Naming Ionic Compounds #1
Name____________________ Period_________
When naming ionic compounds remember the following rules of the Stock Naming System:
Binary Ionic Compounds (two ions)
1. The cation (positively charged ion; Na+, Al3+) is always named first and the anion
(negatively charged ion; Cl-, O2-) second.
2. A monatomic (meaning one-atom) cation takes its name from the name of the
element. For example, Na+ is called sodium in the names of compounds containing this
ion.
3. A monatomic anion is named by taking the root of the element name and adding ide. Thus, the Cl- ion is called chloride, the S2- ion is called sulfide, and the O2- ion is
called oxide.
Ternary Ionic Compounds (more than two ions)
1. The cation of a transition metal is always named first (like any cation) and the anion
second.
2. A monatomic (meaning one-atom) cation takes its name from the name of the
element. For example, Cu+ is called Copper(I) and Cu2+ is called Copper(II) in the names
of compounds containing these ions. The number in parentheses is the charge of the
cation.
3. All transition metal cations, except Zn2+, Cd2+, and Ag+ (which always have the charges
shown on your handout), must show the oxidation number (charge) in
parentheses following the English spelling of the element, such as Iron(III), Copper(I), or
Vanadium(V), whenever a compound containing these ions, which have multiple
charges, is named.
4. Cations in Groups IIIA-VIA (including, Sn, Pb, Ga, Bi, etc.) also have multiple charges,
even though they are not transition metals. For all the metals in these groups (except
Al, which, of course, always has a +3 charge), include a parenthesis after the name, and
show its positive charge as a Roman numeral (Pb2+ is Lead(II) in names)
1
PART I:
Name the following ionic compounds using the Stock Naming System.
1. CaCO3
2. KCl
3. FeSO4
4. LiBr
5. MgCl2
6. FeCl3
7. Zn3(PO4)2
8. NH4NO3
9. Al(OH)3
10. CuC2H3O2
11. PbSO3
12. NaClO3
13. CaC2O4
14. Fe2O3
15. (NH4)3PO4
2
16. NaHSO4
17. Hg2Cl2
18. Mg(NO2)2
19. CuSO4
20. NaHCO3
21. NiBr3
22. Be(NO3)2
23. ZnSO4
24. AuCl3
25. KMnO4
PART II:
Write the ion symbols and oxidation numbers for each ion in the compound below its name.
Them, write the formulas of the following compounds on the line provided.
1. ammonium phosphate
2. iron (II) oxide
3. iron (III) oxide
4. calcium chloride
3
5. potassium nitrate
6. magnesium hydroxide
7. aluminum sulfate
8. copper (II) sulfate
9. lead (IV) chromate
10. potassium permanganate
11. zinc nitrate
12. aluminum sulfite
______
4
Chem I - Ionic Compound Formulas I #2 Name________________ Period_____
WHAT’S WRONG?
Each of the formulas for the ionic compounds is incorrect. Circle the incorrect
part of formula and write the correct formula in the space provided. Don’t forget
about the “criss-cross” method of writing formulas.
1. iron(II) carbonate
Fe2(CO3)
_______________
2. magnesium chlorate
Mg(ClO3)3
_______________
3. lithium bromide
Li2Br
_______________
4. manganese(II) nitride
Mn2N3
_______________
5. zinc nitrite
Zn(NO2)
_______________
6. potassium acetate
K2(C2H3O2)
_______________
7. lead(IV) nitrate
Pb(NO3)2
_______________
8. lead (II) cyanide
Pb(CN)4
_______________
9. cadmium (II) sulfate
Cd2(SO4)
_______________
10. tin (IV) fluoride
SnF
_______________
11. mercury(I) manganate
Hg(MnO4)2
_______________
12. tin(II) oxide
Sn2O
_______________
13. calcium bromide
CaBr
_______________
14. chromium(III) oxide
Cr3O2
_______________
15. gold(I) iodide
AuIO3
_______________
16. beryllium peroxide
BeO
_______________
5
17. cobalt(III) phosphide
Co3P2
_______________
18. ammonium nitrate
(NH)(NO3)
_______________
19. iron(III) dichromate
Fe2(CrO7)
_______________
20. cesium oxide
CsO
_______________
21. copper(II) sulfide
Cu(SO3)
_______________
22. silver phosphide
Ag2P
_______________
23. lead(II) hydroxide
PbOH2
_______________
24. lithium chloride
LiCl2
_______________
25. tin(IV) iodide
Sn4I
_______________
26. sodium fluoride
NaF3
_______________
27. chromium (II) oxide
Cr(II)O
_______________
28. Mercury (I) sulfide
M2S
_______________
29. silver phosphate
Ag3(PO4)2
_______________
30. cobalt(III) nitrite
Co(NO3)3
_______________
31. ammonium sulfate
(NH4)(SO4)
_______________
32. magnesium iodide
MgI
_______________
33. iron (III) oxide
FeO
_______________
34. calcium fluoride
CaF
_______________
35. aluminum chlorate
Al(ClO3)
_______________
6
Naming Molecular Compounds #3
(Binary)
Binary molecules are compounds containing only non-metal elements. These
compounds are always neutral (not ions which have charges), and consist of only
two elements (for more than two non-metal elements we will be naming them as
acids later in this unit). The prototypical compound is CO2, which is called carbon
dioxide.
1. The first element shown in the compound is named as the element
(e.g., for CO2, first element is "carbon")
2. The second element shown in the compound is named according to the anion
name, ending in -ide (e.g., for CO2, the second element is named "oxide")
3. The second element always carries a prefix indicating the number of times it
is present in the compound (e.g., for CO2, the second element (oxide) is present twice, so
it has the "di" prefix)
4. The amount of the first element is only shown, if it is present more than
once. It is assumed to be present only once, hence just the name of the
element. However, if it is present more than once, you must then specify the
number of times it is duplicated (di, tri, tetra, etc.)
The following prefixes are used to specify the number of times an element is present
in binary covalent compounds:
Prefixes (1-5)





1 — mono
2 — di
3 — tri
4 — tetra
5 — penta
Prefixes (6-10)





Examples using prefixes
6 — hexa
7 — hepta
8 — octa
9 — nona
10 — deca




7
CCl4 — carbon tetrachloride
P2O5 — diphosphorus pentoxide
N2O — dinitrogen monoxide
ICl3 — iodine trichloride
Name the following molecules.
1. CO2
2. CO
3. SO2
4. SO3
5. N2O
6. NO
7. N2O3
8. NO2
9. N2O4
10. N2O5
Write the correct formula for the following molecules.
11. Phosphorus trichloride
12. Phosphorus pentachloride
13. Nitrogen trihydride
14. Sulfur hexachloride
15. Diphosphorus pentachloride
16. Carbon tetrachloride
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17. Silicon dioxide
18. Carbon disulfide
19. Oxygen difluoride
20. Phosphorus tribromide
Molecular Compounds
Trivial Prefixes
Name the following molecular compounds using the Classic Suffix System. Then answer the prefix
trivia questions that follow.
Classic Suffix System



1 — mono
2 — di
3 — tri






4 — tetra
5 — penta
6 — hexa
7 — hepta
8 — octa
9 — nona

10 — deca
20. P2O3
31. P4O10
21. N2O4
32. ICl3
22. SO3
33. CI4
23. PBr5
34. CF2
24. As2O5
35. SeF6
25. As2S3
36. CBr4
26. GeCl2
37. NO
27. SCl2
38. N2O
28. CO
39. CO2
29. CCl4
40. What prefixes did you use the most?
__________________________________
30. CSe2
9
________
Chem I – Nomenclature Practice #4
(Compounds & Molecules)
Name____________________ Period_________
When writing the names and formulas, determine whether it is an ionic compound or molecule.
 Ionic Compounds: Contain a metal bonded to a nonmetal or polyatomic ion. Name the
metal first then the non-metal (-ide ending). If it has a transition metal with more than
one oxidation #, don’t forget the roman numerals in parenthesis stating the oxidation #.

Molecules: Contain nonmetals only. Use prefixes. Remember that the first element
will only contain a prefix if it has more than one atom. The second element will be
named as “prefix – root word – ide ending”.
Write the name for each.
Write the formula for each.
1. CuSO4
1. Magnesium oxide
2. SiBr4
2. Lead (II) nitrate
3. Cu2SO4
3. Sulfur trioxide
4. CaF
5. CCl4
4. Aluminum bicarbonate
6. Fe2O3
5. Carbon tetrabromide
7. SnCl2
6. Copper (II) chloride
8. KOH
9. Al2(SO4)3
7. Iron (II) hydroxide
10. CO
8. Chromium (II) carbonate
11. NS2
9. Iron (II) phosphate
12. FeS
10. Tin (IV) fluoride
13. Ni(NO2)2
10
11. Silver nitrate
12. Zinc sulfite
13. Phosphorus pentachloride
Write the formula for each.
Write the name for each.
14. Dinitrogen pentoxide
14. Sn(OH)4
15. NO2
15. Iron (III) nitrite
16. PCl3
16. Ammonium sulfide
17. AgC2H3O2
18. Ag2O2
17. Ammonium sulfite
19. FeCO3
18. Phosphorus pentachloride
20. Cs2O
21. ZnSO4
19. Phosphorus hexafluoride
22. Sn3(PO4)4
20. Lithium oxide
23. Na2SO4
24. SO3
21. Trinitrogen pentoxide
25. Al(OH)3
22. Copper (I) oxide
26. CsOH
27. N2O5
23. Tin (IV) nitride
24. Selenium tetrafluoride
25. Zinc acetate
26. Astatine pentasulfide
27. Strontium carbonate
________
11
Naming & Writing Formulas – Acids #5
(Binary & Ternary)
Acids are molecular compounds molecules that contain hydrogen
bonded to a nonmetal or to a group of polyatomic ions. Acids can
be either binary (consisting of only two elements) or ternary
Sulfurous acid (a ternary acid)
(consisting of more than two elements…usually polyatomic ions).
Even though acids are molecules that are covalently bonded, they have properties of ionic
compounds. Therefore the rules for naming and writing ionic compounds apply.
NAMING BINARY ACIDS:
 Hydro ______ ic acid.
Example: HCl = hydrochloric acid
NAMING TERNARY ACIDS:
1. Identify the polyatomic ion in the formula
2. Look for the ending and change:

“ate” changes to “ic”

“ite” changes to “ous”
Example: HPO4 = phosphoric acid (PO4 is phosphate therefore changed to “ic”)
3. Look for polyatomic ions that contain four oxygen possibilities (ClO3-1 and IO3-1)

Per_____ic
greatest # of oxygen atoms (ClO4-1)

_____ic
greater # of oxygen atoms (ClO3-1)

_____ous
smaller # of oxygen atoms (ClO2-1)

Hypo_____ous
smallest # of oxygen atoms (ClO-1)
Example: HClO = hypochlorous acid
WRITING BINARY ACID FORMULAS:
1. Write H+1
2. Write the second element’s symbol & oxidation number.
3. Criss Cross the charges to create a neutral formula.
Example: Hydrochloric acid =
H+ Cl- = HCl
12
WRITING TERNARY ACID FORMULAS:
1. Write H+1
2. Identify the polyatomic ion.
3. Change the endings by:

“ic” changes to “ate”

“ous” changes to “ite”
4. Write the polyatomic ions & oxidation number.
5. Criss Cross the charges to create a neutral formula.
Example: sulfuric acid =
H+ SO4-2 = H2S04
6. Look for prefixes such as “per” and “hypo”. They indicate the actual number of oxygen
atoms in the compound.
Example: perchloric acid =
H+ ClO4-1 = HCl04
Name the following acids:
40. HNO3
41. HCl
42. H2SO4
43. H2SO3
44. HC2H3O2
45. HBr
46. HNO2
47. H3PO4
48. H2S
49. H2CO3
13
Write the formulas of the following acids:
50. sulfuric acid
51. nitric acid
52. hydrochloric acid
53. acetic acid
54. hydrofluoric acid
55. phosphorous acid
56. carbonic acid
57. nitrous acid
58. phosphoric acid
59. hydrosulfuric acid
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Name_____________________________ Period_________
Naming Acids – Binary or Ternary #6
Write the formulas for the following acids.
 DEFINE acid as binary (only 2 elements) or ternary (more than two elements).
 Show your WORK (show elements with oxidation numbers).
 Write the chemical FORMULA (remember… formulas don’t have oxidation numbers)
ACIDS NAME
BINARY or TERNARY
WORK
Nitric acid
Chloric acid
Acetic acid
Hydrobromic acid
Sulfurous acid
Chlorous acid
Hydrochloric acid
Phosphoric acid
Nitrous acid
Hydrofluoric acid
Perchloric acid
Hydroiodic acid
Hypochlorous acid
Carbonic acid
Sulfuric acid
Citric acid
Bromic acid

NAME the following acids:
ACIDS FORMULA
BINARY or TERNARY
ACID NAME
H3PO4
HCl
HClO3
H2S
H2SO3
HC2H3O2
H2CO3
HF
HClO4
HI
HIO3
H2SO4
HNO3
HNO2
HClO
15
FORMULA