1. Ionic Bonding
Chapter 20

2. A. Ionic Bonds Attraction between 2 oppositely charged ions
Ions - charged
atoms caused by
gain or loss of
electrons
formed by transferring e- from a metal to a nonmetal

3. A. Ionic Bonds
Cations (metals) first, anions written second (nonmetals or polyatomic ions)
Do NOT share electrons, one gains, and one loses

4. B. Ionic Compounds Network of ions, NOT a molecule
When melted or dissolved in water, ionic compounds conduct electricity
Ions are free to move, electric current is moving charges

5. C. Comparison Chart IONIC COVALENT transferred from metal to nonmetal
shared between nonmetals
Electrons
Melting
Point
high
low
Soluble in
Water
yes
usually not
yes (solution or liquid)
Conduct Electricity no
crystal lattice of ions, crystalline solids
molecules, odorous liquids & gases
Other
Properties

6. Naming Ionic Compounds Oxidation Number Ionic Names Ionic Formulas
Ch Ionic Bonds
Naming Ionic Compounds
Oxidation Number
Ionic Names
Ionic Formulas

7. A. Oxidation Number The charge on an ion
Indicates the # of e- gained/lost to become stable 1+ 2+ 3+ 4± 3- 2- 1-

8. B. Ionic Names For binary ionic compounds (2 elements)
Write the names of both elements, cation first
Change the anion’s ending to –ide
NO PREFIXES!!
NaCl = sodium chloride
CaCl2 = calcium chloride

9. B. Ionic Names NaBr Na2O AlCl3 sodium bromide sodium oxide
aluminum chloride

10. C. Ionic Formulas Write each ion including the oxidation number
Cation is written first
Oxidation numbers are written as superscripts
Overall charge must equal zero
If charges cancel, just write the symbols
If not, crisscross the charges to find subscripts

11. C. Ionic Formulas Calcium chloride Ca2+ Cl1-
charges do not cancel, must criss-cross charges
Rewrite as complete formula without oxidation numbers
CaCl2 1 2

12. C. Ionic Formulas potassium chloride magnesium nitride calcium oxide
K+ Cl-  KCl
Mg2+ N3-  Mg3N2
Ca2+ O2-  CaO

13. D. Polyatomic Ions A group of bonded atoms that have gained or lost e-
List on chart – need to know these for Quiz on Tuesday!!!
Parentheses are put around these when naming – (NH4)2SO4 = ammonium sulfate

14. D. Polyatomic Ions Naming compounds with PA ions:
For ionic compounds with more than 2 elements
Write the names of both ions, cation first
Write the full names of polyatomic ions (usually anion) – do not change the names

15. E. Ionic Formulas with PA Ions
calcium hydroxide
aluminum chlorate
magnesium carbonate
Ca2+ OH-  Ca(OH)2
Al3+ ClO3-  Al(ClO3)3
Mg2+ CO32-  MgCO3

16. E. Ionic Formula with PA ions
Write each ion including the oxidation number
Cation is written first
Overall charge must equal zero
If charges cancel, just write the symbols
If not, crisscross the charges to find subscripts
Use parentheses when more than one polyatomic ion is needed

17. E. Ionic Formulas with PA Ions
calcium hydroxide
aluminum chlorate
magnesium carbonate
Ca2+ OH-  Ca(OH)2
Al3+ ClO3-  Al(ClO3)3
Mg2+ CO32-  MgCO3

18. F. Ionic Compounds with Transition Metals
For transition metals, valence electrons and oxidation #’s are variable
Exceptions: Sn (tin), Pb (lead), Ag1+, and Zn2+
Roman numerals indicate the oxidation #
Chromium (III) = Cr3+
Iron (II) = Fe2+
Lead (IV) = Pb4+

19. G. Ionic Formulas with Transition Metals
Copper (II) bromide
Tin (IV) oxide
Manganese (II) chloride
Cu2+ + Br -  CuBr2
Sn4+ + O2-  Sn2O4  SnO2
Mn2+ + Cl -  MnCl2

20. H. Naming Ionic Compounds with Transition Metals
Write the ox. # in parentheses using Roman numerals. To determine oxidation #, know that overall charge of compound = 0
Cr2O3
CrO
3 x -2 = -6
2 x ___ = +6
Chromium (III) oxide -3
Formula:
Element: # atoms x charge = total charge
2 x -2 = -4
2 x ___ = +4
Chromium (II) oxide +2

21. H. Naming Ionic Compounds with Transition Metals
Shortcut that sometimes works – criss-cross backwards
CrCl2  Cr Cl2
chromium (II) chloride 2 1

22. I. Ionic Names with Transition Metals
Cr2(SO4)3
HgO
FeCl3
Chromium (III) sulfate
Mercury (II) oxide
iron(III) chloride