Ionic Bonds and Nomenclature Unit 2 Notes

IONIC BONDING Ionic Bond - strong attraction (electrostatic attraction) formed between a cation (+) and anion (-) The cation and anion are formed when a metal donates electrons to a nonmetal in order to fulfill the octet rule (8 valence electrons)

IONIC BONDING The cation and anion are formed when a metal donates electrons to a nonmetal in order to fulfill the octet rule (8 valence electrons) Extra e- Needs one more e- Valence shell Valence shell Full valence shells (8 e- )

Oxidation State - the charge that an atom forms

Determine the oxidation states of cation & anion STEPS TO WRITING IONIC FORMULAS for TYPE I BINARY COMPOUNDS Determine the oxidation states of cation & anion Balance the charges of your cation and anion so that the overall charge of the ionic compound is ZERO Write the symbol of the cation first and the anion second with the correct number subscript from balancing the charges (if the subscripts are equal, they cancel!)

Examples Cation Anion Cation Charge Anion Charge Formula Magnesium Chlorine Lithium Phosphorus Francium Oxygen Barium Nitrogen Cesium Selenium

STEPS TO WRITING IONIC NAMES for TYPE I BINARY COMPOUNDS Identify the cation and anion Name the cation by its element name Name the anion by changing the last part of its element name to “-ide” (ex. “Bromine” changes to “Bromide”) Write down the full name of the ionic compound by writing the cation name first and the anion name second Ca + Br = CaBr2 Mg + O = MgO Al + O = Al2O3 Be + N = Be3N2

Examples Cation Anion Cation Charge Anion Charge Formula Name Magnesium Chlorine Mg+2 Cl-1 MgCl2 Lithium Phosphorus Li+1 P-3 Li3P Francium Oxygen Fr+1 O-2 Fr2O Barium Nitrogen Ba+2 N-3 Ba3N2 Cesium Selenium Cs+1 Se-2 Cs2Se

Ag will always form a +1 charge and Zn will always form a +2 charge Transition metals (d-block) can form many different oxidation states. Therefore, their oxidation state will always be given. Exceptions! Ag will always form a +1 charge and Zn will always form a +2 charge

STEPS TO WRITING IONIC NAMES for TYPE II BINARY COMPOUNDS Same as Binary compounds except you must add the roman numerals in parentheses after the cation Examples: CuCl2 Fe2O3 Fe2O3 Iron (III) oxide CuCl Copper (I) chloride CuCl2 Copper (II) chloride PbS Lead (II) sulfide PbS2 Lead (IV) sulfide

POLYATOMIC IONS Group of atoms that together form a single ion with a positive or negative charge Always goes in parentheses if more than one

STEPS TO WRITING IONIC NAMES for TERNARY (POLYATOMIC) COMPOUNDS Follow the same steps for naming as before, using the given charge of the polyatomic, except you NEVER change the name of the polyatomic while naming! Na2SO4 sodium sulfate KH2PO4 potassium dihydrogen phosphate Fe(NO3)3 iron (III) nitrate Mn(OH)2 manganese (II) hydroxide Na2SO3 sodium sulfite Calcium hydroxide Ca(OH)2 Sodium phosphate Na3PO4 Ammonium dichromate (NH4)2Cr2O7 Cobalt (II) perchlorate Co(ClO4)2 Copper (II) nitrite Cu(NO2)2

Examples Cation Anion Cation Charge Anion Charge Formula Name Lithium Sulfate Ammonium hydroxide Magnesium Phosphorous Iron (III) Nitrate Zinc Chlorite