Section5:MatterThefollowingmapsthevideosinthissectiontotheTexasEssentialKnowledgeandSkillsforScienceTAC§112.35(c).5.01Matter

• Chemistry(4)(C)• Chemistry(4)(D)

5.02PropertiesofMatter

• Chemistry(4)(A)• Chemistry(4)(B)

5.03Dalton’sAtomicTheoryofMatter

• Chemistry(6)(A)5.04StructureoftheNuclearAtom

• Chemistry(6)(A)5.05ShorthandNotationandIsotopes

• N/A5.06CalculatingAtomicMass

• Chemistry(6)(D)5.07ThePeriodicTable

• Chemistry(5)(A)5.08BondinginElements

• Chemistry(7)(D)5.09NamingIons

• Chemistry(7)(A)• Chemistry(7)(B)

5.10NamingIonicCompounds

• Chemistry(7)(A)• Chemistry(7)(B)

5.11NamingCovalentCompounds

• Chemistry(7)(A)• Chemistry(7)(B)

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5.12NamingAcidsandBases• Chemistry(7)(A)• Chemistry(7)(B)

Note:Unlessstatedotherwise,anysampledataisfictitiousandusedsolelyforthepurposeofinstruction.

SafetyNote:Anychemicalsmentionedinthesevideosarepotentiallyharmfulandshouldbehandledwiththeappropriatesafetyprecautions.

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5.01

Matter

Matterisanythingthatoccupiesspaceandhasmass.

• Themassofanobjectisameasureoftheamountofmattertheobjectcontains.

• Thevolumeofanobjectisameasureoftheamountofspacetheobjectoccupies.

Matterhasthreestates:

• Asolidisaformofmatterthathasafixedshapeandvolume,whichmakesitalmostincompressible.

• Aliquidisaformofmatterthathasavariableshapewithafixedvolume.Liquidsarealmostincompressible,buttheytendtoexpandslightlywhenheated.

• Agasisaformofmatterthattakesboththeshapeandthevolumeofitscontainer.

o Gasparticlesaremuchfartherawayfromeachotherthantheparticlesinaliquid.Thisspacebetweentheparticlesiswhatmakesgasescompressible.

o Vapordescribesthegaseousstateofasubstancethatisgenerallyaliquidorsolidatroomtemperature.

1. Matterintheliquidstateis__________andhasa__________shape.A. incompressible;fixedB. compressible;variableC. incompressible;variableD. compressible;fixed

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CompositionofMatter

• Matterthathasauniformanddefinitecompositioniscalledapuresubstance.

o Anelementisthesimplestformofmatterthathasauniquesetofproperties.

o Acompoundisasubstancethatcontainstwoormoreelementschemicallycombinedinafixedproportion.

• Asubstancecomposedoftwoormoredifferenttypesofatomsormoleculesthatcanbecombinedinvariableproportionsisamixture.

o Amixtureinwhichthecompositionisnotuniformthroughoutisaheterogeneousmixture.

o Amixtureinwhichthecompositionisuniformthroughoutisahomogeneousmixture.

o Asolutionisanothernameforahomogeneousmixture.

TechniquesforSeparatingMixtures

• Infiltration,weseparateasolidandaliquidbypouringthemixturethroughafilterthatallowstheliquidtopass,butnotthesolid.

• Indistillation,weseparatemiscibleliquids(forexample,liquidsthatmixtogetherequallyinallproportions)byboilingofftheonewithalowerboilingpoint.

2. Whichofthefollowingis/aretrue?i. Airisaheterogeneousmixture.ii. Contactlenssolutionisahomogeneousmixture.iii. Chromeisanelement.iv. Magnesiumisanelement.

A. iandiiB. iiandiiiC. ivonlyD. iiandiv

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5.02

PropertiesofMatter

Physicalproperty–Aqualityorconditionofasubstancethatcanbeobservedormeasuredwithoutchangingthesubstance’scomposition

• Anextensivepropertydependsontheamountofmatterinasample.

o Mass

o Volume

• Anintensivepropertydependsonthetypeofmatterinasample,nottheamount.

o Absorbency

o Density

Aphysicalchangeoccurswhenthereisachangeinthestateofthesubstanceandnotthecompositionofthematerial.Physicalchangesareeitherreversibleorirreversible.

• Meltingiceisareversiblephysicalchange.

• Crackinganeggisanirreversiblephysicalchange.

Chemicalproperty–Apropertythatasubstancedisplaysonlybychangingitscompositionviaachemicalchange

Achemicalchangeisachangethatproducesmatterwithadifferentcompositionfromtheoriginalmatter.

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1. Identifyeachofthefollowingaseitherachemicalorphysicalchange.i. Hammeringcopper(Cu)intowire:_______________

ii. Rustformingonametalbench:_______________

iii. Makingasolidhotenoughtogostraighttothegasphase:_______________

iv. Hydrogengasandoxygengascombiningtomakewater:_______________

2. Fourimportantpropertiesofaninorganiccompoundare(i)meltingpoint,(ii)corrosiveness,(iii)length,and(iv)reactivitywithacids.Whichchoicebelowcorrectlyclassifiesthesepropertiesasextensivephysical(EP),intensivephysical(IP),orchemical(C)?A. i=EP,ii=C,iii=IP,iv=CB. i=IP,ii=IP,iii=EP,iv=CC. i=C,ii=C,iii=EP,iv=CD. i=IP,ii=C,iii=EP,iv=C

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5.03

Dalton’sAtomicTheoryofMatter

TheEnglishchemistJohnDalton(1766–1844)madeconclusionsaboutthenatureofmatterthatbecameknownasDalton’satomictheory,orDalton’spostulates.

1. Allmatterismadeofatoms.Atomsareindivisibleandindestructible.

2. Allatomsofagivenelementareidenticalbothinmassandinchemicalproperties.Theatomsofanyoneelementaredifferentfromthoseofanyotherelement.

3. Atomscombineinsimple,fixed,whole-numberratiostoformcompounds.

4. Chemicalreactionsoccurwhenatomsareseparatedfromeachother,joined,orrearrangedinadifferentcombination.Atomsofoneelement,however,areneverchangedintoatomsofanotherelementthroughachemicalreaction.

Dalton’satomictheoryledtothreelawsthathelpedexplaincompoundformationandchemicalreactions.

• Lawofdefiniteproportions–Samplesofanychemicalcompoundmaintainthesameproportionsoftheirconstituentelements.

• Lawofmultipleproportions–Wheneverthesametwoelementscombinetoformmorethanonecompound,thedifferentmassesofoneelementthatcombinewiththesamemassoftheotherelementareintheratioofsmallwholenumbers.

• Lawofconservationofmass–Inachemicalprocess,atomscannotbecreated,destroyed,orchanged—onlyrearrangedintodifferentcombinations.

1. WhichofthefollowingstatementsisnotapartofJohnDalton’satomictheory?A. Allatomsofagivenelementhavethesamemassandotherpropertiesthatdistinguish

themfromtheotherelements.B. Atomscombineinsimple,whole-numberratiostoformcompounds.C. Theatomhasanucleussurroundedbyelectrons.D. Eachelementiscomposedoftinyindestructibleparticlescalledatoms.

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5.04

StructureoftheNuclearAtom

Dalton’satomictheoryiswidelyacceptedtoday,withoneimportantchange.Wenowknowthatatomscanbedividedintosmallerparticles.Thethreekindsofsubatomicparticlesareelectrons,protons,andneutrons.

• Electronsarenegativelychargedsubatomicparticles.

• Protonsarepositivelychargedsubatomicparticles.

• Neutronsaresubatomicparticleswithnochargebutwithamassnearlyequaltothatofprotons.

Eachelementhasitsownuniqueproperties.However,onanatomicscale,elementsareessentiallythesame.

• Everyatomisanelectricallyneutral,sphericalentity.

• Anatomiscomposedofacentralcoreofprotonsandneutrons,calledthenucleus,thatissurroundedbyelectrons.

• Aneutralatomcontainsequalnumbersofelectronsandprotons,butthisratiochangeswhenatomsbecomeions.

NuclearAtomDiscoveries

In1897,J.J.Thomson(1856–1940)discoveredthefirstsubatomicparticle,thenegativelychargedelectron,withthehelpofamodifiedcathoderaytube.Asaresult,Thomsonproposedthe“plum-puddingmodel”oftheatom.Inthismodel,electronswereevenlydistributedthroughoutanatomthatwasfilleduniformlywithpositivelychargedmaterial.

• Acathoderaytubeconsistsoftwoelectrodessealedinaglasscontainerwithgasatlowpressure.

o Whenavoltageisappliedtothecathode,aglowingbeam,orcathoderay,travelsfromthecathodetotheanode.

o Inhisexperiment,Thomsonplacedapositivelychargedplateononesideofthecathoderayandanegativelychargedplateontheotherside.

o Thecathoderaywasattractedtothepositivelychargedplate.Thomsonhypothesizedthatthecathoderaywasastreamofnegativelychargedparticlesmovingathighspeed.

o Aftertestinghishypothesis,heconcludedthatelectronsareacomponentoftheatomsofallelements.

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Theplum-puddingmodelwasshort-lived.In1911,ErnestRutherford(1871–1937)discoveredapositivelychargedsubatomicparticle,theproton.Heusedthegold-foilexperimenttoprovehisconclusions.

• Thegold-foilexperimentusedanarrowbeamofalphaparticles(i.e.,particleswithadoublepositivecharge)directedataverythinsheetofgoldfoil.

o Mostofthealphaparticleswentstraightthroughthegoldfoilorwereslightlydeflected.

o Asmallfractionofthealphaparticlesbouncedoffthegoldfoilatverylargeangles.

• Rutherfordusedtheresultsofhisgold-foilexperimenttodeterminethattheatomwasmostlyemptyspace,sincemostofthealphaparticlespassedstraightthroughthegoldfoil,butthatithadaverydensenucleus,whichdeflectedsomeofthealphaparticles.

In1932,JamesChadwick(1891–1974)confirmedtheexistenceofanothersubatomicparticle,theneutron.

1. Selectthetruestatementfromthechoicesbelow.A. Thechargeofaprotonisequalinmagnitudebutoppositeinsigntothatofaneutron.B. Thegold-foilexperimentledtothediscoverythateachatomcontainsatiny,positively

charged,massivecentercalledthenucleus.C. Themassofaprotonisclosetothatofanelectron.D. Thegold-foilexperimentledtothediscoveryoftheelectron.

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5.05

ShorthandNotationandIsotopes

ShorthandNotation

Elementsaredifferentfromoneanotherbecausetheycontaindifferentnumbersofprotons.Anelement’satomicnumberisthenumberofprotonsinthenucleusofanatomofthatelement.

Mostofanatom’smassisconcentratedinthenucleus.Themassdependsonthenumberofprotonsandelectrons.Thetotalnumberofprotonsandneutronsinanatomiscalledthemassnumber.

Thecompositionofanyatomcanberepresentedinshorthandnotationusingthemassnumberandtheatomicnumber.

!"#

Intheexampleabove,Xistheelementsymbol,Aisthemassnumber,andZistheatomicnumber.

Isotopes

Anisotopeisavariationofanelementthathasthesamenumberofprotonsandelectronsbutadifferentnumberofneutrons.

Isotopeshavevaryingnumbersofneutrons,whichmeanstheyhavedifferentmassnumbers.14Nand15Narebothisotopesofnitrogenbecausetheyhavethesameatomicnumberbutdifferentmassnumbers.

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1. Completethefollowingtable:

!"# AtomicNumber NumberofNeutrons

$%&'('

45 59

2. Howmanyprotons(p+1),neutrons(n0),andelectrons(e-1)doestheisotope55Mnhave?A. 30p+1,25n0,25e-1B. 24p+1,33n0,22e-1C. 25p+1,30n0,25e-1D. 25p+1,25n0,30e-1

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5.06

CalculatingAtomicMass

Calculatingthemassofelementsisdifficultbecausetheirmassesareverysmall.

RelativeMassesofSubatomicParticles

Themassofanatomismeasuredfromthenucleus.

• Protonsandneutronshaveapproximatelythesamemassof1atomicmassunit(amu).1amuequals1.67×10-24g.

• Electronshaverelativelynomass—about0.00055amuor9.109×10-28g.

Chemistshavedevisedasystemtocomparerelativemassesofatomsusingcarbon-12asareferenceisotope.Carbonhasbeenassignedamassofexactly12atomicmassunits.Anatomicmassunitisdefinedas1/12ofthemassofacarbon-12atom.

Sincemostofthemassofanatomisinthenucleus,therelativesystemabovewouldseemtoindicatethattheatomicmassofanelementshouldbeawholenumber,butthisisnotusuallythecase.

Innature,mostelementsoccurasamixtureoftwoormoreisotopes.Theatomicmass,sometimescalledtheaverageatomicmass,ofanelementisaweightedaveragemassoftheatomsinanaturallyoccurringsampleoftheelement.

Tocalculatetheatomicmassofanelement,multiplythemassofeachisotopebyitsnaturalabundance,expressedasadecimal,andthenaddtheproducts.

)*+,-.0122 = 15672+*+8%0122 91*:;1<)=:>?1>.%+ 2BC72+*+8%0122 91*:;1<)=:>?1>.% …

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1. ElementZhasthreeisotopes:Z-31,Z-32,andZ-29.Z-29hasamassof28.98amuandis24.44%abundantinnature.Z-32hasamassof32.12amuandis32.65%abundantinnature.Z-31hasamassof31.23amu.CalculatetheatomicmassofelementZ.

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5.07

ThePeriodicTable

Elementsarethefundamentalbuildingblocksthatmakeupallmatter.

• Theperiodictableisacompilationofallthediscoveredelements.

o Therowsinaperiodictablearereferredtoasperiods.

o Columnsoftheperiodictablearecalledgroups.

• Scientistshavediscoveredover116elements.Eachelementhasitsownuniquechemicalandphysicalproperties.

• Earlychemistsusedthechemicalandphysicalpropertiesofelementstosortthemintogroups.

Inthemid-19thcentury,theRussianchemistDmitriMendeleevnoticedthatcertaingroupsofelementshadsimilarproperties.Mendeleevproposedatablethatarrangedelementsperiodically—thatis,insetswithrepeatingpatterns—inorderofincreasingatomicmass.

Inthemodernperiodictable,elementsarearrangedinorderofincreasingatomicnumberbecausetherewereinconsistencieswithMendeleev’speriodictable.Whenelementsarearrangedinorderofincreasingatomicnumber,movinglefttorightacrossaperiod,theelementshavedifferentchemicalandphysicalproperties.However,thepatternofpropertieswithinaperiodrepeatsasyoumovefromoneperiodtothenext.Thisisreferredtoastheperiodiclaw.

BroadClassesofElements

• Metalsaregenerallygoodconductorsofheatandelectriccurrent.Mostmetalshaveahighlusterandareductileandmalleable.

• Nonmetalsarepoorconductorsofheatandelectriccurrent.Mostnonmetalsarebrittle,butingeneral,physicalpropertiesvarymoreamongnonmetalsthanamongmetals.

• Metalloidshavepropertiesofbothmetalsandnonmetals.Thebehaviorofmetalloidsdependsontheconditions.

1. Classifyeachofthefollowingaseitherametal(M)oranonmetal(N).

i.Bromine(Br) ii.Cobalt(Co) iii.Boron(B) iv.Potassium(K)

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ClassifyingElementsinthePeriodicTable

Becauseoftheperiodiclaw,elementsthathavesimilarpropertiesendupinthesamecolumnintheperiodictable.Thesecolumnshavespecialnames,listedbelow,becauseofthesimilarityofthechemicalpropertiesofthoseelementswithinthecolumn.

• Elementsingroups1Athrough7Aarecalledrepresentativeelementsbecausetheydisplayawiderangeofchemicalandphysicalproperties.

• Themetallicelementsingroups1Athrough7Aoftheperiodictablearecalledmaingroupmetals.

• TheelementsingroupBarecalledtransitionelements.

o ThetransitionmetalsarethegroupBelementsthatareusuallydisplayedinthemainbodyofaperiodictable.Theseincludecopper,silver,andiron.

o TheinnertransitionmetalsarethegroupBelementsthatappearbelowthemainbodyoftheperiodictable.Theseincludeuraniumandplutonium.

Group Name Elements Properties

1A AlkaliMetalsLi,Na,K,Rb,Cs,

andFrSolidsatroomtemperatureandreactviolently

withwater

2AAlkalineEarth

MetalsBe,Mg,Ca,Sr,Ba,

andRaSolidsatroomtemperatureandreact

vigorouslywithoxygen

7A Halogens F,Cl,Br,I,andAtMostlygasesatroomtemperatureandform

saltswhenbondedtoametal

8A NobleGasesHe,Ne,Ar,Kr,Xe,

andRnInertmonatomicgasesatroomtemperature

2. Whichofthefollowingelementsbelongtothealkalineearthmetals?A. F,Cl,Br,I,AtB. He,Ne,Ar,Kr,Xe,RnC. Li,Na,K,Rb,Cs,FrD. Be,Mg,Ca,Sr,Ba,Ra

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5.08

BondinginElements

Elementsbondtoformcompoundswhentheirouterelectronsinteract.Thebondingbetweenthethreebroadclassesofelementsoccursinthreegeneralways.

1. Whenametaldonatesitsouterelectronstoanonmetal,thiscreatesanionicbond.

• Theresultingcompoundiscalledanioniccompound.

• Themetalbecomesapositiveion(cation)andthenonmetalbecomesanegativeion(anion).

o Acationisproducedwhenanatomlosesoneormoreouterelectrons.

o Ananionisproducedwhenanatomgainsoneormoreouterelectrons.

• Althoughtheyarecomposedofions,ioniccompoundsareelectricallyneutral.

• Anioniccompoundisheldtogetherbytheelectrostaticforcesbetweentheoppositelychargedcationsandanions,whichattractoneanother.

• Aformulaunitisthelowestwhole-numberratioofionsinanioniccompound.

2. Whenanatomsharesitsouterelectronswithanotheratom’souterelectrons,thiscreatesacovalentbond.

• Amoleculeisaneutralgroupofatomsjoinedtogetherbycovalentbonds.

• Adiatomicmoleculeisamoleculethatcontainstwoatoms.

• Acompoundcomposedofmoleculesiscalledamolecularcompound.

3. Metalsbondinaspecialwaybecausetheirouterelectronsaremobileanddriftfreelyfromonepartofthemetaltoanother.

• Thiscreatesa“sea”ofelectronsthatarenottieddowntoanyatom.

• Metallicbondsaretheforcesofattractionbetweenthefree-floatingouterelectronsandthepositivelychargedmetalions.

Metallicbondingexplainsmanyofthedifferentmetallicpropertiesinametal.

• Ductility–Apropertyofametalthatenablesittobedrawnintoawire

• Malleability–Theabilityofametaltobehammeredorpressedintoshapes

• Electricalconductivity–Apropertythatenablesasubstancetoconductanelectriccurrentthroughtheflowofelectrons

• Thermalconductivity–Apropertythatenablesasubstancetotransferheat

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1. Whichofthefollowingpropertiesofmetalsisnotexplainedbythe“electron-sea”modelofmetallicbonding?A. MalleabilityB. Metallicluster(shine)C. ElectricalconductivityD. ThermalconductivityE. Ductility

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5.09

NamingIons

Ioniccompoundsconsistofpositivelychargedionsandnegativelychargedionscombinedinaproportionsothattheirchargesadduptoanetchargeofzero.

Monatomicion–Asingleatomwithapositiveornegativechargeresultingfromthelossorgain,respectively,ofoneormoreouterelectrons,calledvalenceelectrons

Whenthemetalsofgroups1A,2A,and3Aloseelectrons,theyformcationswithpositivechargesequaltotheirgroupnumber.Thenamesofthecationsarethesameasthenameofthemetal,followedbythewordionorcation.

• Al3+isthealuminumion

• Na+isthesodiumion

Nonmetalstendtogainelectronstoformanions,sothechargeofanonmetallicionisnegative.ThechargeofanyionofagroupAnonmetalisdeterminedbysubtracting8fromthegroupnumber.

• S2-isthesulfurion

• N3-isthenitrogenion

Thenameofananionisnotthesameastheelement’sname.Anionnamesstartwiththestemoftheelementnameandendin-ide.

1. Nametheionsformedbythefollowingelements.i. Barium

ii. Oxygen

iii. Chlorine

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Manyofthetransitionmetals(groups1B–8B)formmultiplecationsthathavedifferentioniccharges.Thechargesofthecationsofmanytransitionmetalionsmustbedeterminedfromthenumberofelectronslost.

Therearetwomethodstonametransitionmetalswithdifferentioniccharges.

• Stocksystem–ARomannumeralinparenthesesafterthenameoftheelementindicatesthenumericalvalueofthecharge.

• Classicalsystem–Oneoftwosuffixes,attachedtotherootoftheLatinnamefortheion,indicateswhethertheionhasahigherorlowerioniccharge.

o Thesuffix-ousisusedtonamethecationwiththelowerofthetwoioniccharges.

o Thesuffix-icisusedtonamethecationwiththehigherofthetwoioniccharges.

Element IonFormula StockName ClassicalName

Chromium Cr2+ chromium(II) chromous

Cr3+ chromium(III) chromic

Copper Cu+ copper(I) cuprous

Cu2+ copper(II) cupric

Iron Fe2+ iron(II) ferrous

Fe3+ iron(III) ferric

Mercury Hg22+ mercury(I) mercurous

Hg2+ mercury(II) mercuric

Tin Sn2+ tin(II) stannous

Sn4+ tin(IV) stannic

2. Howmanyelectronswerelostorgainedtoformtheseions?i. Mn4+

ii. Zn2+

iii. As3-

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Polyatomicion–Anioncomposedofmorethanoneatom,whichbehavesasaunitandcarriesacharge

Namingpolyatomicionsrequiressomememorizationofthenumberofatomsinandtheoverallchargeofeachion.

• ClO-ishypo–chlor–ite.

• ClO2-ischlor–ite.

• ClO3-ischlor–ate.

• ClO4-isper–chlor–ate.

Remembertheionswithan-ateending.Theseionsareverycommoninioniccompoundsandofferasystematicwaytonameotherions.

Somepolyatomicionshavedifferentendingsthatdonotfitthepatternabove:

• CN-isthecyanideanion.

• OH-isthehydroxideanion.

• NH4+istheammoniumcation.

WhentheformulaforapolyatomicionbeginswithH(hydrogen),youcanthinkoftheHasrepresentingahydrogenion(H+)combinedwithanotherpolyatomicion.

• HCO3-ishydrogencarbonate.

• H2PO4-isdihydrogenphosphate.

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Name Formula

ammonium NH4+

hydroxide OH-cyanide CN-nitrate NO3

-ethanoate CH3COO

-orC2H3O2-

chlorate ClO3-

bromate BrO3-

iodate IO3-

sulfate SO42-

hydrogensulfate HSO4-

carbonate CO32-

hydrogencarbonate HCO3-

phosphate PO43-

hydrogenphosphate HPO42-

dihydrogenphosphate H2PO4-

permanganate MnO4-

chromate CrO42-

dichromate Cr2O72-

oxalate C2O42-

silicate SiO32-

3. Writethesymbolorchemicalformula(includingcharge)foreachofthefollowingions.i. Nitriteion

ii. Hydrogensulfiteion

iii. Perbromateion

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5.10

NamingIonicCompounds

Binarycompound–Acompoundcomposedoftwoelements.Binarycompoundscanbeioniccompoundsormolecularcompounds.

Towritetheformulaofabinaryioniccompound,firstwritethesymbolofthecationandthenthatoftheanion.Then,addsubscriptsasneededtobalancethecharges.

Anothermethodisthe“crisscross”method:

• Crossoutthechargeofeachionandmakeitthesubscriptfortheotherion.

• Dropthecharges.

• Theformulaiscorrectbecausetheoverallchargeoftheformulaiszero,andthesubscriptsareexpressedasthelowestwhole-numberratio.

1. Writethechemicalformulasforthecompoundsformedbythefollowingpairsofions.i. Al3+andCl-

ii. Mg2+andSO42-

iii. Cr6+andN3-

2. Writethechemicalformulaforeachofthefollowingioniccompounds.i. Sodiumsulfide

ii. Aluminumphosphate

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TipsforNamingIonicCompounds

• Placethecationnamefirst,followedbytheanionname.

• Ifthemetallicelementinthecompoundhasmorethanonecommonioniccharge,aRomannumeralmustbeincludedinthecationname.

• Whenevermorethanonepolyatomicionisneededtobalancethechargesinanioniccompound,useparenthesestosetoffthepolyatomicionintheformula.

3. Namethefollowingioniccompounds.i. ZnO

ii. Ag2Se

iii. Al2(SO4)3

4. Writechemicalformulasforthefollowingcompounds.i. Sodiumhydrogensulfate

ii. Nickel(II)sulfite

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5.11

NamingMolecularCompounds

Molecularcompounds,orcovalentcompounds,arecomposedofmolecules,notions,soionicchargescannotbeusedtowritetheirformulasortonamethem.

Theprefixesbelowareusedinthenamesofmolecularcompoundstohelpdistinguishcompoundscontainingdifferentnumbersofatoms.Theprefixestellhowmanyatomsofanelementarepresentineachmoleculeofthecompound.

Prefix Number

mono- 1di- 2tri- 3

tetra- 4penta- 5hexa- 6hepta- 7octa- 8nona- 9deca- 10

Tonameamolecularcompound:

1. Writethenamesoftheelementsintheorderlistedintheformula.

2. Useprefixesappropriatelytoindicatethenumberofeachkindofatom.

• Omittheprefix“mono-”ifjustoneatomofthefirstelementispresent.

• Thevowelattheendofaprefixissometimesdroppedwhenthenameoftheelementbeginswithavowel.

3. Endthenameofthesecondelementwiththesuffix-ide.

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1. Namethefollowingmolecularcompounds.i. Cl2O7

ii. SO3

iii. CO

2. Writetheformulasforthesemolecularcompounds.i. Oxygendifluoride

ii. Tetraphosphorousdecoxide

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5.12

NamingAcidsandBasesAnacidisacompoundthatcontainsoneormorehydrogenatomsandproduceshydrogenionswhendissolvedinwater.

Whennaminganacid,considerittobeananionwithasmanyhydrogenionsneededtomakethecompoundelectricallyneutral.ThechemicalformulasofacidsareinthegeneralformHnX,whereXisamonatomicorpolyatomicanionandnisasubscriptindicatingthenumberofhydrogenionsthatarecombinedwiththeanion.

Acidnomenclaturedependsonthesuffixanionhas:

• Iftheanionnameendsin-ide,theacidnamebeginswiththeprefixhydro-.Thisprefixisattachedtothestemoftheanionwiththesuffix-ic,followedbythewordacid.

• Iftheanionnameendsin-ite,theacidnameisthestemoftheanionwiththesuffix-ous,followedbythewordacid.

• Iftheanionnameendsin-ate,theacidnameisthestemoftheanionwiththesuffix-ic,followedbythewordacid.

Whenwritingthechemicalformulaforanacid,usetheruleforwritingthenameoftheacidsinreverse.Besuretobalancetheionicchargesjustasyouwouldforanyioniccompound.

CommonAcids

AnionFormula AnionName AcidName AcidFormula

Br- Bromide Hydrobromicacid HBr

ClO31- Chlorate Chloricacid HClO3

SO32- Sulfite Sulfurousacid H2SO3

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Abaseisgenerallyanioniccompoundthatproduceshydroxideionswhendissolvedinwater.

• Usetherulesfornamingioniccompoundstonamebases.

• Whenwritingthechemicalformulaforabase,writethemetalcationfirst,followedbytheformulaforthehydroxideion.

• Balancetheionicchargesasyouwouldforanyioniccompound.

1. Nameeachacidorbasebelow.

i. HCl

ii. HNO3

iii. Sr(OH)2

iv. CsOH

2. Writeformulasforthefollowingacidsandbases.i. Hydrosulfuricacid

ii. Perchloricacid

iii. Aluminumhydroxide

iv. Iron(II)hydroxide

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