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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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