chemistry full v1.5
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RAYNOTES2009
09
OLevelSc(Chemistry)v1.5EasynotessummarizedforOLevels
Hong Ray Corporations
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Chapter1Summary
1) Matterismadeupofparticles.
Solid (Fixedshape,HighDensity)
Particlesclosetogether, OrderlyArranged,
Heldbystrongforcesinfixedpositions
Liquid (Nofixedshape,HighDensity)
Particlesclosetogether,
NOTinorder,
Strongforces, (betweenparticles)
Vibrate&Freetomove
Gas
(No
fixed
shape,
Low
density)
ParticlesFarapart
Weakforces(Betweenparticles)
Freetomovearound
Pressureisduetotheparticlesbouncingoffwallsofcontainer.
ApparatusTomeasure:
Massofchemical,use ElectronicBalance
Temperature,use Thermometer
Vol.ofgas,use MeasuringCylinder OR Burette OR Pipette.
ChangesofState
1) Melting (SolidLiquid)
Particlesgainenergy
Vibratemore
Occursatmeltingpoint
Endothermic*Reaction (Becauseparticlesgainenergytobreakbonds)
2) Freezing(LiquidSolid)
Occursatfreezingpoint(Alsothem.p.ofpuresubstance) Exthothermic*Reaction (Becauseparticlesgiveoutenergytoformbonds)
*ENdothermicreactionmeansheatorenergy ENTER(absorbed/gained) tobreakbond!
*EXothermicmeansheat,energy EXIT(giveout/lose) toformbonds!
Notethat forboth Freezing & Melting, temp.remainsconstantduringtheprocess!
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Chapter2Summary
SEPERATIONOFMIXTURES2.1MixTURES&Compounds
1) Compound 2ormoreelementschemicallyjoinedtogether
Eg.SodiumChloride
ContainsCovalentorIonicBonds
2) Mixtures
2ormoresubstanceswhicharenotchemicallyjoinedtogether
Eg.IroninSulphurpowder.
Canconsistof:
Elements (Iron&Sulphurpowder)
Compounds (Saltinwatersalt&waterarebothcompounds) Elements+Compounds (Air)
#PureSubstances
1) Fixedcomposition
2) FixedMp/Bp
3) Producesonly1spotonchromatogram
4) Allmoleculessame(equal)
#Mixture
1) VariableComposition
2) VariableBp/Mp
3) 2ormorespotsonChromatogram
4) 2ormorediff. molecules
Personal Tips: Man Becomes what he thinks about Mooris Goodman
- Visualize yourself being able to understand this set of notes perfectly. By truly believing, it must be Fact.
PerformanceimprovementTips: Listentoinstrumentalmusics; (BoroqueisNOTrecommended)asitcan
makeyoutired
TryidealmusicssuchasFreeasabirdandAdaywithyoubyOmar. Alsomakesureyoulistenusing
earpiece,NOTspeakers!
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2.2Purification
(NotethatmixturesareImpuresubstances)
*Solublemeanscandissolveinwater(eg.Salt)
*Insolublemeanscannotdissolveinwater(eg.Sand)
SAND&WATER
CopperSulphatecrystalsfrom
CopperSulphatesolution
Waterfromseawater
Petroleumtopetrol/diesel
Separatingdyesininks
1) Insolublesolid & LiquidFiltration
2) Solid&LiquidsolutionCrystallization
(Obtainingsolid)Solute
3) Solid&LiquidsolutionDistillation
(ObtainingLiquid)Solvent
4) 2Liquidsmixed(Miscible)FractionalDistillation
5) MixtureofOrganicCompoundsChromatography
(Eg.ColourDyes)
NotethatMisciblemeansmixable (Abletobemixed)
_____________________________________________________________________________________
#FiltrationSeparatingsolidfromliquid
Possiblebecoz:
Liquidparticlessmallenoughtogothrufilterpaperpores
Solidparticlestoolarge.
SolidobtainedResidue
LiquidobtainedFiltrate
#CrystalisationObtainingsolidfromSolid&LiquidsolutionOR
Formationofcrystalsfromacoolingliquid/Saturatedsolution
Process:
1. Dissolvesolidinsolventtogivesolution.
2. Solutionheated
toevaporate
solvent.
3. >>Producesahotsaturatedsolution.
4. Crystalsofpuresolidformedoncooling.
Generalnotes:
ASATURATEDsolutionmeansnomoresolidcandissolveinit
Anyquestionthatwantsthemethodtoobtain(make)~crystals, theprocesswillbeCrystalisation!
Eg. WhatmethodisusedtomakeCopperSulphateCrystals? Ans: Crystalisation.
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#DistillationObtainingpureliquidfromsolution(Eg.Toobtainpurewaterfromseawater)
Process:
1. Heatsolutioninflask.
2. Thesolutionboils3. Pureliquidturnstovapour,leavetheflask.
4. Vapourcooledbycondenser,changesbacktoliquid
5. >>LiquidobtainediscalledDistillate(Collectedinconicalflask)
Possiblebecause:
PureliquidchangetogaseasilyLowBP
Soliddoesnotboil(soremainsinflask)HighBP
GeneralNote: Theconstanttemperatureofprocess=BoilingPointofpureliquid
#FractionalDistillationSeperating2liquidswhicharemixed (Miscible)
Process:
1. Mixtureheated
2. LiquidwithlowestBPcomesout1st,(attopoffractionatingcolomn)
3. Cooledbycondenser, Changesbacktoliquid
4. >>LiquidobtainediscalledDistillate(Collectedinconicalflask)
#Chromatography ForSeperating/IdentifyingmixturesofOrganiccompounds.
ForSeperatingmixturesofmetalions.
Personal Tips: Chemistry is actually very easy! I used to get D7 for my Chemistry, but with perseverance for 3 months, I scored A1 in
my O-Levels 2008!
- If you cant do a question, use a red-pen to circle it, fold the page! Arrive school earlier, clear doubts with teachers outside the
staffroom.
- You CAN ask ANY of the Science Teachers in your school!
- Be Brave to take the 1st step, and everything will be smooth after that.
Take the first step in faith. You dont have to see the whole staircase, Just take the first step Martin Luther King
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Chapter3Summary
STRUCTUREOFATOMS3.1Particlesinatoms
Atomsaremadeupof3particles:
1) Protons
Mass:1
Charge:+1
Location:Nucleus
2) Neutron
Mass:1
Charge:0
Location:
Nucleus
3) Electron
Mass:1
Charge: 1
Location:ontheshells(aroundnucleus)
GeneralNotes:
Ifanatomiselectricallyneutral, No.ofproton=No.ofneutrons
No.ofprotons=No.ofelectron
Nucleonnumbersumofproton&neutron. (Alsocalledmassno.)
3.2Isotopes
IsotopesAtomsofsameelement, butwithdiffno.ofneutron.
(Sameprotonno.,diffneutronno.)
Note:
Allelementsform Isotopes
IsotopeshaveSAMEchemicalproperties (becozhavesameno.ofoutershellelectrons)
*Notethatthechemicalproperties aredeterminedbythe numberofOutershellelectrons.
If2~ havesameno.ofoutershellelectrons, theywillhavesamechemicalproperties.
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3.3Electronsarrangementinatoms
Anatomwithstableelectronicstructurewillhave 2 OR 8valenceelectrons*
Eg:
2.8.8 8electroninoutermostshell (or2valenceelectron)
2.8 8electroninoutermostshell
2 2electroninoutermostshell
Valenceelectrons electronsontheoutermostshell.
_____________________________________________________________________________________
3.4Ions
IonsParticleswithapositiveornegativeelectriccharge.
Ifanatomdoesnothas2 or8valenceelectrons, itisNOTSTABLE!
Notstablemeans itwillreact bygainingorlosingelectrons,justtomakesuretheygeteither
an2or8 intheirno.ofvalenceelectrons.
So,whentheygainorloseelectrons,theywillform Ions
Eg. Anatomwithelectronicstructure 2.8.8.7 willneedtogain 1electrontoform 2.8.8.8(STABLE)
2.8.3 willhavetolose 3electronstoform 2.8 (STABLE)
Whenanatom:
Gainelectron, itformsNEGATIVE ions
Loseelectron, itformsPOSITIVEions
Generalnotes:
NegativeIon
Formedwhenanatomgainelectron
Formedbynonmetals
PositiveIon
Formedwhenatomloseelectron
Formedbymetals
Atomsformionstoobtainelectronicstructureofnoblegas (NoblegasareSTABLE)
*ImportantFact: Metalsloseelectrons,nonmetalsgainelectrons
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Chapter4Summary
CHEMICALBONDS4.1CovalentBonding
CovalentBondsFormedbetweenatomsofnonmetals&nonmetals
ADoublebond meanseachatomprovides2electron
Total=4electronsbeingshared
4.2IonicBonding
IonicBonding Formedbytransferofelectronsbetweenmetals&nonmetals,
formingpositive&negativeions.
IonicBondistheforceofattractionbetween +ve & ve ions.
Eg.2atomsareionicallybonded; Sodium&Chloride.
Sodium:2.8.1 (Needstolose1) afterlosing1toChloride,itbecomesPOSITIVEionwith2.8
Chloride:2.8.7 (Needstogain1) aftergaining1fromSodium,becomeNEGATIVEionwith2.8.8
>>Then,theyllbecalledSodiumChloride (Acompound) Becozitschemicallyjoinedtogether..
GeneralExamples:
SodiumChlorideIonicBond; becozSodiumisametal,Chlorineisnonmetal.
MagnesiumSulphateIonicBond; becozMagnesiumisametal, Sulphurisanonmetal
*RemembertonametheMETAL1stthentheNONMETAL!
Eg. WedonotnameChlorideSodium, WeonlynameSodiumChloride!
SowhyisntitcalledSodiumChlorine? AllelementsinGroupVIIchangestheirtailnamewithide
i.e. Fluorinebecomes Fluoride whenitformsacompound(eg.LithiumFluoride)
Iodinebecomes Iodide whenitformsPotassiumIodideCompound
CarbonDioxide(CO2)CovalentBond; becozCarbonisanonmetal, Oxygenisalsononmetal
Methane(CH4)CovalentBond; becozMethaneconsistofCarbon&Hydrogen
Bothisnonmetal
*Mustremember thatHydrogenisconsideredaNONMETAL!
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4.3FormularofIonicCompounds
Theformularcanbeexplainedinastorymode..
FindingformularofBariumChloride, ItisNOT assimpleasBaCl!!
*RememberthatIonicCompounds Transferofelectrons!*Metalsloseelectrons,nonmetalsgainelectrons
*Gainelectron+veions / Loseelectrons veions
Readstorymode:(Forweakerstudents)
Bariumisfromgroup2, henceithas2valence(outershell)electrons
Itisametal Soithasto LOSE 2electronsto become stable!
Sowhenitloses2electrons, itformspositiveionswiththecharge +2
SoBariumisBa2+
Chlorineisfromgroup7, ithas7valenceelectrons
ItisanonmetalsoIthastoGAIN 1electron tobecomestable!
Whenitgains1electron, itformsnegativeionswiththecharge 1
Thuswhenyouput2together, itwillbe Ba2+
Cl1
Becausetheruleisthatthe+vechargemustbalancethevecharge,
Sotomakeisbalance, justwriteisas BaCl2 //Answer
Personal Tips: Feel grateful for receiving this set of notes, and you will experience more great things coming..
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TheShortcutmethodbelowwillworkeverytime!
Itsthebestmethod todeterminetheformularofioniccompound!
Question: FindtheformularofMagnesiumSulphate (MgS)
1. Writesymbolsofelementssidebyside (Metaldennonmetal)
MgS
2. Writetheionformedwhentheybecomestable
Mg2+
S1
MgbecomesMg2+
becauseitisfromgroup2,has2valencesoitlose2toformMg2+
ion.
SbecomesS1
becauseitisfromGroup7, has1valence, sohastogain1toformS1
ion
3.Crossthecharges (Ignoringthe+andsigns)
Mg2+ S
1
Mg1 S2 MgS2 (Ans)
Practice makes perfect! Do not give up on your chemistry Clear doubts as often as possible
If you are not interested in this subject, continue to clear doubt, and when you get good results,
youll love chemistry! - Hong Ray (Former Student)
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4.4 PropertiesofCovalent&IonicCompoundsNotethatisthistopichas alwaysbeentested everyyear,and willcontinuetobetestedinGCEOLevelexams!!
Justmemorisetheproperties:
#
Covalent
1. Doesnotconductelectricityinanystate (Becozdoesnotcontainions)
2. Lowmeltingpointlessthan200oC (Becozweakforcesofattractionbetweenmolecules)
3. Insolubleinwater, Solubleinorganicsolvents!
#IonicCompound
1. Conductelectricityismolten,Aqueousstate
Becauseitcontainmovingions
Doesnotconductonsolidasionscannotmove
2. HighMeltingpointMorethan1000oC henceioniccompoundsaregenerallysolidsatroomtemp.
Becauseofstrongforcesofattractionbetweenions
3. Solubleinwater
Ifaquestion(>5m)asksyoutoexplainwhyIoniccompoundshavehighBP, CovalenthasLow
BP,answerinthisformat:
1) Ioniccompoundsconsistentirelyofions.
2) Theoppositechargedionsareheldclosetooneanotherbyverystrongelectrostatic
attraction, knownasionicbonds.
3) Hencelargeamountofenergyneededtobreakionicbonds.thereforehighB.P
4) Covalentcompoundsconsistentirelyofmoleculesastheyareformedbysharingof
electrons.
5) Forcesbetweenmoleculesareveryweak.
6) Onlysmallamountofenergyneededtobreakbinds. thereforelowB.P
Generalnotes:
Electricityconductivitylinkedtopresenceofmovingions
Boilingpointlinkedtoforcesofattractionbetweenmolecules/ions.
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Chapter5Summary
METALS5.1PhysicalPropertiesofMetals
#Metals
1. Goodconductorsofheat/electricity
Containelectronsthatarefreetomovethroughthemetal.
Formakingcookingutensils/ wires
2. HighMp,Bp
Havestrongbondsbetweenatoms,alotofenergyisneededtoweaken&breakbonds.
3. Malleable (Canbepressedintodiff.shapes)
Layers
ofmetals
can
slide
over
each
other
easily
#Alloys Mixtureofmetal+otherelement
Brass=Zinc+Copper
Steel=Iron+Carbon
Note: Alloysareusedbecausetheyarestronger&harderthanpuremetals.
Atomshavedifferentsizes, whichpreventsthemfromslidingovereachother
Personal Tips: Always remember that if you experience doubts, NEVER HESITATE TO ASK!
Asking the teachers is far better than discussing with your classmates!
- If one teacher cant make you understand, try another teacher. Youll surely get one that suits you!
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#5.2ReactivitySeries
1) Potassium
Explosionwithcoldwater ExplosionwithDilutehydrochloricacidMoreReactive
Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Lead
Hydrogen
Copper
Silver
Gold
LeastReactive
2) Sodium
Veryfastreactionwithcoldwater
ExplosionwithHCl
3) Calcium
Fastreactionwithwater
FastreactionwithHCl
4) Magnesium
Veryslowreactionincoldwater
FastreactionwithHCl
5) Zinc
Noreactionwithcoldwater,Burnsinsteam
FastreactioninHCL(heated)
6) Lead
Noreactioninwater
VeryslowreactioninHCl
7) Copper
NRinwater
NRinHCl
8) Silver
NRinwater
NRinHCl
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#5.3ExtractionofMetalsfromOres
Orearockwhichusefulmetalscanbeobtained.
Metalisobtainedfromitsorebychemicalreaction:Extraction
Extractionisdoneinsideafurnace.
*Methodsofextraction
Themethoduseddependsonhowreactiveisthemetals!
VeryReactiveMetals
Electrolysis For:
(Decomposingmetalcompoundwithelectricity) Potassium
Sodium
Calcium
Magnesium
Aluminium
_________________________________________________
ModeratelyReactiveMetals
Heatingmetaloxidewithcoke For:
Zinc
Iron
Lead
_________________________________________________
LowReactivityMetals
Heatingmetalcompoundsinair For:
Copper
Silver
Note: Electrolysisisexpensive, hencealuminumisexpensive.
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#ExtractionofIron
Iron ExtractedfromoreHaematite (Impureiron(III)oxide) intheblastfurnace
Blastfurnacecontains:
1. Ironore2. Coke
3. Limestone
Blastsofhotair(containingoxygen)areblownintothefurnacenearthebottom.
MoltenIron
MoltenSlag
HotairHotair
Ironore,coke,
limestoneWasteGasesWasteGases
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
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#5.4Recycling
RecyclingmetalsCollecting,meltingdownstrapmetalstomakeblocksoffreshmetals
(Formakingnewmetalobjects)
AdvantagesofRecycling:
1. Metaloresinthegroundcanlastlonger.
2. Moneysavedinenergyneededtoextractnewmetalsfromore.
3. Scrapmetalisremovedfromtheenvironment,
preventsland&waterpollutionduetocorrosion.
DisadvantagesofRecycling:
1. Expensivetocollectstrapmetalsfrommanysources
2. Metalfumesproducedinmeltingofscrapmetalscancausepollution.
_____________________________________________________________________________________
#5.5Aluminium
1) Quiteareactivemetal (Higherinreactivityseries)
CorrosionResistant
ThinlayerofAluminiumOxidepreventscorrosion.
(Preventsair,waterfromreachingthemetalunderneath)
Uses:
Food/drinkcontainerCorrosionResistant.
AircraftbodiesLowdensitysothataircraftbodyislight.
OverheadpowercablesGoodelectricalconductor,lessdense
comparedtocopper(Cablecanbelighter)
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#5.6Iron&Steel
Rusting Duetoairandwater reactingwithiron.
Afterreaction,ironbecomesIron(III)Oxide,FeO3
#RustingPrevention
I. BarrierMethod
Useofpaint,grease,oiloranothermetal.eg.tin
II. SacrificialProtection
Coatingironorsteelwithamorereactivemetal.
Eg.
Galvanising Coatingiron/steelwithzinc. (Ironcorrodesinsteadofzinc)
Magnesiumattachedtoironpipelinestoprotectfromrusting.
Iron
Pipeline
Magnesium
InsulatedCoppercable
Personal Tips: To remember Chemistry Facts, write out in a piece of plain paper (NOT FOOLSCAP).. Just repeat writing them out..
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Chapter6Summary
THEPERIODICTABLE6.1TheStructureofthePeriodicTable
1) Elementsarrangedinorderofprotonnumbers.
2) VerticlesColomnsGroups
AllelementsinGroup2have2valenceelectrons
AllelementsinGroup3have3valenceelectrons..etc
3) HorizontalrowPeriod
LeftRight = MetalsNonmetals
AllelementsinPeriod1have1outershellofelectrons
(Eg. Hydrogen:1. Helium:2.)
AllelementsinPeriod2have2outershellsofelectrons eg
(Eg.Lithium:2.1 Oxygen:2.6)
AllelementsinPeriod3have3outershellof...~
(Eg.Magnesium: 2.8.2 Chlorine: 2.8.7)
*NotethatHydrogenisconsideredanonmetal(ForansweringOLevelexaminations)
Elementsinsamegroup:
Samechemicalproperties
Sameno.ofvalenceelectrons
Diffphysicalproperties
Differentempiricalformula
Notethatthechemicalpropertiesofanelementislinkedtotheno.ofvalenceelectrons.
Sobecozelementsinsamegrouphavesameno.ofvalenceelectrons,theywillhavesamechemical
properties.
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#6.2Group1Elements
Group1elementsarecalledAlkalimetals
Becauseitsfromgroup1,ithas1valenceelectron
Andbecauseitsametal,itcanlose1electronandformapositivechargedion:+1(whichismorestable)
Eg. Potassium: 2.8.8.1 Lithium:2.1 Sodium: 2.8.1
Group1elementsareveryreactive!!! (BottomMOREREACTIVEthanTOP)
Theyreactwithcoldwatertoform Alkalinesolutionof Metalhydroxide&Hydrogen
gas.
Soft,Silverymetalswithlowdensityandmeltingpoint(BottomLOWERm.pthanTOP)!!
Examplereactions:
1) Lithium+WaterLithiumHydroxide+HydrogenGas
2Li+ 2H2O 2LiOH + H2
2) Sodium+WaterSodiumHydroxide+HydrogenGas
2Na + 2H2O2NaOH+H2
3) Potassium+WaterPotassiumHydroxide+HydrogenGas
2K + H2O KOH + H
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#6.3Group7Elements
Group7elementsarecalledHalogens
Becauseitsfromgroup7,ithas7valenceelectrons
Andbecauseitsanonmetal,itcangain1electronandformanegativechargedion:1
(whichismorestable)
Eg. Fluorine: 2.7 Chlorine:2.8.7
Group1elementsareveryreactive!!! (BottomLESSREACTIVEthanTOP)
Theyformacidicsolutions
Colouredsubstanceswithlowmeltingpoint(BottomHigherm.pthanTOP)!!
Theyarediatomicmolecules (Eachmoleculecontains2atoms)
Eg. Cl2, Br2, I2,etc
Coloursofelementsbecomedarkerdownthegroup, LiquidSoliddownthegroup
Fluorine: PaleYellow (Gas)
Chlorine: YellowishGreen (Gas)
Bromine: ReddishBrown (Liquid)
Iodine: Black (Solid)
Astatine: Black (Solid)
Morereactiveelementsdisplacelessreactiveelements(Displacemeansreplaceotherlessreactiveelements)
Eg. WhenChlorinereactswithPotassiumIodide,: (DisplacementReaction)
ChlorineismorereactivethanIodide
WhichmeansChlorinehavethepowertokickoffIodide,andreplaceitsposition!
Soafterthereaction,itllbeleftwithPotassiumChlorineANDIodide.
ChemicalEquation:
Cl2+2KII2 + 2KCl
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#6.4 Transition Metals(ForstudentstakingPureChem)
TransitionElementsareallmetals,theydonotbelongtoanygroup
Theyhavehighdensityandmeltingpoint(1500oC)
Actsasgoodcatalysts
Formcolouredcompounds
Theyhavevariablevalencies(donothavefixedno.ofvalenceelectrons)
*AlsonotethatGroup2elementsarecalledAlkalineMetals
*RAYResource2009: Refertotheattachedmodifiedperiodictabletogetamoredetailedviewoftheentirechapter. Thiswillhelpyou
rememberthefactsbetter!
Alternatively,thisresourceisavailableforfreedownloadatrayrevision.webs.com
Below:PreviewofPeriodicTable
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Chapter7Summary
THEENVIRONMENT7.1CompositionofAir
Airisamixtureofgases. 79% Nitrogen
20%Oxygen
1%Othergases(mainlyargon)
AlsocontainsmallamountofCarbonDioxide&watervapour.
7.2UsesofOxygen
1) Oxygenisusedforcombustion.
Combustionmeansburning
Eg.CombustionofCarboninblastfurnacetoproduceCO2
Otherinfo:
2) Oxygententshelpspeopletobreathe
3) Makingsteelbyburningimpuritiestooxidesthenremoved.
4) OxyacetyleneAcetylenegasburninO2,hightemp.meltsteel
5) LimestonerockaformofCalciumCarbonate
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AcidRain
SulphurDioxideandNitrogenDioxidearemaincausesofacidrain.
Killsfishinfreshwaterlakes
Prevented
by
Fitting
motor
vehicles
with
catalytic
converters
toreduce
emissions
of
nitrogenoxides.
GeneralNote: Metalsformbasicoxides, Nonmetalsformacidicoxides.
ThusBothSulphur&NitrogenformAcidicoxidesbecoztheyarebothnonmetals.
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Chapter8Summary
ACID&BASES8.1PropertiesofAcids
CommonAcids:
1. HydrochloricAcid HCl
2. NitricAcid HNO3
3. SulphuricAcid H2SO4
4. EthanoicAcid CH3COOH
Whenanaciddissolveinwater,itproducesHydrogenIons, H+.
Acidturnsbluelitmuspaperred
Acidturnsuniversalindicatorred
pHvaluelessthan7
Rules: (MUSTREMEMBER!)
1) ACID + METAL SALT + HYDROGENGAS(Pleasenotethataciddonotreactwithanymetalsbelowhydrogeninthereactivityseries!!!)
SOwhatImeanbysalt?
Youjustneedtoknowthat Nitrate, Sulfate, Chloride, Carbonate ARE Salts!
Thenameofsaltproducedsimplydependsonwhatacidisused.
SoifyouuseHydrochloricacidtoreactwithametal, itwillformmetalChloride&HydrogenGas.
Eg. IfyouputHydrochloricAcidandSodium, ItformsSodiumChloride &HydrogenGas
Eg. IfyouputSulphuricAcid andZinc, Itforms ZincSulfate &HydrogenGas
2) ACID + BASE SALT + WATER*Mustremember: A baseis MetalOxideor Hydroxide
(Oxidecontains O, Hydroxidecontains OH)
Whichmeansanymetalthat containsan oxideor hydroxideinitsname is a BASE!!
Eg. H2SO4 + CuO CuSO4 + H2OACID BASE SALT WATER
Eg. HCl + NaOH NaCl + H2O
ACID BASE SALT WATER
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3) ACID + CARBONATE SALT + WATER + CARBONDIOXIDEGASNote:AnythingthatcontainsaCO3initsnameisacarbonate.
i.e. MgCO3,CuCO3,etc arecarbonates
Eg. 2HCl + CuCO3 CuCl2 + H2O + CO2ACID CARBONATE SALT WATER CARBONDIOXIDE
Eg. H2SO4 + MgCO3 MgSO4 + H2O + CO2ACID CARBONATE SALT WATER CARBONDIOXIDE
*Extranotes: Beforeyoubalancetheequation,alwayscheckifyouhavewrittenthecorrectformulas.
Eg. CuCl2 notCuCl. Ifyouareunabletobalance,itmustbeduetoincorrectformulas.
Approachteachersforhelponbalancingequationsasthistypeoftopicisbettertaughtverbally.
Again, BE BRAVE! Take the 1st step in faith..
8.2PropertiesofBases
Remember? Basesare MetalOxides orHydroxides, soanythingthatcontainsthis2wordsareBases!
Thereare2typesofBases; SolubleBase & InsolubleBase
Alkali
areSoluble
Bases
Youonlyneedtoremember4alkalis:
1. PotassiumHydroxide
2. SodiumHydroxide NaOH
3. CalciumHydroxide Ca(OH)2
4. Ammonia NH3
Justrememberthe4solubleBasesby PO,CA, SO, NH4
WhenanAlkali(SolubleBase)dissolvesinwater,itproducesHydroxideIons, OH.
AlkaliturnsRedlitmuspaperBlue
Alkaliturnsuniversalindicatorblue
pHvaluemorethan7
*ExtraInfo: Farmersputalkali, CalciumHydroxide,ontothefieldstoneutralizeexcessacids.
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8.3ThepHScale
ThesmallerthepH,themoreacidicisthesolution.(MeanshigherconcentrationofHydrogenIons,H
+)
TheLargerthepH,themorealkalineisthesolution.(Meanshigherconcentrationofhydroxideions, OH
)
Eg. SomethingwithpHvalueof3ismoreacidicthansomethingwithpHvalue9.
pHvalues:
1 6=Acidic
7 = Neutral
8 14=Alkaline
ThepHofasolutioncanbemeasureusing:
1. UniversalIndicator
2. pHmeter
8.4Oxides
OxidesAreCompoundsofoxygenwithotherelements
3TypesofOxides:
1. Acidic
2. Basic
3. Amphoteric
Remember? Metalsformbasicoxides, Nonmetalsformacidicoxides.
Hence AcidicOxides OxidesofNonmetals
BasicOxidesOxidesofmetals
Eg. SO3, CO2, SO2,NO2 are AcidicOxides becoz S,C,Narenonmetals.
Eg. MgO,CuO,CaOareallBasicOxides becoz Mg,Cu,Ca aremetals.
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AcidicOxide+ WaterAcidEg. SO3+H2OH2SO4
Acid +BaseSalt + Water
Rememberthatabasereferstometaloxidesorhydroxides.
Thus BasicOxide(Base)+Acid Salt+Water
Eg. CaO+2HNO3 Ca(NO3)2 +H2O
AmphotericoxidesMetalOxidesthatreactwithbothacid&alkalis toformsalts
ForOLevels,youonlyneedto
memorisethe3AmphotericOxides:
1. AluminiumOxide A2O3
2. ZincOxide ZnO
3. LeadOxide PbO
Personal Tips: You must memorize the Acid+MetalSalt+Hydrogen Gas etc.. A full list of equations summarized from all chapters
is attached with this .zip package. To remember better, photocopy that list, paste it on the wall of your room or restroom - It works!
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8.5SaltPreparation
Personal Tips: This might seem the hardest chapter to you now. But in truth, it interesting and simple to do!
- You MUST Clear Doubts with your teachers regularly, and youll see miracles in your next test results.
First,You
must
memorise
the
secret
method
tosee
ifasalt
issoluble.
(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
Howtouse?Factsoftable:
AllNitratesaresoluble
AllCarbonatesthatarefromgroup1intheperiodictablearesoluble; therestare
insoluble. Eg.PotassiumCarbonateissoluble, BariumCarbonateisinsoluble
AllsulfatesaresolubleexceptBariumSulfate,Cacium~,Lead~.
Eg.Zincsulfateissolublewhile Calciumsulfateisinsoluble
AllChloridesaresolubleexcept SilverChloride,LeadChloride..
Eg.CalciumChlorideissoluble, LeadChlorideisinsoluble
SoisMagnesiumSulfatesoluble?YES
IsSodiumCarbonatesoluble?YES
Youstillneedtoknow1fact: Allgroup1saltsareSOLUBLE!
WhichmeansLithiumCarbonate,PotassiumChloride,etcareconfirmedsolublesincetheyre
fromgroup1ofperiodictable.
Youcanprepare(make)saltsinmanyways,dependingonwhattypeofsaltitis.
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*ImportantNotes:
TitrationMethod(SolubleBase+Acid)
Toprepare
any
salt
that
is
from
Group
1.(Eg.PreparingSodiumSulfate)
1) Add25cmofacidtoaconicalflask
2) Addafewdropsofindicator.(eg.PhenolPhthalein)
3) AddSodiumHydroxideusingaburetteuntilindicatorchangescolour.
4) Repeatexperimentwith25cm3ofSulphuricAcidbutNOindicator!
5) AddsamevolumeofSodiumHydroxide.
6) SodiumSulfateisobtainedbyevaporating&crystalisingthesalt.
______________________________________________________________________________
Precipitation
Method(Soluble+Soluble)
ToprepareanyInsolublesalt.(Eg.PreparingSilverChloride)
1) AddSilverNitratewithSodiumChloride.
2) Filterouttheprecipitate.
3) Washtheresiduewithdistilledwater.
4) Leavetheresiduetodry.
Touseprecipitation,justmakesurethesaltyouwanttomakeisinsoluble.
ThemethodrequiresyoutouseSolublesalt+Solublesaltsousingthetable,justfind2salts
thataresolubleandcontainpartofthename.
______________________________________________________________________________
Forexample,IwanttomakeaninsolublesaltcalledCalciumSulfate.
1st
, IneedtofindCalcium~thatissoluble. AndIalsoknowthat Allnitratesaresoluble
Sothe1stsaltIuseisCalciumNitrate.
Next,Ineedtofindsomethingsulfatethatissoluble. IalsoknowthatallGroup1saltsaresoluble..
SoIcanuseLithiumSulfateasmy2ndsalt.
Byreacting2salts, IllgetwhatIwant, whichisCalciumSulphate!!
Ca(NO3)2+Li2SO4CaSO4+2LiNO3
Whentheyreact,theysimplyjustchangepartners..
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ToprepareSolublesalt,butNOTfromGroup1:
Thereare2ways:
1) Solublesalt+solublesalt
2) SolubleSalt+InsolubleSalt
Eg.ToprepareMagnesiumSulfate:
IuseMagnesiumNitrate&SodiumSulfate(Botharesoluble)
Mg(NO3)2+Na2SO4MgSO4+2NaNO3
Alternatively,IcanalsouseSoluble+Insolubleway.
IuseMagnesiumNitrate&BariumSulfate(1issoluble,otherisnot)
Mg(NO3)2+BaSO4MgSO4+Ba(NO3)2
Soluble Insoluble
Nitrate All -
Sulfate Rest Ba, Ca, Pb
Chloride Rest Ag, Pb
Carbonate Group1 Rest
Rememberingthetable
3rdrow: BakedChickenPastaAtPastamania
1strow: NoSuperChildishChildren
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Chapter9Summary
ChemicalAnalysisChemicalAnalysisisaboutfindingthenameofanunknownsalt bycarryingoutseveral
experiments/tests..
Allsalts
contains
2parts:
Cation
(+ve
charges
ions)
&Anion
(vecharged
ions)
Thequestionusuallyshowstheobservationsoftests, andyouwillhavetofindoutwhatisthesalt
accordingtotheobservation.
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
Pb
2+
W S W I
TheCATIONStableshows thecolourchangesobserved when thesaltisaddedto
SodiumHydroxide,NaOH, or AqueousAmmonia,NH3.
Italsoshowswhetherthesaltissolubleinexcessalkali(NaOH,NH3)
Forexample, Icarryoutanexperimenttofindoutwhatanunknownsaltcontain.
WhenIaddNaOHtothesalt,colourchangestowhite,andwhenIaddexcessofNaOH,
itdissolved (Soluble).
Next, ItriedaddingNH3tothesalt. Thecolouralsochangestowhite,anditisalso
solubleinexcessNH3.
Then,Imatchthetestresultswiththetable. TheunknownsaltcontainsZinc,Zn2+
ColourofObservationSolubleor
Insolubleinexcess
Alkali
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TestingforANIONS:
ANION Testedwith Observations
Chlorine
AgNO3 AgCl
White
Carbonate Acid CO2 CarbonDioxide(TurnLimewaterchalky)
Sulphate Ba(NO3) BaSO4 WhiteNitrate Al,NaOH NH3 Ammonia
(Turnredlitmusblue)
Iodide Pb(NO3)2 PbI2 YellowEg.
Itested
salt
xwith
Silver
Nitrate
AgNO3,
awhite
precipitate
is
formed.
This
meansthatsaltxcontainsChlorine.. (ThewhiteprecipitateisAgCl)
TestforGASES:
Ammonia UsedamplitmusPaper Turnsfromredtoblue
CarbonDioxide UseLimewater Whitepptformed(TurnsChalky)
Chlorine UseDampbluelitmuspaper BleachesLitmuspaper(LitmusTurnscolourless)
Hydrogen UseBurningSplint 'Pop'SoundHeard
Oxygen UseGlowingSplint GlowsBrighterorBurstintoflames
SulphurDioxide PlaceadropofPotassiumDichromate(VI)onFilterpaper OrangeDichromateturnsgreen.
ImportantTips: YouMUSTmemorisethe3powerfultablesabove! Theyregoingtohelpyoumemorisethingssoeasily. Youwontbeableto
findanyeasystuffslikethatinyourtextbook! Soitsyourchoicetouseitorleaveit.Whateveryouchooseisright.
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Chapter10Summary
MOLECONCEPT10.1CountingAtoms:TheMole
*This chapter is better to be taught verbally by your teachers as its not easy to explain in words.Thus, approach teachers when in any doubt!
Memorise this 4 IMPORTANT Formulas:
Somefacts:
1. 1Mole=6x1023particles
2. MolarMass Massof1moleofanysubstance
3. RelativeAtomicmass=Molarmass, thediff.isthatMolarmasshasagramsonit.
32
4. Eg.Sulfur:S16 hasamolarmassof32g.Whichalsomeansitcontain32gpermole.
#10.2MolarVolumeofGases
1Moleofanygas,hasthesamevolumeof 24dm3atroomconditions (25oC,1Atmosphere)
Eg.Ammonia NH3 MolarMass=17g
CarbonDioxide CO2MolarMass=44g
1dm3=1000cm3
Massof
Sample
No.of
MoleMolar
Mass
No.of
Particles
No.of
Mole 6x1023
Volumeof
Gas
No.of
Mole 24dm3
Mole
ConcentrationVolume
24dm
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#10.3Concentrationofsolutions
+ SOLID LIQUID
Solute Solvent Solution
Dissolvein ToForm
Concentrationismeasuredinmol/dm3
#10.4MolecularFormula
The Molecular formula shows the actual number of each type of atoms present
in a compound
Tofindthemolecularformulaofacompound,youneed:
1. EmpiricalFormulaofcompound2. Relativemolecularmass
Forexample:
Therelativemolecularmassofacompoundis62
Theempiricalformulaofthecompoundis(COH3)
1) Calculate:(COH3)=12+16+3=312) Writethestatement: 62=n(31)3) Findn: n=62/31=24) n=25) Add2intotheformula: (COH3)2=C2O2H6 (ans.)
#10.5EmpiricalFormula
Empirical Formula the simplest formula of a compound which shows the ratio
between the atoms of each element.
Findingtheempiricalformulaisaboutfindingtheno.ofmolesofbothitems,dendevidetheir
valueswiththesmallervalue.
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Eg. Asubstancecontain80%Copper, 20%Sulfur
Findtheempiricalformula.
1)Findtheno.ofmoleofbothitems!
no.ofmoleofCopper:80/64=1.25mol
no.ofmoleofSulfur:20/32=0.625mol
2)Youcompare2values;0.625isasmallervalueright?3)So,devidebothvalueswith0.625:
1.25
/0.625=20.625
/0.625=1
4)Den,youputthenumbersinthisform: Cu2S (ans)
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Chapter12Summary
OXIDATION&REDUCTIONMustmemorise:
Oxidation
1. GainOxygen
2. LossHydrogen
3. Losselectrons
4. Increaseinoxidationstate
Reduction
1. Gainhydrogen
2.
Gainelectron
3. LossOxygen
4. Decreaseinoxidationstate
Eg. PbO+MgPb+MgO
Generalnotes:
A
substance
that
causes
something
tobe
oxidised
isan
oxidising
agent.
Asubstancethatcausessomethingtobereducedisanreducingagent.
Anoxidisingagentitselfisbeingreducedinthereaction
Anreducingagentitselfisbeingoxidisedinthereaction
*RedoxreactionAreactioninwhichOxidationandreductiontakesplace.
OxidisingAgent
(CausesMgtobe
oxidised)
Reduced(Itloses
oxygento
becomePb)
Oxidisedbecause
itgainsoxygento
becomeMgO
Reducingagent(Causes
Pbotobereduced)
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#Oxidation&ReductionaschangesinOxidationstate
Remember:
IncreaseinOxidationstateOxidation
Eg.MgMg2+
(Oxidationstategainsfrom0to+2) Mgisoxidised.
DecreaseinOxidationstateReduction
Eg.ClCl
(Oxidationstatedecreasesfrom0to 1) Clisreduced.
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Chapter13Summary
RATEOFREACTIONS
Slowreactions:
Rottingapieceofwoodintheground
Rustingofasteelfence
Fastreactions:
Dynamiteexploding
Burningapieceofmagnesiuminair
Notes:
1. Reactionstakesplacewhenparticlescollide.
2. Mostcollisionsdonotproduceareactionbecausecollidingparticlesneedaminimum
energytoreactwhentheycollide.
ThisiscalledActivationEnergy
#Factorsaffectingspeedofreaction(ParticlesTheory)
1) Concentrationofsolution
Thehighertheconcentrationofsolution,thefastertherateofreaction.
Becausetheparticlesareclosertogether sotheycollide morefrequentlyandsothere
weremorefrequentreactions.
Note:Onlyappliestoreactionsofsolutions.
2) Pressure
Thehigherthepressure,thhigheristherateofreaction.
Becausetheparticlesaresqueezedclosertogether,sotheycollidemorefrequently
andsothereweremorefrequentreactions.
Note:Onlyappliestoreactionsofgases.
3) Particlesizeofsolid
Thesmallertheparticlesize,thehighertherateofreaction.
Becausethetotalsurfaceareaofthesolidincreasessoreactingparticlesofliquidand
gasescollidemorefrequentlywiththesurfaceandsotherearemorefrequentreactions.
Note:Onlyappliestoreactionsofsolids.
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4) Temperature Thehigherthetemperature,thefastertherateofreaction.
Becauseathighertemperature,theparticleshavegreaterkineticenergy,sotheyreact
moreoftenwhentheycollide.
#Chapter14Heatchangesinreactions
1) Exothermic ve Energy/HeatReleased Solution/TesttubeBecomeshot BondForming H= ve (NegativeValue) Eg.AllcombustionreactionlikeburningMagnesiuminair/Reactionofacidwithalkalis
Why solution turns hot when heat is given out?
Heatisreleasedfromthesolutiontoyourhandssoyoufeelthetesttubeishot.
ReactionDiagram:
TemperatureDiagram:
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2) Endothermic+ve Energy/HeatAbsorbed Solutionturnscold BondBreaking
Eg.Freezing
of
ice
H=+ve (PositiveValue)Why solution turns cold when heat is taken in?
Theheatinyourhandsisabsorbedsoyou'llfeeltesttubebecomingcold.
ReactionDiagram:
TemperatureDiagram:
*Mostreactions
are
exothermic
as
they
make
the
test
tube
turn
hot.
Info:
Energyistakenintobreakbonds.
Energyisgivenoutforbondforming.
HreferstoDeltaH
Histheamountofheatenergytakenin/givenoutduringachemicalreaction.
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Chapter15Summary
FUELS
#15.1FossilFuels
1) Petroleum&NaturalGasarethe2mainfossilfuels.
Fossilfuelswereproducedfromplantandanimalremains(Longago)
2) Petroleum Astickyblackliquidandamixtureofhydrocarbons.
3) NaturalGasconsistmainlyofmethane
#15.2FractionalDistillationofPetroleum
Petroleumisseparatedtodifferentfractionsbyfractionaldistillation.
Seperationcantakeplacebecausepetroleumisamixtureofsubstanceswithdifferentboilingpoints.
ImportantProcess:
1. Thepetroleumisheatedinafurnacetovapouriseit.
2. Thevapourcondensestoliquidatdifferentheightsupthefractionatingcolomn,where
itcomesoutasdifferentfractions.
3. Afractionis mixtureofhydrocarbonwitharangeofboilingpoints.
Thehydrocarbonsarealkanes.
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#15.2(b)FractionatingColomn
3575oC
70170
o
C
170250oC
250340oC
350500OC
PetroleumGases
(Propane,Butane,etc)TomakeCylinderGasforcooking
Petrol(Gasoline)Fuelsforcars
Naptha(MakingChemicals)
Kerosene(Paraffin)Fuelforjet
aircraft
Diesel Fuelfordieselenginesin
buses
LubricatingOilsmaking
Lubricants,Polishes,wax
BitumenSurfacingRoads
Petroleum
Lower
Boilingpoint
(Below25oC)
Smaller
molecules
HigherBoilingpoint
(Above500oC)
Largermolecules
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Youmustremembertheorderoffractionsandtheiruses!
2) Petrole(Paraffin)
n
1) Petroleum3) Naptha4) Kerosen5) Diesel6) LubricatingOil7) Bitume
#CombustionofFossilFuels
airproducewaterandcarbondioxide(Completecombustion)
*Carbonmonoxideandsootwillalsobeproducedifnotenoughair
(Incompletecombustion)
1) Hydrocarbonburnsin
CH4 + CO2 CO2 + 2H2O
2)
#15.2(c)
Petrolanddieselareneededasfuelsforvehicles
Petroleumdoesnothaveenoughofthem. HenceCrackingisdone
Alkane
(Hydrocarbon)
Air(Oxygen)Mainlycarbon
Areactioninwhichbighydrocarbonmoleculesarebrokendownintosmaller
moleculesbyheat.
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Chapter16Summary
HYDROCARBONS
16.1Alkanes
1) Alkanesaresaturatedhydrocarbons (Nomoreatomscanbeaddedtotheirstructure)
2) Generalformula:C H
mallerMolecules(LessCarbonAtoms)
LowerB.p
e C H
HigherB.p (MoreCarbon
omologousseries
A set of organic compounds in which the formula of each one differs
from the previous one by an extra CH2- group of atoms.
embersinaHomologousSerieshave:
n 2n+ 2
S
1. Methane CH4
2. Ethan 2 63. Propane C3H8
4. Butane C4H10
5. Pentane C5H12
6. Hexane C6H14
LargerMolecules
atoms)
H
M
.OH, COOH)
Samechemicalreactions
Samefunctionalgroup(Eg
Samegeneralformula
DifferentPhysicalProperties!
#ReactionsofAlkanes
AlkanesreactwithChlorineinsubstitutionreaction(Slowreaction,requireslight)
Note:AlkanescanonlyundergocombustionreactionsandSubstitutionreactionwithchlorine!
Otherwise, Alkanesisunreactive.
GAS
Liquid
Eachcarbonatomforms4bonds.
Boilingpointincreasesasmoleculesgetlarger
Wh higherb.p?
y
Intermolecularforcesofattractionbetween
esasmoleculesbecomelarger.moleculesincreas
Homologousseriesof
Alkanes
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16.2Alkenes
1) Alkenesareunsaturatedhydrocarbons (Theycanreactwithmanysubstancesinadditionreactions)
forular: CnH2n) AllalkenescontainC=Cdoublebonds
C2H4
. Propene C3H6
atoms)
2) General3
SmallerMolecules(LessCarbonAtoms)
LowerB.p
7. Methene CH2
8. Ethene
9
10.Butene C4H8
11.Pentene C5H
10
12.Hexene C6H12
LargerMolecules
HigherB.p (MoreCarbon
#ReactionsofAlkenes
1) Alkenesburninair(Combustion)ProduceCarbonDioxide&Water
2 4 2 2+2H2O
uced!
C H +3O 2CO
Ifincompletecombustion,Carbon(Soot)andcarbonmonoxidewillbeprod
*Additionreaction
C=Cdoublebondsarebroken,extraatomsareadded
2H4+Br2C2H4Br2
Alkenes
colourisesifAlkeneispresent)
thatthecolourcanonlybepresentif
remainssingle(Notreacted).
Ifitformsacompound,thecolourwilldisappear.Henceafterthereaction,orangebromine
2) AdditionofBromine
C
Thisreactionisusedtotestfor
(Orangebrominesolutionde
Info: BromineisfromGroup7,soithascolour.Note
Bromine
turnscolourless.
GAS
Homologousseries
ofAlkenes
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3) AdditionofWater
Alkene+SteamAlcohol(RequirePhosporicAcidascatalyst,hightemperature&pressure)
lkene+HydrogenAlkane
4) AdditionofHydrogen(NickelCatalystisneeded)
A
Thisreactionisusedtochangevegetableoiltomagarine.
16.3CrackingofAlkanes
CrackingA reaction in which big hydrogen molecules are broken into smaller molecules
1smallalkanemolecule
1alkenemolecule
1) Alkanes
trolforvehicles
) Hydrogen
by heat.
Donebypressingbigalkanemoleculesoverasolidcatalystathightemperature Products:
*Crackingofalkanesisusedtoproduce:
2) Morepe
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Chapter17Summary
ALCOHOLSANDORGANICACIDS17.1Alcohols
1. AlcoholsareorganiccompoundscontainingOHgroupofatoms.2. GeneralFormula:C H OH
Smaller olecules
LowerB.p
anol CH3OH
Ethanol C H OH
HigherB.p
dsofMakingEthanol:
Ethanol
n 2n+ 1
M
1. Meth
2. 2 5
3. Propanol C H OH3 7
4. Butanol C H OH4 9
LargerMolecules
#Metho
Method1:
Ethene+Steam (Alkene) (Alcohol)
Cottonwooltopreventlossof
liquid,allowsescapeofgas(CO2)
ConicalFlask
Warmwater
(37oC)
AqueousGlucose
& Yeast
Allalcoholsareliquids!
HomologousseriesofAlcohol
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Method2
Fermentationofglucosewithyeast.
Theenzy toethanolmesinyeastchangeglucosein andCarbonDioxide
Reactionisbestat37oC
(Ifhighertemp,enzymestructurewillbedamaged, nolongeractsascatalyst!)
Productsoffermentation:
DilutesolutionofethanolPureethanolisobtainedbyfractionaldistillation.
#UsesofEthanol:
1. Solvents(Eg.Perfumes)
2. Alcoholicdrinks(Beer/wine)
3. ars)Fuel(Petrolforc
#Reactions
1) AlcoholburninairCarbonDioxide+Water
ofAlcohol
toProduce
organicacids
H OH+ O CH3COOH+H2O
(Lose2hydrogen,Gain1Oxygen=Oxidation!)
ctsascatalysttothereaction.
Eg. Ethanol+OxygenCarbonDioxide+Water
2) Alcoholsareoxidisedto
Eg.Ethanol+OxygenEthanoicAcid+Water
C2 5 2
Bacteriainaira
ConditionsforFermentation:
37oC
Enzymesinyeast
NoOxygenpresent
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#17.2CarboxylicAcids
1. CarboxylicAcidsOrganiccompoundsco
2. GeneralFormula:CnH2n+1CO2H
ntainingCO2Hgroupofatoms.
kingformula:
CnH2nO2onfusingformoststudents! ThenewformulaisproventoworkonallOlevel questions! NoProbs!)
SmallerMolecules
Lowe B.p
13. ethanoicAcid C1H2O2
14. thanoicAcid C2H4O2
15. ropanoicAcid C3H6O2
16. utanoicAcid C4H8O2
LargerMolecules
High
*Tip:
Youshould
use
this
alternate
wor
(TheoriginalformulaCnH2n+1CO2Hmakesitveryc
r
M
E
P
B
erB.p
#Acid+AlcoholEster+Water
mixture
littleconcentratedSulphuricAcidactsascatalyst.
Ethanoate.(Ester)
Reactionsof
Carboxylic
Acids
Boilthe
A
Eg.EthanoicAcid+Ethanol Ethyl
#UsesofEsters:
1. Solvents
2. Flavouringinfood
Liquid
Formulasgeneratedusing
thisnewformula:
CnH2nO2
HomologousseriesofOrganicAcids
Estershave
sweetsmell
Reactionofmaking
n
Estersiscalled
Esterificatio
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Chapter18Summary
MACROMOLECULES
ger tested in Science (Chemistry) new 20 lla
r sendmeanemailtorequest
forsummarizednotesonthistopic. Theupdatednoteswillthenbemadeavailableinthe
extversionofthisnotesseries.
ThePeriodicTableandFullChemistryequationsisattachedwiththis.zippackage.
isrecommendedthatyouphotocopyextrasandpastethemontowallsofyourroomorevenwashrooms! Itllhelpyouto
i t k t ? S d il C ti ill b d ithi 2 d
(Topic is skipped as it is no lon 08 sy
syllabus,
bus)
Ifyouretakingpurescienceandthistopicisinyou
n
It
remember!
F d