Ionic Compounds Think SALT

Definitions Formed by transfer of electrons Ions (charged particles) are formed Attraction between + and – ions holds the ions together Very strong bond

RULES for NAMES & FORMULAS For ALL IONIC Compounds Name the Metal 1 st /Non-metal 2 nd or + then -- ion 2 elements use IDE ending for non-metal. It is a Binary compound (2 elements). 3 or more elements means the compound is not Binary. LOOK at Table E, then write the metal name then the name of the polyatomic ion. The name will end ATE or ITE.

Let’s try to name some ionic compounds…. Formula NaCl MgCl 2 Li 2 O LiOH Sr 3 P 2 AlPO 4 Mg 3 (PO 4 ) 2 Name Sodium chloride Magnesium chloride Lithium oxide Lithium hydroxide Strontium phosphide Aluminum phosphate Magnesium phosphate

Rules for formula writing 1. Write the symbols of all elements 2. If ATE or ITE ending… use table E 3. Find the oxidation states (charges) 4. Write the charge to the top right of each element 5. Cross over and down 6. Don’t show charges 7. All charges must add up to ZERO!!! 8. Don’t show ones 9. Reduce 10. A Roman numeral gives the charge of the metal in the compound 11. Put parenthesis around polyatomic ions

Here is an example

Let’s try to write a formula….. Calcium nitride Radium bromide Lithium bromide Calcium sulfide Calcium phosphate Potassium sulfate Ca 3 N 2 RaBr 2 LiBr CaS Ca 3 (PO 4 ) 2 K 2 SO 4

Elements Rules for names of Ionic Compounds with Polyvalent Elements If the metal has more than one oxidation state the name for its compound needs a ROMAN NUMERAL IN THE MIDDLE EX…. iron III oxide….. Fe 2 O 3 The Roman # is the + charge of the metal ion EX…. Iron III = Fe +3 Copper II = Cu +2 manganese VII = Mn +7 All other Rules Apply

Let’s name some compound with polyvalent metals( they have many + charges)….. Formula FeO CuCl AuCN Ni(OH) 2 Name Iron II oxide Copper I chloride Gold I cyanide Nickel II hydroxide

Properties of Ionic and Covalent Compounds IONIC Loss or gain of electrons Metal bonded to nonmetal Very high M.P./B.P. Dissolve in water Or water soluble Crystalline solids (ions arranged in a geometric pattern Electrolytes :conduct electricity when dissolved in water or molten (liquids) Strong bonds: attraction between + and - ELECTRONEGATIVITY difference (END) 1.7 or higher Ionize or dissociate in water (break apart into ions) COVALENT Sharing of electrons All nonmetals bonded Low M.P./B.P. Solubility depends on polarity Molecular solids which are soft and amorphous (no shape, like butter) Non-electrolytes Weaker bonds due to overlapping valence levels Polar (unequal sharing) END NON-Polar (equal sharing) END = 0 Do not IONIZE or Break apart in water