Ionic Compounds: Naming

Naming Binary Ionic Compounds

1. Always name metal [(+) cation] first

2. Write stemstem of non-metal [(-) anion]

3. Add ending “ide” to non-metal

Stems of nonmetalselement stemnitrogen nitr

phosphorus phosph

arsenic arsen

selenium selen

oxygen ox

bromine brom

iodine iod

flourine fluor

chlorine chlor

The First Step in NamingThe First Step in Naming

• Find metal on PT• If metal has only one oxidation state i

t’s easy• If metal has more than one oxidation

state, there’s an extra step

Metals with one oxidation state(name metal, stem non-metal, add “ide”)

• CaO• BaS• AlN• LiCl• Al2Se3

• Na2O• K3N• MgF2

calcium oxcalcium oxideidebarium sulfbarium sulfideidealuminum nitraluminum nitrideidelithium chlorlithium chlorideide

aluminum selenaluminum selenideidesodium qxsodium qxideide

potassium nitrpotassium nitrideide

magnesium fluormagnesium fluorideide

Metals with more than 1 oxidation state

• figure out which oxidation # for metal ionfigure out which oxidation # for metal ion– Ex: Fe can be Fe+2 oror Fe+3

• FeO and Fe2O3 – two differenttwo different compounds – cannot name both iron oxide – every formula has 1 name only

FeO and Fe2O3

• Compounds are electrically neutral• Oxygen is -2

FeOFeO

Name: Name: iron (II) oxideiron (II) oxide(roman numeral II represents +2 charge on Fe)(roman numeral II represents +2 charge on Fe)

1 O which is -21 O which is -2 so Fe must be +2so Fe must be +2

FeO and Fe2O3

• Compounds are electrically neutral• Oxygen is -2

FeFe22OO33

each O is -2each O is -2

3 O3 O’’s 3(-2) = -6s 3(-2) = -6total negative chargetotal negative charge

total positive charge total positive charge must be +6must be +6

each Fe is +3each Fe is +3iron (III) oxideiron (III) oxide

Name the following

• TiCl3• Mn2O4

• Co2O3

• PdBr2

• AuCl3• MoN• MnO• TiO

titanium (III) chloridetitanium (III) chloride

manganese (IV) oxidemanganese (IV) oxide

cobalt (III) oxidecobalt (III) oxidepalladium (II) bromidepalladium (II) bromidegold (III) chloridegold (III) chloride

molybdenum (III) nitridemolybdenum (III) nitridemanganese (II) oxidemanganese (II) oxidetitanium (II) oxidetitanium (II) oxide

POLYATOMIC IONSPOLYATOMIC IONS

• Table E: groups of covalently bonded atoms that have a charge (+) or (–)

• polyatomic ions have “names”• (-) polyatomic ions can form ionic bonds

with (+) metal ions

SOSO442-2- CO CO33

2-2- PO PO443-3- OH OH1-1-

Ternary Compounds

• contain 3 or more elements • usually contain a polyatomic ion

– if polyatomic is (+) it’s bonded to a non-metal– if polyatomic is (–) it’s bonded to a metal–sometimes 2 polyatomics are bonded

together

Formulas with polyatomicsFormulas with polyatomics

• What’s the formula for the compound formed from Al+3 and SCN-1?

• The charges must add up to zero, so write the symbols, positive first!

Al(SCN)Al(SCN)33

Try a few more:

• Na+1 and OH-1

• K +1 and HCO3-1

• Mg+2 and CO3-2

• Li +1 and NO3-1

• Ca+2 and SO4-2

NaOHNaOH

KHCOKHCO33

MgCOMgCO33

LiNOLiNO33

CaSOCaSO44

These are more challenging:

• Mg+2 and (PO4)-3

• Al+3 and (NO3)-1

• Fe+2 and OH-1

• Hg2+2 and SCN-1

• Mg+2 and HCO3-

• Al+3 and C2O42-

MgMg33(PO(PO44))22

Al(NOAl(NO33))33

Fe(OH)Fe(OH)22

HgHg22(SCN)(SCN)22

Mg(HCOMg(HCO33))22

AlAl22(C(C22OO44))33

More challenging

• zinc + nitrate ion• magnesium + hydroxide ion• lithium + carbonate ion• potassium + sulfate ion• calcium + phosphate ion• beryllium + chlorate ion

Zn(NOZn(NO33))22

Mg(OH)Mg(OH)22

LiLi22COCO33

KK22SOSO44

CaCa33(PO(PO44))22

Be (ClOBe (ClO33))22

Naming compounds with polyatomics

• polyatomic ions have names (Table E)• Naming similar to binary naming• Rules:

– positive always written first– if (+)’ve ion is a metal, check to see how many

oxidation states it has • if more than 1, need roman numeral

– if (–)’ve ion is polyatomic - 2nd part of name is name of polyatomic (don’t modify ending)

Name the following

• NaOHNaOH• KHCOKHCO33

• LiNOLiNO33

• CaSOCaSO44

• Al(NOAl(NO33))33

• Fe(OH)Fe(OH)22

• CuSOCuSO44

• CuSCNCuSCN

sodium hydroxidesodium hydroxide

potassium hydrogen carbonatepotassium hydrogen carbonatelithium nitratelithium nitrate

calcium sulfatecalcium sulfatealuminum nitratealuminum nitrateiron (II) hydroxideiron (II) hydroxide

copper (II) sulfatecopper (II) sulfatecopper (I) thiocyanatecopper (I) thiocyanate

Summary for Binary Ionic Summary for Binary Ionic CompoundsCompounds

• Compounds are electrically neutral

• Formula: positive ion goes first

• If metal has more than 1 oxidation state, name has roman numeral

• Name = metal + stem of nonmetal + ide