Chemical Formulas IONIC COMPOUNDS

Chemical Formulas Chemical formula - a symbolic representation of chemical compounds; contains: elements in compound (symbols) # of atoms in each element NaCl – sodium-one atom & chlorine-one atom H 2 O – Hydrogen-2 atoms & oxygen-one atom

Types of Chemical Formula Ionic Giving and Taking of Electrons Covalent Share of electrons

Types of Chemical Formulas Ionic – metal and non-metal → transfer of electrons (e-) Cation – lose e-, + charge (metals) Anion – gain e-, - charge (non-metals) H+ is the exception to this rule! H – acts like a metal – has + charge 11 e — 11 p + 10 e _ 11 p +

Types of Ionic Compounds There are 2 types of Ionic compounds: Binary Ionic Compounds Ternary Ionic Compounds

Naming Binary Ionic Compounds monoatomic + monoatomic (one atom + one atom) 1 cation (+) + anion (-) Examples zinc oxide Zn + O= ZnO magnesium chloride Mg + Cl= MgCl 2 aluminum oxide Al + O= Al 2 O 3 Naming Binary Ionic Compounds Begin with name of Cation Normally elements name End with name of Anion Normally has –ide or –ate ending If cation has multiple charges, you must indicate using roman numerals (Stock Naming System)

Transition Metals (Valley Elements– elements with multiple charges Ions that are formed from transition metals may have multiple or more than 1 charge Examples Fe +2 Iron (II) Ion Fe +3 Iron (III) Ion Cu + Copper(I) or Cuprous Ion Cu 2+ Copper(II) or Cupric Ion All Transition metals must be followed by a roman numeral when naming

Transition Metals (Valley Elements)– elements with multiple charges Exceptions: Zinc Cadmium Silver Additions: Tin Bismuth Lead Antimony

Ternary Ionic Compounds Compounds that contain 3 or more ions One must be a polyatomic ion Cation + Polyatomic Anion = Ternary Ion Examples Potassium Nitrate K + NO 3 = KNO 3 Naming Ternary Ionic Compounds Begin with name of Cation Normally elements name End with name of Anion Normally has –ide (hydroxide and cyanide) or –ate ending

Polyatomic Ions – pg. 221 Polyatomic Ions are ions that are composed of two or more different elements Again you have Positive Polyatomic Ions= Negative Polyatomic Ions= We will only talk about one positive polyatomic ion which is ammonium ion (NH 4 +1 )

Writing Binary and Ternary Formulas NameCationAnionEquation Sodium Chloride Iron(III) Oxide Iron(II) Nitrate Copper(II) Sulfate