g)isalsoreleased as a product of this reaction.

    C

    carbonyl dichloride

    ClCl

    O

    (i) WriteanequationforthisreactionofCHCl 3 with O2.

    ....................................................................................................................................... [1]

    (ii) TheconversionofCHCl 3tocarbonyldichloridecanbemonitoredbyinfra-redspectroscopy. Theinfra-redspectrumofcarbonyldichlorideisshown.

    100

    50

    0

    transmittance

    4000 3000 2000

    wavenumber / cm–1

    1500 1000 700

    On the infra-red spectrumof carbonyl dichloride identifywithanX theabsorption thatwould notbepresentinaninfra-redspectrumofCHCl 3.

    Explainyouranswer.

    .............................................................................................................................................

    .............................................................................................................................................

    [2]

    (iii) Suggestanotherdifferencebetweentheinfra-redspectraofCHCl 3andcarbonyldichloride.

    .............................................................................................................................................

    ....................................................................................................................................... [1]

    [Total: 12]

  • 10

    9701/22/O/N/18© UCLES 2018

    4 Thediagramshowsareactionsequencestartingfromethanal.

    C P

    ethanal

    H3C

    H3C

    CO2H

    CO2H

    OH

    CC

    C

    RQ

    H

    H

    H

    O

    C

    S

    H3C

    O

    H

    CO2H

    HCN and NaCN

    reaction 1

    H2SO4(aq)

    reaction 2 reaction 3

    reaction 4

    H

    (a) (i) Draw the displayed formula of P.

    [1]

    (ii) Namethetypeofchemicalreactionthatoccursinreaction3.

    ....................................................................................................................................... [1]

    (iii) Write an equation to represent reaction 4.

    Use[O]torepresenttheoxidisingagent.

    ....................................................................................................................................... [1]

    (iv) Statethereagentsandconditionsforreaction4.

    ....................................................................................................................................... [1]

  • 11

    9701/22/O/N/18© UCLES 2018 [Turn over

    (b) Compound Qisformedasamixtureoftwoopticalisomers.

    (i) Explainwhatismeantbythetermoptical isomers.

    .............................................................................................................................................

    .............................................................................................................................................

    ....................................................................................................................................... [1]

    (ii) Draw the two optical isomers of Q,showingclearlytheirthree-dimensionalstructures.

    [2]

    (c) Rcanbeusedtomakeapolymer,W,intwosteps.

    R W

    addition

    polymerisation

    intermediate

    polymer

    NaOH(aq)

    Draw one repeat unit of W.

    [3]

  • 12

    9701/22/O/N/18© UCLES 2018

    (d) Compound Z,H2C=CHCH3,isproducedfromR.

    Zcanbeusedinatwo-stepprocesstoproduce2-aminopropane.

    (i) In the first step,Z reactswithHBr to form two products.The structure of the productdependsonwhichintermediateisformed,intermediateI or intermediate II.

    intermediate I

    CH3

    C

    H3C

    H

    +

    intermediate II

    CH3

    C

    H

    H H

    H

    C+

    ExplainwhyintermediateIismorelikelytoformthanintermediateII.

    .............................................................................................................................................

    .............................................................................................................................................

    .............................................................................................................................................

    ....................................................................................................................................... [2]

    (ii) When intermediate Iforms,theproductofthefirststepisT.

    CompletethediagramtoshowthemechanismfortheconversionofZ to T. Includeallrelevantcharges,partialcharges,curlyarrowsandlonepairs.

    C

    CH

    HH

    Br

    H

    CH3

    CH3

    C

    H3C

    H

    +H3C

    Br

    H

    C

    TZ

    CH3

    [3]

    (iii) Tcanthenbeconvertedto2-aminopropane.

    NH3

    ethanolH3C

    Br

    H

    C

    T

    CH3 H3C

    NH2

    H

    C

    2-aminopropane

    CH3

    Name the mechanism for this conversion.

    ....................................................................................................................................... [1]

  • 13

    9701/22/O/N/18© UCLES 2018 [Turn over

    (e) (i) Compound S,CH3COCO2H,canbereducedbyLiAlH4.

    Completetheequationusingstructuralformulaetorepresentthisreaction. Use[H]torepresentthereducingagent.

    CH3COCO2H+ ............................................................................................................ [2]

    OtherreducingagentscontainingGroup1metalcationsincludeLiBH4,NaBH4andKBH4. Thestrengthofthereducingagentdependsonthesizeofitscation.

    (ii) GivetheelectronicconfigurationoftheNa+ cation.

    1s2 ................................................................................................................................. [1]

    (iii) SuggestwhyionicradiusincreasesdownGroup1.

    .............................................................................................................................................

    .............................................................................................................................................

    ....................................................................................................................................... [1]

    [Total: 20]

  • 14

    9701/22/O/N/18© UCLES 2018

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    9701/22/O/N/18© UCLES 2018

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  • 16

    9701/22/O/N/18© UCLES 2018

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    To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International

    Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after

    the live examination series.

    Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local

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