Names and Formulas of Ionic Compounds 5.3

Naming Binary Ionic Compounds Binary Ionic Compound (BIC) -ionic compound made up of two ions To name cation – use name of atom Na+ = sodium K+ = potassium Ca2+ = calcium Ba2+ = barium

Naming Anions To name anions, use the atom’s base name and –ide at the end Cl- = Chloride S2- = Sulfide P3- = Phosphide O2- = Oxide KBr = Potassium bromide Mg3N2 = Magnesium nitride

Writing Ionic Formulas Write the symbol and charge of each ion side by side (cation first) If total = 0, just write symbols & you are done! If total does not = 0, criss cross charges to have overall 0 charge

Examples CaS CsF K3P Rubidium Chloride Barium Sulfide Beryllium Iodide

Multiple Charge Cations/Transition Metals If cation has multiple charges, use a roman numeral to indicate charge Cu+ =Copper (I) Cu+2 =Copper (II) I = 1 II = 2 III = 3 IV = 4 V = 5 VI= 6 VII = 7 VIII = 8 IX = 9 X = 10

Determining Charge on Transition Metals The charge on ionic compounds has to be electrically neutral Figure out overall charge on anion and then determine what charge cation has to be CuCl2 ~Each Cl has a charge of -1 (needs 1 e-) and since there are 2 of them, the overall charge of Cl is -2. Cu must be +2 = Copper (II) chloride

Determining Charge on Transition Metals PbO2 Charge on O is -2 and there are 2 of them so overall on O is -4. Pb has to be +4 Lead (IV) oxide

Examples Magnesium sulfide Rubidium Oxide Strontium Bromide Aluminum Oxide Vanadium (III) Iodide Platinum (IV) oxide

Naming FrF SrBr2 CuO Hg2O Cu2O Li2Se

Polyatomic Ions Polyatomic Ion – an ion made of 2 or more atoms that behave like a single ion Bonded covalently Bond ionically with other simple ions as salts

Name changes as number of O changes Oxyanions Name changes as number of O changes Gain 1 O = perchlorate ClO4- Base Name = chlorate ClO3- Lose 1 O = chlorite ClO2- Lose 2 O = hypochlorite ClO-

Hydrogen and Sulfur The name usually starts with the word hydrogen, but use mono- and di- HPO4 –monohydrogen phosphate H2PO4 – dihydrogen phosphate Thio – replace O with S K2S2O3 – Potassium thiosulfate

Naming Compounds w/polyatomics Name the ion that is not a polyatomic like simple cations or anions and then name the polyatomic as the chart says NaOH = Sodium hydroxide CaCO3 = Calcium carbonate

Polyatomic Ions AlPO3 LiSCN FeSO4 Mn(Cr2O7)2

Formula Writing w/polyatomics Determine charge of overall polyatomic and then the other ion. Follow same rules as before. Beryllium cyanide Copper (II) nitrate

Polyatomic Ions Barium sulfide Potassium oxalate Chromium (III) cyanide Vanadium (V)silicate