Notes

Outline

Atoms, Molecules and Ions Part II- Formulas, Nomenclature, and Equation Balancing

Types of Compounds Ionic - Compounds composed of Ions Cations- Positively charged atoms as a result of losing one or more electrons Anions- Negatively charged atoms as a result of gaining one or more electrons Molecular- Compounds composed of neutral molecules

Types of Formulas Simple (Empirical) Formulas Molecular Formula Structural Formula

Simpliest (Empirical)Formulas Formula whose subscripts represent simpliest whole number ratio of atoms per molecule or mols of elements per mol of compound Example: CH2O means that there are twice as many Hydrogen atoms as there are Carbon or Oxygen atoms Ionic compounds have only simpliest formulas

Molecular Formulas Formula whose subscripts represent absolute numbers of atoms per molecule of compound or absolute numbers of mols of each element per mol of compound Examples C6H12O6 means that a single molecule has 6 atoms of Carbon, 12 atoms of Hydrogen, and 6 atoms of Oxygen Molecular compounds have molecular and empirical formulas

Structural Formulas Formula that identifies the way the atoms are connected Different Methods To Picture Molecules Examples

T-2.15 Molecular and Structural Formulas

T-2.16 Molecular Models of Molecular Elements

Ions and Ionic Compounds Metals+Non-metals -àIonic Compounds Cations + Anions à Ionic Compounds Total Charge must be zero (total positive and total negative must add up to zero)

T-61  Charges of Some Common Ions Found In Ionic Compounds

Binary And Ternary Compounds Binary Compound-Compound composed of two elements Examples- HCl, H2O, NaCl, AlCl3 Ternary Compound- Compound composed of three or more elements Examples- H2SO4, K2CO3, HClO4

Naming Binary Ionic Compounds From Formula Name the metal cation using element name Name the non-metalic anion ending in “ide” If multi-valent metallic cation involved identify the valence in parenthesis Examples

Determining The Formula Of A Binary Ionic From the Name Identify the symbol for metal and non-metal Identify the oxidation state in parenthesis for each Determine what multiple of each to get a balance between positive and negative Multiple will be the subscript Place the metallic cation element first Examples

T-2.6 Polyatomic Ions

Naming Ternary Ionic Compounds Using The Formula Name the metal cation using element name Name the non-metallic anion If multi-valent metallic cation involved identify the valence in parenthesis Examples

Writing the Formula of Ternary Compound Using The Name Identify the symbol for metal and non-metal Identify the oxidation state in parenthesis for each Determine what multiple of each to get a balance between positive and negative Multiple will be the subscript Place the metallic cation element first If more than one polyatomic ion involved enclose the polyatomic ion in parenthesis and place the subscript on the outside. Examples

T-2.8 Oxoanions and Oxoacids

Naming Molecular Compounds From The Formula If more than one atom involved in the formula use greek prefixes Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Examples

Determining Formulas of Molecular Compounds Using The Name If no prefix or if prefix is “mono” the subscript will be one understood If di subscript will be 2 If tri subscript will be 3 If tetra subscript will be 4 Examples

Hydrate Compounds Hydrates-ionic salts that have water molecules physically locked into the crystal structure Water called “water of hydration” and is part of composition

Determining the Formula Of A Hydrate From The Name Write the formula of the anhydrous portion as before Attach the number of water molecules in the Hydrate to the formula of the anhydrous portion according to the greek prefix used in the name given Examples

Determining the Name of A Hydrate From The Formula Name the anhydrous portion as before Identify the number of waters from the Formula given Attach the proper prefix to the word Hydrate right after the anhydrous name Examples