Ionic Compounds Naming Naming Binary Ionic Compounds 1
Ionic Compounds: Naming
Naming Binary Ionic Compounds 1. Always name metal [(+) cation] first 2. Write stem of non-metal [(-) anion] 3. Add ending “ide” to non-metal
Stems of nonmetals element stem nitrogen nitr phosphorus phosph arsenic arsen selenium selen oxygen ox bromine brom iodine iod flourine fluor chlorine chlor
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”) • • Ca. O calcium oxide Ba. S barium sulfide Al. N aluminum nitride Li. Cl lithium chloride Al 2 Se 3 aluminum selenide Na 2 O sodium qxide K 3 N potassium nitride Mg. F 2 magnesium fluoride
Metals with more than 1 oxidation state • figure out which oxidation # for metal ion – Ex: Fe can be Fe+2 or Fe+3 • Fe. O and Fe 2 O 3 – two different compounds – cannot name both iron oxide – every formula has 1 name only
Fe. O and Fe 2 O 3 • Compounds are electrically neutral • Oxygen is -2 Fe. O 1 O which is -2 so Fe must be +2 Name: iron (II) oxide (roman numeral II represents +2 charge on Fe)
Fe. O and Fe 2 O 3 • Compounds are electrically neutral • Oxygen is -2 each Fe is +3 iron (III) oxide each O is -2 Fe 2 O 3 total positive charge must be +6 3 O ’s 3(-2) = -6 total negative charge
Name the following • • Ti. Cl 3 titanium (III) chloride Mn 2 O 4 manganese (IV) oxide Co 2 O 3 cobalt (III) oxide Pd. Br 2 palladium (II) bromide Au. Cl 3 gold (III) chloride Mo. N molybdenum (III) nitride Mn. O manganese (II) oxide Ti. O 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 42 - CO 32 - PO 43 - 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 Na. OH K +1 and HCO 3 -1 KHCO 3 Mg+2 and CO 3 -2 Mg. CO 3 Li +1 and NO 3 -1 Li. NO 3 Ca+2 and SO 4 -2 Ca. SO 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 42 - 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 • • • Zn(NO 3)2 zinc + nitrate ion magnesium + hydroxide ion Mg(OH)2 lithium + carbonate ion Li 2 CO 3 K 2 SO 4 potassium + sulfate ion calcium + phosphate ion Ca 3(PO 4)2 beryllium + chlorate ion Be (Cl. O 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 • • Na. OH sodium hydroxide KHCO 3 potassium hydrogen carbonate Li. NO 3 lithium nitrate Ca. SO 4 calcium sulfate Al(NO 3)3 aluminum nitrate Fe(OH)2 iron (II) hydroxide Cu. SO 4 copper (II) sulfate Cu. SCN 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
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