Practice Worksheet Ionic Compounds: Formulas and Names
Name ________________________
Period _____
Attached to these problems is a summary of how to name and write formulas of
compounds. If you aren’t sure how to work a problem, consult the indicated topic.
1.
Ion
K+
Fe2+
Ca2+
Co3+
Zn2+
Mg2+
Mn4+
2.
Name
Ion
O2S2HFC4N3I-
Name
Predict the formula of the ionic compound that would form between the ions given.
(The first one has been done for you).
(See Topic A for more help).
Cation
Ba2+
Mg2+
Rb+
Al3+
Na+
Ca2+
Sr2+
NH4+
K+
3.
(See Topic B for more help).
Name the following ions.
Anion
O2ClS2BrC4N3NO3Se2SO42-
Ionic Compound Formula
BaO
Knowing the charge on the anion, deduce the charge on the cation in the following.
(See Topic C and D for more help).
Formula
CuBr2
Na2SO4
Fe(OH)3
Ag3PO4
MnCO3
Cd(NO3)2
NiPO3
PbS
Al2(SO3)3
CoO
Fe(MnO4)2
Cation
Cu2+
Na+
Anion
BrSO42-
Name
copper (II) bromide
sodium sulfate
4.
a) Fill in the chart to indicate whether the combinations will describe an ionic compound or a
covalent (molecular) compound.
metal + nonmetal
nonmetal + nonmetal
NH4+ + other nonmetals
b) Determine whether each of the compounds is molecular or ionic.
Then supply the missing formula or name.
(See Topics A & D for more help).
Name the following ionic compounds:
1)
NH4Cl _____________________________________
2)
Fe(NO3)3 _____________________________________
3)
TiBr3 _____________________________________
4)
Cu3P _____________________________________
5)
SnSe2 _____________________________________
6)
GaAs _____________________________________
7)
Pb(SO4)2 _____________________________________
8)
Be(HCO3)2 _____________________________________
9)
Mn2(SO3)3 _____________________________________
10)
Al(CN)3 _____________________________________
Write the formulas for the following compounds:
11)
chromium (VI) phosphate _____________________________________
12)
vanadium (IV) carbonate _____________________________________
13)
tin (II) nitrite _____________________________________
14)
cobalt (III) oxide _____________________________________
15)
titanium (II) acetate _____________________________________
16)
vanadium (V) sulfide _____________________________________
17)
chromium (III) hydroxide _____________________________________
18)
lithium iodide_____________________________________
19)
lead (II) nitride _____________________________________
20
silver bromide _____________________________________
A.
Predicting Ionic Compound Formulas
 An ionic compound is neutral overall: (+) charge of cations + (-) charge of anions = 0

If the charges of the cation and anion don’t add up to be zero, then sum to zero or
“criss-cross” the charges (make sure you reduce the charges to lowest terms before you
criss-cross” them).
Cc+ Aaex.


B.
C.
Ba2+
Ca Ac
O2- → sum to zero → BaO
Fe3+
O2- → “criss-cross” → Fe2O3
The cation is written first.
When using a subscript for a polyatomic ion, put the entire polyatomic ion in ( ).
Naming Ions
Cation: Use element name “as is” or use
a Roman Numeral to specify charge
Anion: Replace end with “ide”
ex. Li+ is the “lithium” ion
ex. Mn2+ is “manganese(II)”
ex. C4- is carbide (carbon + ide)
Predicting Charge of cation from a Formula
Cations other than group I, group II, silver, cadmium, zinc and aluminum can have variable
charge. Since an ionic compound is neutral overall, the charge on the metal cation can be
determined based on the anion charge:
Total charge of cations + Total charge of anions = 0
D.
Ex. PbO: The charge on O is –2, so the charge on Pb must be +2.
FeBr3: The total anion charge is 3x(-1) = -3, so the charge on Fe must be +3.
(“Reverse” criss-cross!)
Naming Chemical Compounds
1. Ionic Compounds
a) Name the metal or the polyatomic ion “ammonium”.
b) Then the anion, ending in “ide” (or polyatomic ion name)
CaCl2
CaCO3
FeO
(NH4)2CO3
calcium chloride
calcium carbonate
iron(II) oxide
ammonium carbonate