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NamingCompoundsTutorialandWorksheet

Sinceweusedifferentmethodsinnamingbinarycovalent(molecular)compoundsandioniccompounds,thefirststepinnamingorwritingtheformulaofacompoundistodeterminewhichofthe2compoundclassesitbelongs.Thiscanbedoneasfollows:

Binary covalent compoundswill containonly two types of non-metal elements.Theremaybemorethanoneofeachelement.ForexampleCO2containsjusttwotypes of elements, carbon and oxygen. We will discuss naming covalentcompoundsthatcontainmorethantwotypesofelements, likeglucoseC6H12O6,inlaterchapters.

Onceitisdeterminedthatthecompoundisionicorcovalent,thestudentcanbeaskedtodoeitherofthefollowing:1)Giventhenameofthecompound,writetheformula.

Or2)Giventheformulaofthecompound,writethename.Inthistutorialwewillreviewtheprocessforachievingthese2objectivesandpracticewithsomeworksheetproblems.First,wewillreviewandpracticehowtowriteformulasforcompoundswhengiventhecompound’sname.Second,wewillreviewandpracticehowtowritethenameofacompoundwhengiventhecompound’sformula.

DetermineiftheCompoundisBinaryCovalent (Molecular)orIonic:Doesthecompoundcontainonly twotypesofnonmetalelements?

Yes

BinaryCovalent(Molecular)Compound

No

IonicCompound

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GiventheNameoftheCompound,WritingFormulasforCompounds

DetermineiftheCompoundisBinaryCovalent(Molecular)orIonic:

Doesthecompoundcontainonlytwotypesofnonmetalelements?

Yes No

BinaryCovalent(Molecular)Compound:

1) Writethesymbolofthefirstelementinthecompound’sname,thenthesymbolofthesecondelementinthecompound’sname.

2) Indicatehowmanyatomsofeachelementthemoleculecontainsusingsubscriptsaftertheatomicsymbol.

• Thenumbersofatomsaregiveninthemolecule’snameinGreekprefixes• NOTE:IfthereisnoGreekprefixin

frontofthefirstelementinthenamethatimpliesthenumberis1.

IonicCompound:1) Writethesymbol/formulaofthefirstion

inthecompound’sname,thenthesymbol/formulaofthesecondioninthecompound’sname.

2) Indicatetheratiooftheionsinthecompoundusingsubscriptsaftereachion.• Theratiooftheionsisdeducedby

balancingthechargesoftheions.• IMPORTANT:Whenthereismore

thanoneofapolyatomicionintheformulaunitweuseparenthesis.ExampleMg(NO3)2

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WritingtheFormulasofIonicCompoundsExample:Writetheformulaforcalciumbromide.

1) Writethesymbol/formulaofthefirstioninthecompound’sname,thenthesymbol/formulaofthesecondioninthecompound’sname.

CaBr2) Indicatetheratiooftheionsinthecompoundusingsubscriptsaftereachion.

• Thisstepinvolvesfillinginthesubscriptsboxesaswedidinthelecture:

CaBr• Theratiooftheionsisdeducedbybalancingthechargesoftheions.

• Thisisdonesothatthetotalchargeinthecrystal,whenlargenumbersofcationsandanionscombine,isequaltozero.

• Wefindtheion’schargefromitspositionontheperiodictableorwelookitupinatableinthecaseofpolyatomicions.

• TransitionmetalwithvaryingchargeswillbewritteninthecompoundnameinRomannumerals.

• First,temporarilywritethechargeofeachionabovetheion’ssymbol.2+1-

CaBr

• Next,placenumbersinthesubscriptssuchthatthetotalchargeofthecompoundiszero.Notethatinthisexample,weneedtwobromideions,eachhasachargeof(1-)tocancelthe(2+)chargeofthecalciumion:• 2(-1)+(+2)=0zerototalcharge.

2+1-

Ca1Br2=CaBr2

• WesawashortcutwaytodothiscalledtheCriss-CrossMethod(seeyourchapter3notes)

2+1-

Ca1Br2=CaBr2

• Note,wedonotleavethechargeswrittenabovethesymbolsinthecompletedformula.

IMPORTANT:Whenthereismorethanoneofapolyatomicionintheformula,weuseparenthesis.

• Notapplicableinthisexamplesincetherearenopolyatomicionsincalciumbromide.

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Examples:WritingtheFormulasofIonicCompounds

Writetheformulaformagnesiumnitrate.1) Writethesymbol/formulaofthefirstioninthecompound’sname,thenthe

symbol/formulaofthesecondioninthecompound’sname.• Whenyouseeapolyatomicion(nitrate),lookuptheformulaandcharge

inthetableofpolyatomicions.

MgNO32) Indicatetheratiooftheionsinthecompoundusingsubscriptsaftereachion.

a. Thisstepinvolvesfillinginthesubscriptsboxesaswedidinthelecture:

MgNO3• Theratiooftheionsisdeducedbybalancingthechargesoftheions.

• Thisisdonesothatthetotalchargeinthecrystal,whenlargenumbersofcationsandanionscombine,isequaltozero.

• Wefindtheion’schargefromitspositionontheperiodictableorwelookitupinatableinthecaseofpolyatomicions.

• TransitionmetalwithvaryingchargeswillbewritteninthecompoundnameinRomannumerals.

• First,temporarilywritethechargeofeachionabovetheion’ssymbol.2+1-

MgNO3

• Next,placenumbersinthesubscriptssuchthatthetotalchargeofthecompoundiszero.Notethatinthisexample,weneedtwonitrateions,eachhasachargeof(1-)tocancelthe(2+)chargeofthemagnesiumion:• 2(-1)+(+2)=0zerototalcharge.

2+1-

Mg1NO32

• WesawashortcutwaytodothiscalledtheCriss-CrossMethod(seeyourchapter3notes)

2+1-

Mg1NO32IMPORTANT:Whenthereismorethanoneofapolyatomicionintheformulaunitweuseparenthesis.Thereare2ionsofnitrateinmagnesiumnitrate

Mg1NO32=Mg(NO3)2Incompoundwherethereisjustoneformulaunitofapolyatomicion,noparenthesisareneeded.Anexampleofthisissodiumnitrate:NaNO3

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Examples:WritingtheFormulasofIonicCompounds

Writetheformulaforiron(II)phosphate.

1) Writethesymbol/formulaofthefirstioninthecompound’sname,thenthesymbol/formulaofthesecondioninthecompound’sname.

• Whenyouseeapolyatomicion(phosphateinthiscase),lookuptheformulaandchargeinthetableofpolyatomicions.

FePO42) Indicatetheratiooftheionsinthecompoundusingsubscriptsaftereachion.

b. Thisstepinvolvesfillinginthesubscriptsboxesaswedidinthelecture:

FePO4• Theratiooftheionsisdeducedbybalancingthechargesoftheions.

• Thisisdonesothatthetotalchargeinthecrystal,whenlargenumbersofcationsandanionscombine,isequaltozero.

• Wefindtheion’schargefromitspositionontheperiodictableorwelookitupinatableinthecaseofpolyatomicions.

• TransitionmetalwithvaryingchargeswillbewritteninthecompoundnameinRomannumerals.• Inthisexample,nowweknowthechargeontheFeionis2+

• First,temporarilywritethechargeofeachionabovetheion’ssymbol.

2+3-

FePO4

• Next,placenumbersinthesubscriptssuchthatthetotalchargeofthecompoundiszero.Notethatinthisexample,weneedtwophosphateions,eachhasachargeof(3-)andthreeFe2+ionstobalancethecharge:• 2(-3)+3(-2)=0zerototalcharge.

2+3-

Fe3PO42

• WesawashortcutwaytodothiscalledtheCriss-CrossMethod(seeyourchapter3notes)

2+3-

Fe3PO42IMPORTANT:Whenthereismorethanoneofapolyatomicionintheformulaunitweuseparenthesis.Thereare2ionsofphosphateiniron(II)phosphate.

Fe3PO42=Fe3(PO4)2

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Examples:WritingtheFormulasofIonicCompoundsWritetheformulaforbariumsulfide.

1) Writethesymbol/formulaofthefirstioninthecompound’sname,thenthesymbol/formulaofthesecondioninthecompound’sname.

BaS2) Indicatetheratiooftheionsinthecompoundusingsubscriptsaftereachion.

• Thisstepinvolvesfillinginthesubscriptsboxesaswedidinthelecture:

BaS• Theratiooftheionsisdeducedbybalancingthechargesoftheions.

• Thisisdonesothatthetotalchargeinthecrystal,whenlargenumbersofcationsandanionscombine,isequaltozero.

• Wefindtheion’schargefromitspositionontheperiodictableorwelookitupinatableinthecaseofpolyatomicions.

• TransitionmetalwithvaryingchargeswillbewritteninthecompoundnameinRomannumerals.

• First,temporarilywritethechargeofeachionabovetheion’ssymbol.2+2-

BaS

• Next,placenumbersinthesubscriptssuchthatthetotalchargeofthecompoundiszero.Notethatinthisexample,weneedonesulfideion,withachargeof(2-)tocancelthe(2+)chargeofthebariumion:• (-2)+(+2)=0zerototalcharge.

2+2-

Ba1S1=BaS

• WesawashortcutwaytodothiscalledtheCriss-CrossMethod(seeyourchapter3notes)

2+2-

Ba2S2=BaS

• Note,thesubscriptsinioniccompoundrepresenttheratioinwhichlargenumbersofanionsandcationscombinetoformtheioniccompounds.Sincewewantthelowestratio:weuse1:1,since2:2=1:1

Ba2S2=BaS

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Writetheformulaforthefollowingioniccompounds:(seenextpageforkey)

sodiumbicarbonate_________________

sodiumfluoride_________________

iron(III)chloride_________________

sodiumcarbonate_________________

copper(II)sulfate_________________

magnesiumhydroxide_________________

bariumnitrate_________________

lithiumsulfate_________________

magnesiumchloride_________________

silvernitrate_________________

aluminumsulfate_________________

calciumhydroxide_________________

calciumsulfate_________________

mercury(II)nitrate_________________

lead(IV)nitrate_________________

magnesiumiodide_________________

sodiumnitride_________________

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PracticeProblemsKEY

sodiumbicarbonateNaHCO3

sodiumfluorideNaF

iron(III)chlorideFeCl3

sodiumcarbonateNa2CO3

copper(II)sulfateCuSO4

magnesiumhydroxideMg(OH)2

bariumnitrateBa(NO3)2

lithiumsulfateLi2SO4

magnesiumchlorideMgCl2

silvernitrateAgNO3

aluminumsulfateAl2(SO4)3

calciumhydroxideCa(OH)2

calciumsulfateCaSO4

mercury(II)nitrateHg(NO3)2

lead(IV)nitratePb(NO3)4

magnesiumiodideMgI2

sodiumnitrideNa3N

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WritingtheFormulasofCovalentCompounds

1) Writethesymbol/formulaofthefirstelementinthecompound’sname,thenthesymbol/formulaofthesecondelementinthecompound’sname.

2)Indicatehowmanyatomsofeachelementthemoleculecontainsusingsubscriptsaftertheatomicsymbol.

• Thenumbersofatomsaregiveninthemolecule’snameinGreekprefixes• NOTE:IfthereisnoGreekprefixinfrontofthefirstelementinthename,that

meansthenumberis1.Example:Writetheformulaofdinitrogentetrafluoride.1) Writethesymbol/formulaofthefirstelementinthecompound’sname,thenthe

symbol/formulaofthesecondelementinthecompound’sname.

NF2)Indicatehowmanyatomsofeachelementthemoleculecontainsusingsubscriptsaftertheatomicsymbol.

NF• Thenumbersofatomsaregiveninthemolecule’snameinGreekprefixes.

• dinitrogentetrafluoride• seeyourchapter3notesforalistoftheGreekprefixes

N2F4• NOTE:IfthereisnoGreekprefixinfrontofthefirstelementinthename,then

thenumberis1.• Examplecarbontetrachloride=CCl4

Example:Writetheformulaofcarbondisulfide.1) Writethesymbol/formulaofthefirstelementinthecompound’sname,thenthe

symbol/formulaofthesecondelementinthecompound’sname.

CS2)Indicatehowmanyatomsofeachelementthemoleculecontainsusingsubscriptsaftertheatomicsymbol.

CS• Thenumbersofatomsaregiveninthemolecule’snameinGreekprefixes.

• carbondisulfide• seeyourchapter3notesforalistoftheGreekprefixes

C1S2=CS2• NOTE:IfthereisnoGreekprefixinfrontofthefirstelementinthename,then

thenumberis1.

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Writetheformulasforthefollowingcovalentcompounds:

SeenextpageforKEY

a. disulfurtetrafluoride_________________________

b. carbontrioxide_________________________

c. nitrogenpentoxide_________________________

d. nitrogentribromide_________________________

e. dinitrogenheptachloride_________________________

f. carbontetrachloride_________________________

g. hydrogenmonochloride_________________________

h. trihydrogenmonophosphide_________________________

i. dihydrogenmonoxide_________________________

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KEY

a. disulfurtetrafluorideS2F4

b. carbontrioxideCO3

c. nitrogenpentoxideNO5

d. nitrogentribromideNBr3

e. dinitrogenheptachlorideN2Cl7

f. carbontetrachlorideCCl4

g. hydrogenmonochlorideHCl

h. trihydrogenmonophosphideH3P

i. dihydrogenmonoxideH2O

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GiventheFormulasforCompounds,WritetheName

DetermineiftheCompoundisBinaryCovalent(Molecular)orIonic:

Doesthecompoundcontainonlytwotypesofnonmetalelements?

Yes No

BinaryCovalent(Molecular)Compound:

1)Listthenameofthefirstelementintheformula.

2)Listthesecondelementandaddthe"ide"suffix.

3)UseGreekprefixestoindicatethenumberofeachatomintheformula.• Exception:Donotusemono-forthe

firstelementinthename.• TheooraattheendoftheGreek

prefixisdroppedwhentheelementnamebeginswithavowel.

IonicCompound:1)Writethecationnamefirst,thennametheanion.

• Monoatomicanionsusethe“ide”suffix

2)Ifthecationisoneofthemetalswithvariouscharges,writethechargeusingparenthesisandRomannumeralsafterthemetalname.

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WritingtheNamesofIonicCompoundsExample:WritethenameforCaBr21) Writethecationnamefirst,thennametheanion.

• monoatomicanionsusethe“ide”suffixcalciumbromide

2)Ifthecationisoneofthetransitionmetalswithvariouscharges,writethechargeusingparenthesisandRomannumeralsafterthemetalname.

• Notnecessaryhere,thereisnotatransitionmetalpresentExample:WritethenameforMg(NO3)21) Writethecationnamefirst,thennametheanion.

• monoatomicanionsusethe“ide”suffix• Herewenoticethattheanionisapolyatomicion.Getthenamefromthe

polyatomiciontable(inyournotesortextbook).Youwillbegivenacopyofthepolyatomiciontableonyourexams.

• Donotchangethesuffixto“ide”withpolyatomicions:magnesiumnitrate

2)Ifthecationisoneofthetransitionmetalswithvariouscharges,writethechargeusingparenthesisandRomannumeralsafterthemetalname.

• Notnecessaryhere,thereisnotatransitionmetalpresent

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WritingtheNamesofIonicCompounds

Example:WritethenameforCuF21) Writethecationnamefirst,thennametheanion.

• monoatomicanionsusethe“ide”suffixcopperfluoride

2)Ifthecationisoneofthetransitionmetalswithvariouscharges,writethechargeusingparenthesisandRomannumeralsafterthemetalname. copper(?)fluoride

• Wemustfigureoutwhatthechargeisonthecopper,wecandeducethechargeonthetransitionmetalcationsfromthechargeontheanions• Recallthatthetotalchargeforanycompoundmustequalzero.• Sincetherearetwofluorides,eachwithachargeof(1-)andthereisonly

onecopper,wecanconcludethatthechargeonthecoppermustbe(2+).• Youcanthinkofthisasthereversecriss-cross!Seechapter3

notesformoredetails.copper(II)fluoride

writethechargeinparenthesisinRomannumeralsafterthecationname

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Writethenamesofthefollowingcompounds:

Seenextpageforkey

NaCl__________________________________________

Fe2(CO3)3__________________________________________

Cu(OH)2__________________________________________

(NH4)2SO4__________________________________________

LiNO3__________________________________________

BaSO4__________________________________________

Mg(NO3)2__________________________________________

AgCl__________________________________________

Al(OH)3__________________________________________

CaSO4__________________________________________

FeS__________________________________________

FeCl3__________________________________________

NaI__________________________________________

MgCO3__________________________________________

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KEY

NaClsodiumchloride

Fe2(CO3)3iron(III)carbonate

Cu(OH)2copper(II)hydroxide

(NH4)2SO4ammoniumsulfate

LiNO3lithiumnitrate

BaSO4bariumsulfate

Mg(NO3)2magnesiumnitrate

AgClsilverchloride

• (note:silverisoneofthetransitionmetalsthatonlyoccursasa(1+)ion)Al(OH)3aluminumhydroxide

CaSO4calciumsulfate

FeSIron(II)sulfide

FeCl3iron(III)chloride

NaIsodiumiodide

MgCO3magnesiumcarbonate

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WritingtheNamesofCovalentCompounds1)Listthenameofthefirstelementintheformula.2)Listthesecondelementandaddthe–idesuffix. 3)UseGreekprefixestoindicatethenumberofeachatomintheformula.

• Exception:donotusemono-forthefirstelementinthename.• TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelement

namebeginswithavowelExample:WritethenameforN2S41)Listthenameofthefirstelementintheformula. nitrogen2)Listthesecondelementandaddthe–idesuffix. nitrogensulfide3)UseGreekprefixestoindicatethenumberofeachatomintheformula.

• SeeyourtextbookorlecturenotesforatableoftheGreekprefixes. ____nitrogen_____sulfide dinitrogentetrasulfide

• Exception:donotusemono-forthefirstelementinthename.• Notapplicableinthisexample

• TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelementnamebeginswithavowel• Notapplicableinthisexample

Example:WritethenameforSO31)Listthenameofthefirstelementintheformula. sulfur2)Listthesecondelementandaddthe–idesuffix. sulfuroxide3)UseGreekprefixestoindicatethenumberofeachatomintheformula. ____sulfur_____oxide sulfurtrioxide

• Exception:donotusemono-forthefirstelementinthename.• NOTE,wedidnotwritemonosulfurbecauseofthisrule!

• TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelementnamebeginswithavowel• Notapplicableinthisexample

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Example:WritethenameforSO21)Listthenameofthefirstelementintheformula. sulfur2)Listthesecondelementandaddthe–idesuffix. sulfuroxide3)UseGreekprefixestoindicatethenumberofeachatomintheformula. ____sulfur_____oxide sulfurdioxide

• Exception:donotusemono-forthefirstelementinthename.• NOTE,wedidnotwritemonosulfurbecauseofthisrule!

• TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelementnamebeginswithavowel• Notapplicableinthisexample

Example:WritethenameforCO1)Listthenameofthefirstelementintheformula. carbon2)Listthesecondelementandaddthe–idesuffix. carbonoxide3)UseGreekprefixestoindicatethenumberofeachatomintheformula. ____carbon_____oxide carbonmonoxide

• Exception:donotusemono-forthefirstelementinthename.• NOTE,wedidnotwritemonocarbonbecauseofthisrule!

• TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelementnamebeginswithavowel• NOTE,wedidnotwritemonooxidebecauseofthisrule!

Writethenamesofthefollowingcompounds:Seenextpageforkey

a. Br2I4________________________________________

b. P5F8________________________________________

c. NO5________________________________________• Remember:TheooraattheendoftheGreekpre-fixisusuallydroppedwhen

theelementnamebeginswithavoweld. NBr3________________________________________

e. N2O5________________________________________

f. BrCl3________________________________________

g. H2S________________________________________

h. N2O________________________________________

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KEYa. Br2I4dibrominetetriodide

b. P5F8pentaphosphorusoctafluoride

c. NO5nitrogenpentoxideo TheooraattheendoftheGreekpre-fixisusuallydroppedwhentheelement

namebeginswithavowel§ NOTE,wedidnotwritepentaoxygenbecauseofthisrule!

d. NBr3nitrogentribromide

e. N2O5dinitrogenpentoxide

f. BrCl3brominetrichloride

g. H2Sdihydrogenmonosulfide

h. N2Odinitrogenmonoxide

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