The Name Game: Ionic Compounds 1.The cation comes first in the name (and in the formula) and it retains the name of the element. 2.If the compound contains a transition metal cation, the oxidation number of the cation is indicated in parentheses in roman numerals. Ex: Au 3+  gold( III ) 3. The name of the anion is changed so that it ends in -ide Ex: chlorine  chloride, oxygen  oxide AuCl 3 Gold( III ) chloride PbO 2 Lead(IV) oxide Metals in Group 14 can often have more than one oxidation number Na 3 NSodium nitride PbBr 2 Lead( II ) bromide

Now, you try some... AgF Silver( I ) fluoride Al 2 S 3 Aluminum sulfide MgCl 2 Magnesium chloride FeCl 3 Iron( III ) chloride TiO 2 Titanium( IV ) oxide

Polyatomic ions are made of more than one atom AND carry a charge. 1 P + 4 O + 3 e-PO 4 -3 Whenever you are writing a formula with a polyatomic ion, imagine that it is surrounded by a force field that prevents the atoms in the ion from separating. Phosphate ion

Polyatomic ions that you need to know are: PO 4 -3 SO 4 -2 CO 3 -2 NO 3 -1 ClO 3 -1 OH -1 C 2 H 3 O 2 -1 NH 4 +1 Phosphate Sulfate Carbonate Nitrate Chlorate Hydroxide Acetate Ammonium Pg 619

The key to success is recognizing the polyatomic ions. NH 4 Cl NH 3 Na 4 C Na 2 SO 4 Na 2 S NaNO 3 SO 2 CO 2 MgCO 3 NaCl NaClO 3 NaOH NH 4 OH H 3 PO 4 PCl 3 AuPO 4 AuP Au 2 O

Some ionic compounds with polyatomics… Aluminum and nitrate Al +3 NO 3 -1 Ammonium and carbonate Al(NO 3 ) 3 NH 4 + CO 3 -2 NO 3 - Al +3 Aluminum and phosphate Al +3 PO 4 -3 Al +3 PO 4 -3 AlPO 4 Ionic compounds are called formula units, NOT molecules. CO 3 -2 NH 4 + (NH 4 ) 2 CO 3

Now you try some… Write the formulas for the following combinations 1.Sodium and phosphate 2.Ammonium and sulfur 3.Carbonate and silver( I ) 4.Hydroxide and zinc( II ) 5.Phosphate and iron( II ) 6.Ammonium and carbonate 7.Gold( III ) and acetate Na 3 PO 4 (NH 4 ) 2 S Ag 2 CO 3 Zn(OH) 2 Fe 3 (PO 4 ) 2 (NH 4 ) 2 CO 3 Au(C 2 H 3 O 2 ) 3

Naming ionic compounds containing polyatomic ions 1.The cation comes first in the name (and in the formula) and it retains the name of the element or the ion if ammonium. 2.The polyatomic anion retains its name. Ex: CaSO 4 would be calcium sulfate NH 4 Cl NH 4 ClO 4 would be ammonium chloride would be ammonium perchlorate