cambridge IGCSE chemistry study and revision guide

Author’sdedication
ToMartha,SarahandJoseph.Thankyouforeverything.


HachetteUKspolicyistousepapersthatarenatural,renewableandrecyclable
productsandmadefromwoodgrowninsustainableforests.Theloggingand
manufacturingprocessesareexpectedtoconformtotheenvironmental
regulationsofthecountryoforigin.
Orders:pleasecontactBookpointLtd,130ParkDrive,MiltonPark,Abingdon,
OxonOX144SE.Telephone:(44)01235827720.Fax:(44)01235400454.
Email:Linesareopenfrom9a.m.to5p.m.,
MondaytoSaturday,witha24-hourmessageansweringservice.Youcanalso
orderthroughourwebsite:www.hoddereducation.com
ISBN9781471894602
eISBN9781471894626
đIGCSEistheregisteredtrademarkofCambridgeInternationalExaminations.
Thequestions,exampleanswers,marksawardedand/orcommentsthatappearin
thisbookwerewrittenbytheauthor.Inexamination,thewaymarkswouldbe
awardedtoanswerslikethesemaybedifferent.
ThisbookhasnotbeenthroughtheCambridgeendorsementprocess.
âDavidBesser2017
Firstpublishedin2017by
HodderEducation,
AnHachetteUKCompany
CarmeliteHouse
50VictoriaEmbankment
LondonEC4Y0DZ
www.hoddereducation.com
Impressionnumber10987654321

Year201920182017
Allrightsreserved.ApartfromanyusepermittedunderUKcopyrightlaw,no
partofthispublicationmaybereproducedortransmittedinanyformorbyany
means,electronicormechanical,includingphotocopyingandrecording,orheld
withinanyinformationstorageandretrievalsystem,withoutpermissionin
writingfromthepublisherorunderlicencefromtheCopyrightLicensing
AgencyLimited.Furtherdetailsofsuchlicences(forreprographicreproduction)
maybeobtainedfromtheCopyrightLicensingAgencyLimited,SaffronHouse,
610KirbyStreet,LondonEC1N8TS.


Coverphoto©fox17–Fotolia
IllustrationsbyIntegraSoftwareServicesPvt.LtdTypesetinITCGalliardStd
Roman11/13byIntegraSoftwareServicesPvt.Ltd.,Pondicherry,IndiaPrinted
inSpain
AcataloguerecordforthistitleisavailablefromtheBritishLibrary.


Contents
Introduction
1Theparticulatenatureofmatter
2Elements,compoundsandexperimentaltechniques
3Atomicstructure,bondingandstructureofsolids
4Stoichiometry:chemicalcalculations
5Electricityandchemistry
6Chemicalenergetics
7Chemicalreactions
8Acids,basesandsalts
9ThePeriodicTable
10Metals

11Airandwater
12Sulfur
13Inorganiccarbonchemistry
14Organicchemistry1
15Organicchemistry2
16Experimentalchemistry
Answerstoexam-stylequestions
Index


Introduction
WelcometotheCambridgeIGCSE®ChemistryStudyandRevisionGuide.This
bookhasbeenwrittentohelpyoureviseeverythingyouneedtoknowforyour
Chemistryexam.FollowingtheChemistrysyllabus,itcoversallthekeycontent
aswellassamplequestionsandanswers,practicequestionsandexaminertipsto
helpyoulearnhowtoanswerquestionsandtocheckyourunderstanding.


Howtousethisbook
Keyobjectives
Thekeyskillsandknowledgecoveredinthechapter.Youcanalsousethisasa
checklisttotrackyourprogress.


Keyterms
Definitionsofkeytermsyouneedtoknowfromthesyllabus.


Sampleexam-stylequestions
Exam-stylequestionsforyoutothinkabout.

Student’sanswers
Typicalstudentanswerstoseehowthequestionmighthavebeenanswered.


Examiner’scomments
Feedbackfromanexaminershowingwhatwasgood,andwhatcouldbe
improved.

Examiner’stips
Advicetohelpyougivetheperfectanswer.


Commonerrors
•Mistakesstudentsoftenmakeandhowtoavoidthem.

Extended
Contentfortheextendedsyllabusisshadedgreen.

Exam-stylequestions
Practicequestionsforyoutoanswersothatyoucanseewhatyouhavelearned.


Howtorevise
Thisbookisnotintendedtogivedetailedinformationaboutthechaptersyouare
requiredtostudyfortheIGCSEChemistrycourse.Insteaditismeanttogive
conciseinformationconcerningthethingsthatyouarelikelytocomeacrossin
yourexaminations.Youhaveprobablybeenusingamoredetailedtextbookover
thetwoyearsofyourcourse.Thisbookisintendedforuseoverthesixweeks

justbeforetheexaminations.
Notwopeoplereviseinthesameway.Itwouldbefoolishtogiveprecise
instructionstoanyoneabouthowtheyshouldprepareforexaminations.
However,Iintendtomakesomesuggestionsaboutthedifferentapproachesthat
areavailable,sothatyoucanchoosethemethodsthataremostsuitableforyou.
TheonlythingIwouldstronglyrecommendaboutrevisionisthatitshould
involvewritingaswellasreading.Thosewhoreadthroughnotesorbooksas
theironlymeansofrevisingoftenfindthattheybecomedistractedandstart
thinkingaboutotherthings.Writingthingsdownhelpsyoutofocusonwhatyou
aretryingtolearn.
Anotherwaytohelpyoulearnistohighlightkeywordsandphrasesthatyou
wishtodrawattentionto.Highlightingmakesyoufocusonthingsthatyoumay
havehadproblemswithuptonow.
Afterhighlighting,youcouldrewritethehighlightedparts,leavingouttheless
importantparts.Itmayalsobeagoodideatoleaveoutthosepartsthatyou
alreadyknow.Ifyouknowthattransitionelementsareallmetals,thereisno
pointinwritingitdown,becauseyoudonotneedtoreviseit.Justfocusonthe
partsthatyouarenotsofamiliarwith.Yournoteswillbemoreconciseandmore
personalthantheinformationinthebook.Youmayprefertowritedownthe
informationinamoreeye-catchingform,suchasinadiagram.Theimportant
thingisthatitispersonaltoyouandhelpsyourrevision.
Whenyouhavemadenotesofthistype,trywritingthemout.Againjustfocus
ontheimportantkeywordsandphrases.Whenyoucanwritethemoutwithout
lookingatyournotes,youmaybeconfidentthatyouhavelearnedthisparticular
chapter.Youcantestyourselfbyansweringthe‘Exam-stylequestions’sections
ofthebookaswellaslookingatpastpaperquestionsorquestionsyouhave
attemptedduringthecourse.Ifyoucomeacrossaproblem,alwaysgobackto
yournotesandothersourcesofinformation.Thereisnoneedtoattempttimed
questionsunderexamconditionsuntilmuchnearertheexam.

Examtechnique
Themostimportantpiecesofadvicethatanyonecangiveabouthowtoapproach
anexamarenotnew.However,itiswellworthrepeatingthem,becausethe
pointsmadebelowarestillmajorcausesofavoidablelossesofmarks.
•Writeclearly.Ifexaminerscannotreadwhatyouhavewritten,theycannot
awardmarks,despitetheirbesteffortstodecipheryourwork.Inthis
technologicalage,whenhandwritingisnotusedasmuchasitwasinthepast,
itisessentialthatyouranswerscanberead.
•Usecorrectspellings.TechnicaltermsusedinChemistrymustbewritten
correctly.Incorrectspellingsdomorethancreateabadimpressionofa
candidate’swork.Ifawordisincorrectlyspelt,itoftenchangesthewhole
meaningoftheword.Anexampleisusingtheword‘alkane’insteadof
‘alkene’.Thisisnotonlyaspellingmistake,butitreplacesonewordwithan
entirelydifferentwordwhichhasanentirelydifferentmeaning.
•Readthequestionscarefully.Donotjustglanceataquestionandpickouta
fewwords.Readthewholequestionandwhenyouhavereadit,readitagain.
Aquestionmaylooklikeanotheroneyouhaveseenduringyourrevision,but
ifyoureaditmorecarefully,youmayrealisethattherearedifferenceswhich
meanthatadifferentapproachisrequiredtoanswerthequestion.
•Checkyouranswers.Whenyouhavefinishedeachquestion,readthroughit
tomakesureitmakessenseandthatitanswersthequestion.
•Donotspendtoolongonanyquestions.Ifyouspendtoolongonsome
questions,youmayfindyoudonothavethenecessaryamountoftimeto
answersomeoftheothers.Itisimportanttoanswerallthequestions.
Somecommonphrasesthatyouwillseeinquestions,andtheirmeanings,
include:
•Definetheterm/whatismeantbythetermmeansgiveadefinitionofa
wordorphrasewhichonlyappliestothatwordorphrase.Forexample,
‘Definethetermisotope’meansgiveastatementthattellssomeoneexactly

whatanisotopeis.Definitionsarefoundinthe‘Keyterms’sectionatthestart
ofeachchapter.
•Statemeansgiveabriefstatement.Noexplanationofthestatementis
required.Forexample,‘Statethenameoftheacidthatisusedtomake


magnesiumsulfate’.
•Explain/giveareasonorreasons.Thissometimesfollowsthecommand
word‘state’,i.e.‘stateandexplain’or‘stateandgiveareason’.Thismeans
youshouldgiveapieceofinformationfollowedbyabriefexplanationofwhy
youchosethisinformation.
•Outlinemeansabriefdescriptionisrequired.
•Predictmeansyouaremeanttomakeaprediction,notbasedonany
knowledgethatyouhaveremembered,butbymakingalogicalconnection
betweenotherpiecesofinformationreferredtointhequestion.
•Deducealsomeansyouarenotrequiredtogiveananswerbasedonwhatyou
haveremembered,buttosuggestalogicalconnectionbasedoninformationin
thequestion.
•Suggestmaymeanthereismorethanonepossibleanswer.Itmayalsomean
youarerequiredtoapplyyourknowledgeofChemistrytoa‘novel’situation,
e.g.anexperimentorareactionyouhavenotcomeacrossbefore.Insuch
examples,youwillbesuppliedwithsufficientinformationtomakea
reasonablesuggestion.
•Calculate/determinemeanscarryoutacalculationbasedondatathatis
provided.
•Howwouldyou…?meansgiveabriefdescriptionofanexperimentthatyou
wouldcarryout.Manyexamcandidatesanswerthistypeofquestionwithtoo
muchtheoreticalinformationratherthanbriefexperimentaldetail.

1Theparticulatenatureofmatter
Keyobjectives
Bytheendofthissection,youshould
knowthedifferentpropertiesofsolids,liquidsandgases•beabletodescribe
thestructureofsolids,liquidsandgasesintermsofparticleseparation,
arrangementandtypesofmotion•knowwhatismeantbymelting,boiling,
evaporation,freezing,condensationandsublimation•beabletodescribethe
effectoftemperatureonthemotionofgasparticles•haveanunderstandingof
Brownianmotion•beabletodescribeandexplaindiffusion
•beabletoexplainchangesofstateintermsofthekinetictheory•beableto
describeandexplainBrownianmotionintermsofrandommolecular
bombardmentandstateevidenceforBrownianmotion•beabletodescribe
andexplaindependenceofrateofdiffusiononrelativemolecularmass.


Keyterms
Melting
Theprocessthatoccurswhenasolidturnsintoaliquid
Meltingpoint Thetemperatureatwhichasubstancemelts.Eachsubstancehasa
specificmeltingpoint
Boiling
Theprocessthatoccurswhenaliquidturnsintoagas
Boilingpoint Thetemperatureatwhichasubstanceboils.Eachsubstancehasa
specificboilingpoint
Evaporation Theprocessthatoccursatthesurfaceofaliquidasitturnsintoa
gas.Evaporationcanoccurattemperatureslowerthantheboiling
pointofaliquid
Freezing
Theprocessthatoccurswhenaliquidturnsintoasolid
Freezing

Thetemperatureatwhichasubstancefreezes.Thishasthesame
point
valueasthemeltingpoint
CondensationTheprocessthatoccurswhenagasturnsintoaliquid
Sublimation Theprocessthatoccurswhenasolidturnsintoagaswithoutfirst
turningintoaliquid
Brownian
Therandommotionofvisibleparticlescausedbybombardment
motion
bymuchsmallerparticles
Diffusion
Theprocessthatoccurswhenparticlesmovefromaregionof
highconcentrationtoaregionoflowconcentration


Solids,liquidsandgases
Differencesbetweensolids,liquidsandgasesareshowninFigure1.1.

Examiner’stip
Whenaskedtodrawdiagramsofthearrangementofparticlesinsolids,liquids
andgases,solidsandgasesareusuallydrawnquitewell,buttheparticlesin
liquidsareusuallydrawntoofarapart.Inreality,themajorityofparticlesina
liquidaretouching.
Thedifferencesbetweenthepropertiesofsolids,liquidsandgases,alongwith
thereasons(basedonkinetictheory)forthedifferences,areshowninTable1.1.


Changesofstate
Figure1.2summarisesthechangesinstatethatoccurbetweensolids,liquidsand
gases.

Commonerror
•Thereisoftenconfusionbetweenboilingandevaporation.Boilingonlytakes
placeattheboilingpointofaliquid,butevaporationoccursattemperatures
belowtheboilingpoint.Puddlesofwaterevaporateonasunnyday.This
meansthatthewaterturnsintowatervapourattemperatureswellbelowthe
boilingpointofwater.Thewaterinthepuddlesdoesnotreach100°C!


Heatingandcoolingcurves
Aheatingcurveshowsthechangesofstateoccurringwhenthetemperatureof
iceisgraduallyincreased.Asimilar(butnotthesame)curveresultswhenagas
iscooledgraduallyuntilitformsasolid.Thisisknownasacoolingcurve.

Theprocessbeginswithiceatatemperaturebelow0°C.Thetemperature
graduallyincreasesuntilitreaches0°C,whichisthemeltingpointofice.At
thispointiceandwaterexisttogether.Thetemperaturedoesnotchangeuntilall
theicehaschangedintowaterwhichiswhythelineishorizontal.Asharp
meltingpoint(atonespecifictemperature)isanindicationthatanysolidispure.
Thetemperaturethenbeginstoincreaseagainuntilitreaches100°Cwhichis
theboilingpointofwater.Thetemperaturedoesnotchangeuntilallthewater
haschangedintowatervapourwhichiswhythelineishorizontalforasecond
time.Whenallthewaterhasboiled,thetemperaturebeginstoriseagainasthe
particlesinthegaseousstategainmoreenergy.

KinetictheoryWhenheatenergyisgiventoasolid,
theheatenergycausestheparticlestovibratefaster
andfasteraboutafixedpositionuntiltheparticles
havesufficientenergyformeltingtooccur.Atthe

meltingpointtheenergygainedbytheparticlesis
sufficienttoovercometheattractionbetween
particlesinthesolid.Theorderedarrangementof
particlesthenbreaksdownasthesolidturnsintoa
liquid.Asthisisoccurring,thereisnofurther
increaseintemperatureuntiltheordered
arrangementhascompletelybrokendownandallthe
solidhasturnedintoaliquid.Theenergygiventothe
particlesthencausesthemtomovefasterfromplace
toplaceuntiltheyhavesufficientenergyforboiling
tooccur.Attheboilingpointtheenergygainedby
theparticlesissufficienttocompletelyovercomethe
attractionbetweenthemintheliquidstate.The
particlesthenmoveasfarawayfromeachotheras
possibleastheforcesofattractionbetweenthemare
almostcompletelyovercome.Againthereisno
increaseintemperatureuntiltheliquidhasturned
completelyintoagas.Inthegaseousstate,thegas
particlesgainmoreandmoreenergyandmoveat
increasingspeeds.


Brownianmotion
WhenRobertBrownusedamicroscopetoobservepollengrainsonthesurface
ofwaterin1827,henoticedthatthepollengrainsmovedinarandommanner.
ThisrandommovementisknownasBrownianmotion.Thesamethingcanbe
observedifsmokeparticlesinairareobservedthroughamicroscope.
Brownianmotioniscausedbythelargerparticles(pollengrainsorsmoke

particles)beingbombardedbysmallerparticles(watermoleculesorair
molecules).Thesmallerparticlesmoveinstraightlinesuntiltheycollidewith
thelargerparticles.Becausemoreofthesmallerparticlesmaycollideonone
sideofthelargerparticlesthantheother,themovementofthelargerparticles
israndomandunpredictable.


Diffusion
Particlesinsolidsdonotmovefromoneplacetoanother.However,particlesin
liquidsmoveslowlyandparticlesingasesmovemuchfaster.
Movementofparticlesfromaregionofhighconcentrationtoaregionoflow
concentrationisknownasdiffusion.Itcanbedemonstratedexperimentallyin
liquidsandingases.