3.2 Names and Formulas of Ionic Compounds INCREASING REACTIVITY (c) McGraw Hill Ryerson 2007 See page 85

Naming Simple Ionic Compounds Rules for naming simple ionic compounds: Write the name of the metal (positive ion) first. Write the name of the non-metal (negative ion) second. Change the ending of the non-metal ion to “ide.” (c) McGraw Hill Ryerson 2007

Naming Simple Ionic Compounds Examples: Li3N __________________________ MgBr2 __________________________ Ag2O __________________________ CdS __________________________ (c) McGraw Hill Ryerson 2007

Naming Simple Ionic Compounds (c) McGraw Hill Ryerson 2007

Writing Formulas for Simple Ionic Compounds Rules for writing formulas for ionic compounds: STEP ONE: Write the symbol for the more metallic element first. Then, write the symbol for the non-metallic element. STEP TWO: Write the combining capacities for the elements. Ignore the + and – charges. *If there is no #, the combining capacity is 1. STEP THREE: Swap and drop the combining capacities to get the subscripts. (c) McGraw Hill Ryerson 2007

Writing Formulas for Simple Ionic Compounds Examples: Barium phosphide ______________ Aluminum nitride ______________ Zinc oxide ______________ Rubidium bromide ______________ (c) McGraw Hill Ryerson 2007

Multivalent Metal Compounds Many metals are multivalent, meaning the metals form two or more different positive ions with different charges. For example, the atom iron forms two ions Fe2+ and Fe3+. (c) McGraw Hill Ryerson 2007 See page 88

Multivalent Metal Compounds To distinguish different ions for the same metal, roman numerals are added to their name. For example, Fe3+ would be named “iron(III)” (c) McGraw Hill Ryerson 2007

Writing Formulas for Ionic Compounds Containing Multivalent Metals It is easy to write the formulas for multivalent ionic compounds, because they tell you their combining capacities so you don’t need to look on the periodic table. (c) McGraw Hill Ryerson 2007 See page 89

Writing Formulas for Ionic Compounds Containing Multivalent Metals Examples: Iron (II) phosphide ______________ Manganese (II) oxide ______________ Tin (II) sulfide ______________ Lead (IV) chloride ______________ (c) McGraw Hill Ryerson 2007

Naming Ionic Compounds Containing Multivalent Metals It is a little more difficult to name a multivalent ionic compound, because you have to work backwards to figure out which combining capacity was used. Remember to use a ROMAN NUMERAL!!! (c) McGraw Hill Ryerson 2007 See page 90

Naming Ionic Compounds Containing Multivalent Metals Examples: Fe2O3 __________________________ PbF4 __________________________ MnS __________________________ TiS2 __________________________ (c) McGraw Hill Ryerson 2007

Naming Ionic Compounds Containing Polyatomic Ions When you are naming compounds with more than two elements, you are dealing with a polyatomic ion. All you need to do, is find it in the chart so you can name your compound. If the polyatomic ion group has a positive charge (+) it acts like a metal and comes first in the name. If the polyatomic ion group has a negative charge (-) it acts like a non-metal and comes second in the name. (c) McGraw Hill Ryerson 2007

Naming Ionic Compounds Containing Polyatomic Ions Examples: Fe(OH)3 ________________________ Mg3(PO4)2 ________________________ (NH4)3P ________________________ Ca(CH3COO)2 ________________________ (c) McGraw Hill Ryerson 2007 See page 91

Writing Formulas for Ionic Compounds Containing Polyatomic Ions Each polyatomic ion has its own combining capacity that should be used when writing a chemical formula. USE BRACKETS AROUND THE POLYATOMIC IONS!! (c) McGraw Hill Ryerson 2007 See page 91

Writing Formulas for Ionic Compounds Containing Polyatomic Ions Examples: Sodium chromate ________________ Ammonium nitrate ________________ Lead (II) perchlorate ________________ Tin (II) cyanide ________________ (c) McGraw Hill Ryerson 2007 Section 3.2 Quiz See page 91