Ionic Compounds: Naming

Naming Binary Ionic Compounds 1.Always name metal [(+) cation] first stem 2. Write stem of non-metal [(-) anion] 3. Add ending “ide” to non-metal

Stems of nonmetals elementstem nitrogennitr phosphorusphosph arsenicarsen seleniumselen oxygenox brominebrom iodineiod flourinefluor chlorinechlor

The First Step in Naming Find metal on PT If metal has only one oxidation state it’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 Al 2 Se 3 Na 2 O K 3 N MgF 2 calcium oxide barium sulfide aluminum nitride lithium chloride aluminum selenide sodium qxide potassium nitride magnesium fluoride

Metals with more than 1 oxidation state figure out which oxidation # for metal ionfigure out which oxidation # for metal ion or –Ex: Fe can be Fe +2 or Fe +3 FeO and Fe 2 O 3 – two different – two different compounds – cannot name both iron oxide – every formula has 1 name only

FeO and Fe 2 O 3 Compounds are electrically neutral Oxygen is -2 FeO Name: iron (II) oxide (roman numeral II represents +2 charge on Fe) 1 O which is -2 so Fe must be +2 so Fe must be +2

FeO and Fe 2 O 3 Compounds are electrically neutral Oxygen is -2 Fe 2 O 3 each O is -2 3 O’s 3(-2) = -6 total negative charge total positive charge must be +6 each Fe is +3 iron (III) oxide

Name the following TiCl 3 Mn 2 O 4 Co 2 O 3 PdBr 2 AuCl 3 MoN MnO TiO titanium (III) chloride manganese (IV) oxide cobalt (III) oxide palladium (II) bromide gold (III) chloride molybdenum (III) nitride manganese (II) oxide titanium (II) oxide

POLYATOMIC 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 SO 4 2- CO 3 2- PO 4 3- OH 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 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) 3

Try a few more: Na +1 and OH -1 K +1 and HCO 3 -1 Mg +2 and CO 3 -2 Li +1 and NO 3 -1 Ca +2 and SO 4 -2 NaOH KHCO 3 MgCO 3 LiNO 3 CaSO 4

These are more challenging: Mg +2 and (PO 4 ) -3 Al +3 and (NO 3 ) -1 Fe +2 and OH -1 Hg 2 +2 and SCN -1 Mg +2 and HCO 3 - Al +3 and C 2 O 4 2- Mg 3 (PO 4 ) 2 Al(NO 3 ) 3 Fe(OH) 2 Hg 2 (SCN) 2 Mg(HCO 3 ) 2 Al 2 (C 2 O 4 ) 3

More challenging zinc + nitrate ion magnesium + hydroxide ion lithium + carbonate ion potassium + sulfate ion calcium + phosphate ion beryllium + chlorate ion Zn(NO 3 ) 2 Mg(OH) 2 Li 2 CO 3 K 2 SO 4 Ca 3 (PO 4 ) 2 Be (ClO 3 ) 2

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 - 2 nd part of name is name of polyatomic (don’t modify ending)

Name the following NaOHNaOH KHCO 3KHCO 3 LiNO 3LiNO 3 CaSO 4CaSO 4 Al(NO 3 ) 3Al(NO 3 ) 3 Fe(OH) 2Fe(OH) 2 CuSO 4CuSO 4 CuSCNCuSCN sodium hydroxide potassium hydrogen carbonate lithium nitrate calcium sulfate aluminum nitrate iron (II) hydroxide copper (II) sulfate copper (I) thiocyanate

Summary for Binary Ionic Compounds 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