1. Chapter 6 Compounds and Their Bonds
Naming and Writing Ionic Formulas

2. Naming Ionic Compounds with Two Elements
To name a compound that contains two elements,
identify the cation and anion.
name the cation first followed by the name of the anion.

3. Charges of Representative Elements
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4. Names of Some Common Ions
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5. Learning Check Complete the names of the following ions. Ba2+ Al3+ K+
_________ __________ _________
N3 O2 F
_________ __________ _________
P3 S2 Cl

6.
Part 2 of writing compounds

7. Solution Ba2+ Al3+ K+ barium aluminum potassium N3 O2 F
nitride oxide fluoride
P3 S2 Cl
phosphide sulfide chloride

8. Examples of Ionic Compounds with Two Elements
Formula Ions Name
cation anion
NaCl Na+ Cl- sodium chloride
K2S K S2- potassium sulfide
MgO Mg2+ O2- magnesium oxide
CaI2 Ca2+ I- calcium iodide
Al2O3 Al O2- aluminum oxide

9. Learning Check Write the names of the following compounds.
1) CaO ___________
2) KBr ___________
3) Al2O3 ___________
4) MgCl2 ___________

10. Solution Write the names of the following compounds:
1) CaO calcium oxide
2) KBr potassium bromide
3) Al2O3 aluminum oxide
4) MgCl2 magnesium chloride

11. Learning Check
Write the formulas and names for compounds of the following ions:
Br− S2− N3−
Na+
Al3+

12. Solution Na+ Al3+ NaBr sodium bromide Na2S sodium sulfide Na3N
Br− S2− N3−
Na+
Al3+
NaBr
sodium bromide
Na2S
sodium sulfide
Na3N
sodium nitride
AlBr3
aluminum bromide
Al2S3
aluminum sulfide
AlN
aluminum nitride

13. Transition Metals form Positive Ions
Most transition metals and Group 4(14) metals form 2 or more positive ions.
Zn2+, Ag+, and Cd2+ form only one ion.

14. Metals that form more than One Cation
The name of metals with two or more positive ions
(cations) use a Roman numeral to identify ionic charge.
Lead Pb lead(II)
Pb lead(IV)
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15. Naming Ionic Compounds with Variable Charge Metals
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16. Naming Variable Charge Metals
Transition metals with two different ions use a Roman numeral after the name of the metal to indicate ionic charge.

17. Naming FeCl2 To name FeCl2
1. Determine the charge of the cation using the charge
of the anion (Cl-).
Fe ion Cl- = Fe ion = 0
Fe ion = 2+
2. Name the cation by the element name and add a
Roman numeral in parenthesis to show its charge.
Fe2+ = iron(II)
3. Write the anion with an ide ending.
FeCl2 = iron(II) chloride

18. Naming Cr2O3
To name Cr2O3
1. Determine the charge of cation from the anion (O2-).
2 Cr ions O2- = 0
2 Cr ions (2-) = 0
2 Cr ions = 0
2 Cr ions = +6
Cr ion = = Cr3+
2. Name the cation by the element name and add a
Roman numeral in parenthesis to show its charge.
Cr3+ = chromium(III)
3. Write the anion with an ide ending.
chromium(III) oxide = Cr2O3

19. Learning Check Select the correct name for each. A. Fe2S3
1) iron sulfide
2) iron(II) sulfide
3) iron(III) sulfide
B. CuO
1) copper oxide
2) copper(I) oxide
3) copper(II) oxide

20. Solution Select the correct name for each. A. Fe2S3
3) iron (III) sulfide Fe3+ S2-
B. CuO
3) copper (II) oxide Cu2+ O2-

21. Guide to Writing Formulas from the Name
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Publishing as Benjamin Cummings

22. Writing Formulas Write a formula for potassium sulfide.
1. Identify the cation and anion.
potassium = K+
sulfide = S2−
2. Balance the charges.
K S2− K+
2(1+) + 2(1-) = 0
3. 2 K+ and 1 S2− = K2S

23. Writing Formulas Write a formula for iron(III) chloride.
1. Identify the cation and anion.
iron (III) = Fe3+ (III = charge of 3+)
chloride = Cl−
2. Balance the charges.
Fe Cl−
Cl− = (3+) + 3(1-) = 0
Cl−
3. 1 Fe3+ and 3 Cl− = FeCl3

24. Learning Check What is the correct formula for each of the following?
A. Copper(I) nitride
1) CuN 2) CuN3 3) Cu3N
B. Lead(IV) oxide
1) PbO2 2) PbO 3) Pb2O4

25. Solution The correct formula is A. Copper (I) nitride
3) Cu3N Need 3Cu+ and N3-
B. Lead (IV) oxide
1) PbO2 Need Pb4+ and 2O2-

26. Naming Cations and Anions
Monatomic Ions
Ions formed by one element
Cations
* for Group A elements – just write
element’s name
ex: calcium ion (Ca2+) = calcium
* for Group B elements – write element’s
name, then Roman numerals in
parentheses to denote charge
ex: Fe2+ = Iron (II) and Fe3+ = Iron (III)
Anions – drop the end of the element’s name & add “–ide” ending
ex: chlorine ion (Cl1-) = chloride
Cations – for those with only one charge, just write the element’s name; for transition metals with more than one possible charge, write the element’s name, followed by Roman numerals in parenthesis to denote the charge. Never write a Roman numeral after a monatomic cation that only has one possible charge
Anions – drop the end of the element’s name and add an –ide ending

27. Naming Cations and Anions
Polyatomic Ions
Ions formed by more than one type of element
Atoms of different elements held together by covalent bonds
Atoms always stay together and collectively have a single charge
Do not always have “-ide” ending
ex: NH41- = ammonium ion
CO32- = carbonate ion
Learn names, formulas, and charges of polyatomic ions!
Polyatomic ions are atoms of more than one type of element that stay together by covalent bonds and collectively have a single charge. Certain polyatomic ions are very common.
You should be able to write the polyatomic ions listed on your handout with their charges.

28. Naming Cations and Anions
Stop
Write the name or symbol w/ charge:
Potassium ion
Copper (II) ion
Chloride ion
Oxide ion
Ba2+
S2-
Au3+
Nitrite ion
Hydroxide ion
Phosphate ion
SO42-
CrO42-
ClO32-
Practice writing names and formulas of ions by writing the answers in your notebook.

29. Binary Ionic Compounds
Compounds composed of 2 different monatomic elements
To write binary formulas – write cation first, then anion
*criss-cross charges to determine how
many of each ion you need
*use subscripts to denote number of ions
ex: Ca2+ + Cl CaCl2
Na1+ + Cl NaCl
To name binary compounds – write name of cation first, then anion (-ide)
ex: CaCl2 = calcium chloride
Li2O = lithium oxide
Binary ionic compounds – are compounds composed of two different monatomic elements
To write formulas for binary ionic compounds, write the symbol for the cation first, followed by the anion. Cross-over the charges by using the absolute value of each ion’s charge as a subscript for the other ion.
If there is only one ion needed in a formula, a subscript is not needed (don’t write “1”)
To name binary ionic compounds, write the name of the cation first, followed by the name of the anion with the –ide ending

30. Ternary Ionic Compounds
Compounds containing at least one polyatomic ion; at least 3 different elements
To write ternary formulas: write cation first, then anion
*criss-cross charges to determine how
many of each ion you need
*use subscripts to denote number of ions
*must use parentheses around polyatomic if more than one is
needed!!!
ex: Na1+ + SO Na2SO3
Mg2+ + OH Mg(OH)2 [not same as MgOH2]
To name ternary compounds: write name of cation, then name of anion (not all end in “-ide”)
**be careful with transition metals (more than one charge)**
ex: CaCO3 = calcium carbonate
PbSO4 = lead (II) sulfate
Ag2CrO4 = silver chromate
Ternary ionic compounds – compounds containing at least one polyatomic ion; have at least 3 different elements
To write the formulas for ternary ionic compounds, use the same rules as for binary compounds
Except: use parentheses when more than one polyatomic ion is needed; use criss-cross method like binary
To name ternary ionic compounds, use the name rules as for binary compounds except remember that some polyatomic anions do not end in –ide. Be sure to note the exceptions.

31. Ionic Compounds
Stop
Write the name or the formula for the following compounds:
NaNO3
CaSO4
(NH4)2O
CuSO3
Fe(OH)3
NaF
Lithium sulfide
Iron (III) phosphide
Magnesium fluoride
Barium nitrate
Aluminum hydroxide
Potassium phosphate
Practice writing names and formulas of ionic compounds by writing the answers in your notebook.
Practice making ionic compounds!

32. Binary Molecular Compounds
Two nonmetals joined by covalent bonds
Use prefixes for naming
1 = mono-
2 = di-
3 = tri-
4 = tetra-
5 = penta-
6 = hexa-
7 = hepta-
8 = octa-
9 = nona-
10 = deca-
Binary Molecular Compounds are compounds made of nonmetals joined by covalent bonds
When binary molecular compounds are named, prefixes are used to denote how many atoms of each element are present

33. Binary Molecular Compounds
To name binary molecular compounds:
*first element gets a prefix if there is more than one
*second element ALWAYS gets prefix, and “-ide” ending
ex: N2O3 = dinitrogen trioxide
CO = carbon monoxide (not monocarbon)
If element begins with vowel and prefix ends in “a” or “o”, then drop last vowel on prefix to form the name
ex: Cl2O7 = dichlorine heptoxide (not heptaoxide)
To name binary molecular compounds
the first element gets a prefix if there is more than one atom of that element
the second element ALWAYS gets a prefix and ends in –ide.
If the element begins with a vowel and the prefix you add ends in an “a” or an “o”, drop the last vowel on the prefix to form the name

34. Write the name or formula for the following compounds:
Molecular Compounds
Stop
Write the name or formula for the following compounds:
P2O5
N2O
NO2
CBr4
CO2
tetraiodine nonoxide
sulfur hexafluoride
nitrogen trioxide
carbon tetrahydride
phosphorus trifluoride
Now practice writing the correct name or formula for the following molecular compounds in your notebook.