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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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