Chemistry Full v1.5

8/14/2019 Chemistry Full v1.5

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RAYNOTES2009

09

OLevelSc(Chemistry)v1.5EasynotessummarizedforOLevels

Hong Ray Corporations


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Science(Chemistry)Summarizedversion1.5 RAYNotes2009(Hardcopy)

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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1

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

2


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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

2


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2

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.

2


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2

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.

2


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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!

2


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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.

2


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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

3


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3

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.

3


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3

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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3

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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3

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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4

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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4

#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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4

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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4

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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4

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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4

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

3


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4

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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5

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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5

#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

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