1. Naming Ionic Compounds
Ionic Nomenclature
Naming Ionic Compounds

2. Ionic Compounds Review
Ionic compounds are made of positive and negative ions.
Also known as “salts”.
Polyatomic ions are groups of atoms that behave as a single ion:
Examples:
CO3-2
CN-1
SO4-2

3. Naming Ionic Compounds
Two types of ionic compounds:
Binary, contains 2 elements
NaCl, MgBr2, Fe2O3
Ternary, contains 3 elements
Two of the elements are in a polyatomic ion
NaNO3, NH4Cl, Cr2(SO4)3

4. Naming Binary Ionic Compounds
Some metal ions have only one possible charge:
Group 1A metal ions all have +1 charge.
Group 2A metal ions all have +2 charge.
Ag+1, Zn+2, Cd+2, Al+3, Ga+3
For fixed charge cations, name as element.
Na+1 = sodium ion
Ca+2 = calcium ion
Ag+1 = silver ion
Ga+3 = gallium ion
Name anion as stem of element’s name followed by suffix –ide.
Cl-1 = chloride ion
S-2 = sulfide ion
N-3 = nitride ion

5. Fixed Charge Metal Ions
Be+2
Na+1
Mg+2
Al+3
K+1
Ca+2
Zn+2
Ga+3
Rb+1
Sr+2
Ag+1
Cd+2
Cs+1
Ba+2
Fr+1
Ra+2

6. Naming Binary Ionic Compounds
NaCl
KBr
MgF2
CaO
AgI
Al2S3
Zn3P2
sodium chloride
potassium bromide
magnesium fluoride
calcium oxide
silver iodide
aluminum sulfide
zinc phosphide

7. Naming Binary Ionic Compounds
Most metals can form multiple cations.
Iron can form Fe+2 ions or Fe+3 ions.
Copper can form Cu+1 ions or Cu+2 ions.
For variable charge cations, name as element w/ Roman numeral in ( ) to indicate charge.
Fe+2 = iron(II) ion
Fe+3 = iron(III) ion
Cu+1 = copper(I) ion
Cu+2 = copper(II) ion
Pb+2 = lead(II) ion
Pb+4 = lead(IV) ion

8. Variable Charge Metal Ions

9. Naming Binary Ionic Compounds
The compound must be electrically neutral.
Use the charge of the anion to figure out the charge of the metal.
Example: Fe2O3
(2 x Fe) + (3 x -2) = neutral
(2 x Fe) – 6 = neutral
(2 x Fe) = +6
Fe = +3
iron(III) oxide
Example: FeO
Fe + -2 = neutral
Fe = +2
iron(II) oxide

10. Naming Binary Ionic Compounds
FeCl2
Fe2Se3
CuBr
CuS
CrO
CrI3
PbF2
PbS2
iron(II) chloride
iron(III) selenide
copper(I) bromide
copper(II) sulfide
chromium(II) oxide
chromium(III) iodide
lead(II) fluoride
lead(IV) sulfide

11. Naming Ternary Ionic Compounds
Name metal as you would for a binary, with charge as a Roman numeral if necessary.
Name polyatomic anions as themselves. Know these:
CO3-2 = carbonate
NO3-1 = nitrate
PO4-3 = phosphate
SO4-2 = sulfate
OH-1 = hydroxide
ClO-1 = hypochlorite
ClO3-1 = chlorate
C2H3O2-1 = acetate
CH3COO-1 = acetate
CN-1 = cyanide

12. Naming Ternary Ionic Compounds
Only one polyatomic cation:
NH4+1 = ammonium
Name it, then name the anion properly.

13. Naming Ternary Ionic Compounds
LiNO3
Mg(OH)2
Fe2(SO4)3
Zn(C2H3O2)2
AlPO4
NH4Cl
Cr(CN)2
lithium nitrate
magnesium hydroxide
iron(III) sulfate
zinc acetate
aluminum phosphate
ammonium chloride
chromium(II) cyanide

14. Writing Formulas From Names
To write an ionic formula from a name, write the ions with their proper charges, then criss-cross.
Don’t forget that polyatomic ions need parentheses if there’s more than one of them.
Write the formula for iron(III) hydroxide
iron(III) = Fe+3
hydroxide = OH-1
iron(III) hydroxide  Fe+3 + OH-1  Fe(OH)3
Write the formula for potassium sulfate
potassium = K+1
sulfate = SO4-2
potassium sulfate  K+1 + SO4-2  K2SO4

15. Writing Formulas From Names
calcium carbonate 
sodium oxide 
aluminum cyanide 
potassium acetate 
copper(II) hydroxide 
gold(III) sulfide 
Ca+2 + CO3-2 
Na+ + O-2 
Al+3 + CN-1 
K+1 + C2H3O2-1 
Cu+2 + OH-1 
Au+3 + S-2 
CaCO3
Na2O
Al(CN)3
KC2H3O2
Cu(OH)2
Au2S3