1. NAMING IONIC COMPOUNDS
There are a few general rules that apply when naming ionic compounds.
1. Most ionic compounds are also called salts.
2. Most ionic compounds exist as solids and many dissolve to form aqueous solutions.
3. An ionic compound is made up of a metal and a nonmetal; metals are located on the left side of the periodic table and nonmetals are on the right side.
4. The cation (positive ion) is written first followed by the anion (negative ion).
5. Before naming compounds, you should first memorize the individual cations and anions.

2. Nomenclature of binary ionic compounds
Name the metal then the root of the nonmetal + ide ending:
NaCl
Sodium chloride
BaCl2
Barium chloride
H2S
Hydrogen sulfide
Mg3N2
Magnesium nitride
NaF
Sodium fluoride
K2O
Potassium oxide
Notice that the cation is always mentioned first and then the anion.
Notice that the anion always ends in -ide
Notice that the number of elements in the compound is
not mentioned in the name.
Name the following ionic compounds:
Na2O K2S MgBr AlN Ba3As2
CaCl AgCl AlH ZnI Li3P

3. Nomenclature of binary ionic compounds
Answers:
Na2O = sodium oxide K2S = potassium sulfide
MgBr2 = magnesium bromide AlN = aluminum nitride
Ba3As2 = barium arsenide CaCl2 = calcium chloride
AgCl = silver chloride AlH3 = aluminum hydride
ZnI2 = zinc iodide Li3P = lithium phosphide

4. Nomenclature of binary ionic compounds
Some polyatomic anions that you must know:
NO3- = nitrate NO2- = nitrite
SO4 2 - = sulfate SO32- = sulfite
PO43- = phosphate PO32- = phosphite
CO32- = carbonate
HCO31- = hydrogen carbonate or bicarbonate
OH- = hydroxide CN- = cyanide
C2H3O2- = acetate C2O42- = oxalate

5. Nomenclature of binary ionic compounds
Naming salts composed of the polyatomic ions is the same as with the monatomic anions. Metal name then polyatomic name.
NaOH sodium hydroxide Ba(NO3)2 barium nitrate
H2SO4 hydrogen sulfate CsNO cesium nitrite
Sometimes there is a common name:
KHCO3 potassium hydrogen carbonate or potassium bicarbonate
Note: the polyatomic anions must be memorized.
Name the following ionic compounds:
NaHCO K2SO MgSO KCN H2PO4
Ca(OH)2 NH4NO3 Zn(NO3)2 Li3PO HNO3

6. Nomenclature of binary ionic compounds
Answers:
NaHCO = sodium hydrogen carbonate or sodium bicarbonate
K2SO = potassium sulfite
MgSO = magnesium sulfate
KCN = potassium cyanide
H2PO = hydrogen phosphate
Ca(OH) = calcium hydroxide
NH4NO = ammonium nitrate
Zn(NO3) = zinc nitrate
Li3PO = lithium phosphate
HNO = hydrogen nitrate

7. Nomenclature of binary ionic compounds
The previous examples only named type 1 or “fixed oxidation state” cations. When naming type 2 or “variable oxidation state” cations the rules change.
CuOH copper(I) hydroxide Fe(NO3)3 iron(III) nitrate
CuSO4 copper(II) sulfate Sn(NO2)4 tin(IV) nitrite
Sometimes a common name exists:
CuOH cuprous hydroxide Fe(NO3)3 ferric nitrate
When naming type 2 cations, the systematic method (IUPAC) requires the use of roman numerals after the elemental name to represent the oxidation state of the cation. The common name uses the –ic ending for the higher oxidation state and –ous ending for the lower oxidation state. Many times the old latin or greek name is used as the root.
Name the following ionic compounds:
CuHCO FeSO CuSO Cr(CN) Cr(PO4)2
Sn(OH)2 W(NO2)5 Ti(CO3) CoPO PbCl2

8. Nomenclature of binary ionic compounds
Answers:
CuHCO3 = copper(I) hydrogen carbonate or cuprous bicarbonate
FeSO3 = iron(II) sulfite or ferrous sulfite
CuSO4 = copper(II) sulfate or cupric sulfate
Cr(CN)3 = chromium(III) cyanide
Cr(PO4)2 = chromium (VI) phosphate
Sn(OH)2 = tin(II) hydroxide or stannous hydroxide
W(NO2)5 = tungsten(V) nitrite
Ti(CO3)2 = titanium(IV) carbonate
CoPO = cobalt(III) phosphate or cobaltic phosphate
PbCl = lead(II) chloride or plumbous chloride

9. PRACTICE PROBLEMS # 9a 1. KBr 2. BaO 3. Na2O
Below the formula, give the systematic name for the following compounds. If a common name exist, write it below the systematic name.
1. KBr 2. BaO 3. Na2O
4. BiF Cr2S Ti(NO3)4   
potassium bromide
Sodium oxide
Barium oxide
Bismuth (III) fluoride
Titanium (IV) nitrate
or titanic nitrate
Chromium (III) sulfide
The problem set continues on the next page.

10. GROUP STUDY PROBLEM # 9a 1. CaI2 2. Cs2S 3. Al2S3
Below the formula, give the systematic name for the following compounds. If a common name exist, write it below the systematic name.
1. CaI Cs2S Al2S3
4. CdI SnCl Zn(NO3)2
7. Fe2O3 8. Fe(OH) PbSO4   
The problem set continues on the next page.

11. Writing Chemical Formulas
1. The charge of the individual ions in a salt should add up to zero, the overall charge of the compound. For example NaCl is composed of Na+ ions and Cl- ions. For every one sodium ion you need one chloride ion (+1) + (-1) = 0
Ba2+ and N3- : You need 3 (+2 ) Barium ions to cancel out the 2 (-3) nitride ions so the overall charge of the compound is zero.
2. The individual ions should add up to the overall charge of the polyatomic ion.
What is the charge of Mn in MnO4-?
1 Mn + 4 O = -1 so 1(Mn) + 4 (-2) = -1 so Mn - 8 = -1
so Mn = +7

12. PRACTICE PROBLEMS #9b LiCl Al2S3 CuO Ca(HCO3)2 FeCl3 KNO2 KClO4
Below the name, write the formula for the following compounds.
Lithium chloride b) Aluminum sulfide e) Copper(II) oxide f)  
Iron(III) chloride i) Calcium bicarbonate l
Potassium nitrite Potassium perchlorate
Ammonium carbonates s )Iron(II) phosphate w)
Li + Cl -
LiCl
Al3+ S2-
Al2S3
CuO
Ca(HCO3)2
FeCl3
KNO2
KClO4
(NH4)2CO3
Fe3(PO4)2

13. GROUP STUDY PROBLEM #9b
Below the name, write the formula for the following compounds.
a) Barium oxide b) Sodium bromide  
c) Copper(I) oxide d) Iron(II) chloride
e) Potassium nitrite f) Calcium hydroxide
g) Silver nitrate h) Ammonium chloride
i) Lithium phosphate j) Sodium nitrite
k) Sodium bicarbonate l) Calcium Carbonate
m) Sodium sulfate n) Iron(III) hydroxide
o) Copper(II) hypochlorite p) Sodium sulfite