Ionic Compounds Naming Naming Binary Ionic Compounds 1

Ionic Compounds: Naming

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

Stems of nonmetals Nitr Ox Fluor Phosph Sulf Chlor Arsen Selen Brom Tellur Iod Hydr is the stem for H

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 • • 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 • Use formula to figure out which oxidation # for the metal ion – Ex: Fe can be Fe+2 or Fe+3 • Name 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 = 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 There are 3 O’s 3 X (-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 • group of covalently bonded atoms that have a charge • Table E: (+)’ve or (–)’ve • polyatomic ions have “names” • (-) polyatomic ions can form ionic bonds with (+) metal ions SO 42 - CO 32 - PO 43 - OH-

Ternary Compounds • contain 3 or more elements • usually contain a polyatomic ion – if polyatomic is (+) it’s bonded to a nonmetal – 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

Some of the most challenging are • • • 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 is parallel to binary naming positive always written first if (+)’ve ion is a metal, check to see how many oxidation states it has – if more than 1, name must have 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 first • If metal has more than 1 oxidation state, name has roman numeral • Name = metal + stem of nonmetal + ide