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OLevelSc

(Chemistry)v1.6

Xtra

ShortSummarizedExamNotes

Youshouldreadthroughthisbookletbeforeenteringthe

examhall!

Thisbookletcontainsextranoteshavenotbeenincludedin

theFullScienceChemistrySummarizednotes1.5booklet.

SomeofthenotesmightbethedirectanswertoyourupcomingOLevelpaper!

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RAYNotes2009

February2009

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Science(Chemistry)Summarizedversion1.6(ExtraExamNotesEdition) RAYNotes2009

(Hardcopy)Notice: ThisexamnotesbookletisafollowupreleaseafterScienceChemistryFullv1.5isreleased

onJanuary2009.

Ifyoudonothavetheversion1.5,itisstronglyrecommendedthatyoudownloaditfreeat


Usethisbookletasaquickrevisiontoolbeforeyouentertheexamhall.

AnyerrorsormistakesonthenotesshouldbeforwardedtoRayNotes2009directlyviaemail.

Copyright: Salman Bhatti

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(Hardcopy)RemembertodrawthisoutinChemistryexams!

(Solubilitytablesfromyourtextbooksarehardertomemorise)

Soluble Insoluble

Nitrate All -Sulfate Rest Ba, Ca, Pb

Chloride Rest Ag, Pb

Carbonate Group1 Rest

Remembervia:

Baked Chicken Pasta

At Pastamania

SecretTablecontributedbyMsAida(BtVSS,MOESingapore)

Thistablehelpsyouknowwhetherasaltissolubleornot.

Below: Preview of the Modified Periodic Table.Full

version

available

for

free

download

at

Ray

revision.webs.com

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(Hardcopy)

TestingforCATIONS:

Withthistable,youdontneedtomemorisethecoloursofdifferentsalts!

JustdrawoutthistableduringyourOLevels

CATION NaOH NH3

Colour Soluble or

Insoluble

Colour Soluble or

Insoluble

Cu2+ B I B S

Fe2+ G I G I

Fe3+ R I R I

Ca2+ W I - -

NH4+ N - - -

Zn2+ W S W S

Al3+ W S W I

Pb2+ W S W I

TheCATIONStableshows thecolourchangesobserved when thesaltisaddedto

SodiumHydroxide,NaOH, or AqueousAmmonia,NH3.

TestingforANIONS:

ANION Testedwith Observations

Chlorine AgNO3 AgCl White

ColourofObservationSolubleor

Insolubleinexcess

Alkali

CarbonateAcid

CO2

Carbon

Dioxide

(TurnLimewaterchalky)

Sulphate Ba(NO3) BaSO4 WhiteNitrate Al,NaOH NH3 Ammonia

(Turnredlitmusblue)

Iodide Pb(NO3)2 PbI2 Yellow

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TestforGASES:

Ammonia UsedamplitmusPaper Turnsfromredtoblue

Carbon

Dioxide

Use

Limewater

White

ppt

formed

(Turns

Chalky)

Chlorine UseDampbluelitmuspaper BleachesLitmuspaper(LitmusTurnscolourless) Hydrogen UseBurningSplint 'Pop'SoundHeard Oxygen UseGlowingSplint GlowsBrighterorBurstintoflames SulphurDioxide PlaceadropofPotassiumDichromate(VI)onFilterpaper

OrangeDichromateturnsgreen.

_________________________________________________________________________________

Mole Concept - Memorise this 4 IMPORTANT Formulas:

Massof

Sam leVolumeof

Gas

No.of

Mole

No.of

Particles

No.of

MoleMolar

Mass

No.of

Mole 24dm3

6x1023

Mole

Volume

Concentration

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RandomNotes

SomePropertiesofAllacidicsolutions

1. Allacidschangebluelitmusred2. Acidsreactwithmetalswhichareabovehydrogeninthereactivityseries.3. Acidreactswithbasestoformsaltandwater.

UsesofAmmonia

1) Manufactureofnitricacid2) Usedtoproducefertilisers

Note:

Hydrogencanbeusedasafuel! Ehtene(Alkene)isusedtomakeplastic

PotassiumDichromate(VI)

Actsasanoxidisingagent.

Ifsomething

isoxidised,

itwill

turn

from

orange

togreen!

UsedtotestforSulphurDioxidePlaceadroponfilterpaper,colourchangesfromorangetogreen.*Note: PotassiumDichromateturnsfromOrangetogreenwhenAlcoholispresent!

BecauseP.D,whichisanoxidisingagent, canoxidisealcoholintoorganicacid.

AndP.Dturnsgreenwheneversomethingisoxidised.

PotassiumIodide

Actsasanreducingagent. Ifsomethingisreduced,itwillturnfromcolourlesstobrown!

(*orifanOxidisingagentispresent)

UsesofEthanol

1) Solventfororganiccompounds.2) Tomakealcoholicdrinks.

Note:Somethingthatcontainsmorecarboncontentisstronger!

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SomeReactionrequirements:

1) Fermentation 37oC Enzymes NoOxygenpresent2) Alkeneadditionofsteam,tobecomealcohol Phosphoricacid(Catalyst) 300oC Hightemperature/pressure!3) AlkeneadditionofHydrogen,tobecomeAlkane NickelCatalyst

FractionalDistillationofPetroleum(Pleaseupdatepg43ofversion1.5withthisidealanswerbelow)

ImportantProcess(BetterAnswer):

1) Thecrudeoilisseparatedintodifferentfractionsbyfractionaldistillation2) Thecrudeoilisboiled.Eachfractionboilsatadifferenttemperature.3) Thesmaller,lightermoleculesseparateatlowboilingpoints.

Theheavierpartshavehigherboilingpoints.

4) Thefractionsarerunofffromthefractionatingcolomnatdifferentboilingpoints.

GeneralLinks

ElecticalConductivityMovingIons

HeatConductivityFreeMovingelectrons

BoilingpointStrongelectrostaticattraction

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PhysicalPropertiesofMetals

1. Goodconductorsofheatandelectricity usedtomakewires2. HighBp/Mp usedtomakecoolingutensils3. MalleableandDuctile.usedtomakejewellery

WhyisCopperrecycled?

1. Copperisexpensive2. Copperisnotseenasextensiveassomeothermetals.

NaminganEster

Whenyounameordrawthestructureofester,followthisFormula:

(DevelopedbyMsAida,BtVSSSingapore)

NOLmeansNameAlcoholFirst

NOL DAC

DACmeansDrawAcidFirst

SoinEthylPropanoate(Ester), theoneontheleftisAlcohol,rightisAcid.

PropanoicAcid(Acid)

Ethanol

Alcohol

Butwhenyoudrawthechemicalstructure,theAcidpartmustbeontheleftside,Alcoholontherightside.

__________________________________________________________________

3AmphotericOxides:

1. AluminiumOxide2. ZincOxide3. LeadOxide

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(Hardcopy)

OH O||

C OH

Whenyouseethisinachemical

structure,itisanAcid

When youseethisinachemicalstructure,itisanalcohol.

Alkane:CnH2n+2

Alkene:CnH2n

Alcohol:CnH2n+1OH

Acid:CnH2n+1CO2H OR CnH2nO2

Thisnewformulaworks

thesameastheoriginal!

Itishighlyrecommended

youusethisformulato

avoidconfusions.

__________________________________________________________________

Oxidation

1. GainOxygen2. LossHydrogen3. Losselectrons4. Increaseinoxidationstate

Reduction

1. Gainhydrogen2. Gainelectron3. LossOxygen4. Decreaseinoxidationstate

Note:Whencheckingifasomethingisoxidisedorreduced,usetheoxidationstatetocheck!Thisproduces100%

Correctanswer. Ifyouchosetousethelose/gainofoxygenorelectrons,youranswermightnotbecorrect.

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Proteinundergoeshydrolysistoformaminoacids!

Remember4alkalis(Solubleoxides/Hydroxides)

1. PotassiumHydroxide2. SodiumHydroxide NaOH3. CalciumHydroxide Ca(OH)24. Ammonia NH3

__________________________________________________________________

ReactivitySeries:

1. Potassium2. Sodium3. Calcium4. Magnesium5. Aluminium6. Zinc7. Iron8. Lead9. Hydrogen10.Copper11.Silver12.Gold

*Justrememberthephrase:

Playingsoccercanmakeallzappy, IloveHannacozshesgorgeous

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(Hardcopy)

MrofC60: (Carbonmolecule)

12x60=720

__________________________________________________________________

Exothermic

AbsorbenergyBreakbonds AbsorbheatTesttubeturncold Eg.Icemeltingtowater(Absorbenergytobreakbonds)

Endothermic

GiveoutenergyBondForming ReleaseHeatTesttubeturnshot.

_____________________________________________________________

Hydrogenusedasafuel

Etheneusedtomakeplastics

SolventsuitableforChromatography:Ethanol

__________________________________________________________________

ChemicalReactionsinBlastFurnace

1. Cokeburnsinairtoproducecarbondioxideandlotsofheat.C+O2CO2

2. CarbonDioxidereactswithmorecoketoproduceCarbonMonoxide.C+CO22CO

3. CarbonMonoxidereactwithiron(III)Oxidetoproducemolteniron&carbondioxide.3CO+Fe2O33CO2+2Fe

4. Impuritiesinmoltenironareremovedbylimestone.CaCO3CaO+CO2

5. CalciumOxideformedcombineswithSilicapresentintheoretoformslag, whichistappedout.

CaO+SiO2CaSiO3

#ImpurityinBlastFurnace: Silica

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(Hardcopy)

Process:Cracking

ALKANESTRONGHEATALKENE

Cracking A reaction in which big hydrogen molecules are broken into

smaller molecules by heat.

______________________________________________________

Group 7 - Halogens

Fluorine: Pale yellow gas Chlorine: Yellowish Green gas Bromine: Reddish Brown liquid Iodine: Black Solid Astatine: Black Solid

*DownloadtheModifiedPeriodicTableformorenotesonPeriodicTable


Note:whenBromineisaddedtoIodide, Gotreaction! Displacementreaction

(BrominemorereactivethanIodide)

Forgroup7elements,themorereactiveelementswilldisplacethelessreactiveelementsinreactions.

Whyplastic

cause

pollution?

Itisnonbiodegradable_____________________________________________________________________________

DescribeatestforChlorine

Itturnsthebluelitmuspaperredfirstthenwhite.(Chlorinebleacheslitmuspaper)

HowtodistinguishwhichisAcid,whichisalcohol

Test:PutsomeSodiumCarbonateResultforAlcohol: Noreaction

ResultforAcid: Agasisreleased

BecauseAlcoholdoesnot

reactwithcarbonate!

BecauseAcidcanreactwithcarbonate

ACID+CARBONATE

SALT

+WATER

+CARBON

DIOXIDE

GAS

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(Hardcopy)

UsesofNobleGases:

1. Helium:FillBaloons(LowDensity)2. Neon:LightTubes3. Argon:LightBulbs(unreactive)

__________________________________________________________________

*Commonquestions:DoesmetalliberatehydrogenfromDiluteHydrochloricAcid?

YesMorereactive

NoLess

reactive

Isthemetalreducedbyheatingwithcarbon?

YesLessReactive NoMoreReactive

HowdoescalciumionshowthatCalciumisametal?

Metalsformpositiveions.Calciumhas3valenceelectronsthusitisametal.________________________________________________________________

#Methodsofpreparingsalts

1)Titrationmethod(Formakingallgroup1salts) use:Soluble+Soluble

2)Formakingsolublesaltsnotfromgroup1, use:Soluble+Soluble

Soluble+Insoluble

3)PrecipitationMethodFormakingInsolublesalts, use:Soluble+Soluble

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(Hardcopy)

Important: Memorisethestepsofpreparingsalts:

TitrationMethod(SolubleBase+Acid)

ToprepareanysaltthatisfromGroup1.(Eg.PreparingSodiumSulfate)1) Add25cmofacidtoaconicalflask2) Addafewdropsofindicator.(eg.PhenolPhthalein)3) AddSodiumHydroxideusingaburetteuntilindicatorchangescolour.4) Repeatexperimentwith25cm3ofSulfuricAcidbutNOindicator!5) AddsamevolumeofSodiumHydroxide.6) SodiumSulfateisobtainedbyevaporating&crystalisingthesalt.

_____________________________________________________________________________

PrecipitationMethod(Soluble+Soluble)

ToprepareanyInsolublesalt.1) Addsolublesaltwithsolublesalt.2) Filterouttheprecipitate.3) Washtheresiduewithdistilledwater.4) Leavetheresiduetodry.

***MUSTKNOWformulas:

Amonium NH4+

Ammonia NH3

Hydroxide OH

Nitrate NO3

Carbonate CO32

Sulfate SO42

HydrochloricAcid HCl

SulfuricAcid H2SO4

NitricAcid HNO3

Oxygen O2

SodiumChloride

NaCl

CarbonDioxide CO2

Memorisethistemplate,

andreplacetheunderlined

wordsduringexams!

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(Hardcopy)

Whyimportanttorecyclemetals?

1) Itcanhelpconservethemetaloresintheground,makingitlastlonger.2) Itsavesthemoneyneededforextractionofmetals.

_______________________________________________________________________

#Whypeopleconcentrateonrecyclingcopper? Copperismorescarce,hencemoreexpensivethaniron.AdvantagesofRecycling:

1. Metaloresinthegroundcanlastlonger.2. Moneysavedinenergyneededtoextractnewmetalsfromore.3. Scrapmetalisremovedfromtheenvironment,

preventsland&waterpollutionduetocorrosion.

DisadvantagesofRecycling:

1. Expensivetocollectstrapmetalsfrommanysources2. Metalfumesproducedinmeltingofscrapmetalscancausepollution.

_______________________________________________________________________

MembersofHomologousserieshave:

DifferentEmpiricalformula DifferentPhysicalPropertiesRemember:Abaseis ametaloxideorhydroxide!

_____________________________________________________________________________

#Whichcompound

forms

an

acidic

solution

with

water??

Ans:CarboxylicAcid

(Acid+WaterAcidicSolution)

*NotethatexcessAcidorAlkalicanpollutetheenvironment!!

Ifaquestionasksforthechemicalpropertiesofacid,avoidwriting

Itturnsbluelitmuspaperredwriteacidreactswithbasetoform...

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(Hardcopy)

Effectsofacidrain

1) Corrodescementandstonesusedinbuildings2) Killsfishesinfreshwaterlakes.3) Makesagriculturallandacidicresultingincropsgrowingpoorly.

ImportantTip:

AnyquestionthatwantsyoutowritetheIonicEquationofanyneutralisationreaction,

justwritethisout:

H++OH

H2O___________________________________________________

Notethatsaltdonotreactwithacid!

Eg. Copper(II)NitratedonotreactwithSulphuricAcid

Salt

However,Copper(II)OxidewillreactwithSulphuricAcid!

+ Gotreaction

AcidBase

ChemicalPropertiesofGroup7elements

1) Allarediatomicmolecules.2) Allarecoloured.3) Allareoxidisingagents.4) Allarenonmetals.

PhysicalPropertiesofGroup7elements

1) TheyhavelowMp/BpTheyarepoorconductor

3) Theyarecolouredsubstances,colourbecomedarkerdownthegroup2)

ofelectricity

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(Hardcopy)

oremoveSulphur

Ans:Use:

SlakedLimeciumHydroxide

tantNote:Isotopeshave:

Samechemicalproperties(Becozsameno.ofvalenceelectrons)ties

try, LimeisAlkaline! NOTsameasLEMON!!!

Ironsreactsrapidlyinsteam,slowlyincoldwater

__________

Howt Dioxidefrom......??

Acidic

CalImpor

Differentphysicalproper

Info: Inchemis

________________________________________________________

Air

1%OtherGas(mainlyargon) 20%Oxygen 79%Nitrogen

Others: CO2,Water

oleumFractionsractionalDistillationofPetroleumprocessatPg7)

1. PetroleumCylindergasforcooking

Kerosene(Paraffin)Jetfuel

DieselFuelfor

LubricatingOil

BitumenSurfacing

Vapour

Petr (F

2.Petrol

Fuelforcars

3. NapthaMakingChemicals4.5. bus6. Wax,Polishes,Lubricants7. roads

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(Hardcopy)

articlesTheory

Mustmemorisethefollowing:

P

#Factors

affecting

speed

of

reaction

1) Concentrationofsolutiontion,thefastertherateofreaction.

ertogether sotheycollidemorefrequently

________________________

ressure

Thehighertheconcentrationofsolu

Becausetheparticlesareclos

andsothereweremorefrequentreactions.

Note:Onlyappliestoreactionsofsolutions.

_____________________________________

2) P

heparticlesaresqueezedclosertogether,sotheycollidemore

_______________

articlesizeofsolid

Thehigherthepressure,thhigheristherateofreaction.

Becauset

frequentlyandsothereweremorefrequentreactions.

Note:Onlyappliestoreactionsofgases.______________________________________________

3) P

ceareaofthesolidincreasessoreactingparticles

dsothere

morefrequentreactions.

____________________________________

emperature

Thesmallertheparticlesize,thehighertherateofreaction.

Becausethetotalsurfa

ofliquidandgasescollidemorefrequentlywiththesurfacean

are

Note:Onlyappliestoreactionsofsolids.

_________________________

4) T

ertemperature,theparticleshavegreaterkineticenergy,

Thehigherthetemperature,thefastertherateofreaction.

Becauseathigh

sotheyreactmoreoftenwhentheycollide.

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(Hardcopy)

VeryReactiveMetalsFor:

(Decomposingmetalcompoundwithelectricity) Potassium

Sodium

Calcium

Magnesium

_________________________________________________

ModeratelyReactiveMetalsZinc

Iron

Lead

___________________

LowReactivityMetalsCopper

Silver

v1.6booklet)

Foundmistakesonnotes? Sendmeanemail. Correctionswillbemadewithin2days.

*Hard

copy

notes

for

other

subjects

are

also

available

a http://www.ray

revision.webs.com

*MethodsofextractionThemethoduseddependsonhowreactiveisthemetals!

Electrolysis

Aluminium

Heatingmetaloxidewithcoke For:

______________________________

Heatingmetalcompoundsinair For:

(Endofexamnotes

t

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