IV. Naming Ionic Compounds Ch. 11 - Chemical Bonds IV. Naming Ionic Compounds (p. 314-320) Oxidation Number Ionic Names Ionic Formulas

A. Oxidation Number The charge on an ion. Indicates the # of e- gained/lost to become stable. 1+ 2+ 3+ 4+ 3- 2- 1-

B. Ionic Names Write the names of both elements, cation first. Change the anion’s ending to -ide. Write the names of polyatomic ions. For ions with variable oxidation #’s, write the ox. # in parentheses using Roman numerals. Overall charge = 0.

B. Ionic Names NaBr Na2CO3 sodium bromide FeCl3 sodium carbonate iron(III) chloride

C. Ionic Formulas Write each ion. Put the cation first. Overall charge must equal zero. If charges cancel, just write the symbols. If not, crisscross the charges to find subscripts. Use parentheses when more than one polyatomic ion is needed. Roman numerals indicate the oxidation #.

C. Ionic Formulas potassium chloride magnesium nitrate K+ Cl-  KCl copper(II) chloride K+ Cl-  KCl Mg2+ NO3-  Mg(NO3)2 Cu2+ Cl-  CuCl2

C. Ionic Formulas calcium oxide aluminum chlorate Ca2+ O2-  CaO iron(III) oxide Ca2+ O2-  CaO Al3+ ClO3-  Al(ClO3)3 Fe3+ O2-  Fe2O3