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-

0

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

FeCl3

• sodium bromide

• sodium carbonate

• iron(III) chloride

B. Ionic Names

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

copper(II) chloride

• K+ Cl KCl

• Mg2+ NO3 Mg(NO3)2

• Cu2+ Cl CuCl2

C. Ionic Formulas

calcium oxide

aluminum chlorate

iron(III) oxide

• Ca2+ O2 CaO

• Al3+ ClO3 Al(ClO3)3

• Fe3+ O2 Fe2O3

C. Ionic Formulas