Transcript Chapter 5: Ionic Compounds


Ion: an atom or group of atoms that has a
charge as a result of losing or gaining one or
more electrons

Ca+ion: positively charged ion

Formed from a metal atom losing electrons
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
Anion: negatively charged ion
Formed from a nonmetal atom gaining
electrons
+1 +2
+/- 4
+3
-3
-1 0
-2
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Metals can have various charges, so you MUST specify
which one you have!
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The charge of a metal is indicated by a Roman Numeral.
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Exceptions: Groups 1 & 2, Silver (Ag), and Zinc (Zn) have
only one charge, so they do not get Roman numerals in
their names!
Examples:
1.) Copper (II) = Cu+2
2.) Iron (III) = Fe+2

Name the following transition metal ions:
1.) Cr+2
2.) Cr+3
3.) Mn+2
4.) Mn+3
5.) Pt+2
6.) Pt+4
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Name the following transition metal ions:
1.) Cr+2
Chromium (II)
2.) Cr+3
Chromium (III)
3.) Mn+2
Manganese (II)
4.) Mn+3
Manganese (III)
5.) Pt+2
Platinum (II)
6.) Pt+4
Platinum (IV)
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Determine if the following ions are cations
(metal) or anions (nonmetal):
1.) Calcium ion
2.) Nitrogen ion
3.) Potassium ion
4.) Bromine ion
5.) Oxygen ion
6.) Lead (IV) ion
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Determine if the following ions are cations or
anions:
1.) Calcium ion: cation
2.) Nitrogen ion: anion
3.) Potassium ion: cation
4.) Bromine ion: anion
5.) Oxygen ion: anion
6.) Lead (IV) ion: cation
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Element
Sodium
Fluorine
Magnesiu
m
Copper (II)
Symbol Metal or
Anion
and Nonmetal?
or
Charge
Cation?
Na+1
Metal
Cation
Element
Symbol Metal or
Anion
and Nonmetal?
or
Charge
Cation?
Sodium
Na+1
Metal
Cation
Fluorine
F-1
Nonmetal
Anion
Magnesiu
m
Mg+2
Metal
Cation
Copper (II)
Cu+2
Metal
Cation
Ion
S-2
Al+3
Fe+2
N-3
Ca+2
C-4
# of
protons
# of
electrons
Ion
S-2
Al+3
Fe+2
N-3
Ca+2
C-4
# of
protons
16
13
26
7
20
6
# of
electrons
18
10
24
10
18
10
Ion
Na+1
O-2
Zn+2
F-1
Mg+2
P-3
# of
protons
# of
electrons
Ion
Na+1
O-2
Zn+2
F-1
Mg+2
P-3
# of
protons
11
8
30
9
12
15
# of
electrons
10
10
28
10
10
18
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Octet Rule: Atoms lose or gain electrons to
match the valence electron configuration of a
noble gas.
Atoms gain or lose electrons because they
want to be more stable.
Full valence shells = stable atoms
1.) Determine number of electrons
2.) Write electron configuration
Example: Fluorine ion = F-1
Fluorine ion has 10 electrons
Electron configuration is 1s22s22p6
Neon also has 10 electrons and has the same
electron configuration, so F-1 and neon are
isoelectronic.
Determine the electron configuration of the
following ions and write which noble gas they
are isoelectronic with.
1.) Lithium ion
2.) Magnesium ion
3.) Calcium ion

Determine the electron configuration of the
following ions and write which noble gas they are
isoelectronic with.
1.) Lithium ion (2 electrons): 1s2
isoelectronic with helium
2.) Magnesium ion (10 electrons): 1s22s22p6
isoelectronic with neon
3.) Calcium ion (18 electrons): 1s22s22p63s23p6
isoelectronic with argon
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Transfer of electrons
Metal + Nonmetal
Ions come together due to electrostatic
attraction (opposites attract)
Determine if the following compounds are
ionic:
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NaCl : metal and nonmetal = ionic
CO2 : metal and nonmetal = not ionic
Determine if the following compounds are
ionic:
1.) CO
2.) MgCl2
3.) CaBr2
4.) H2O
5.) LiF
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Determine if the following compounds are
ionic:
1.) CO = nonmetal + nonmetal = not ionic
2.) MgCl2 = metal + nonmetal = ionic
3.) CaBr2 = metal + nonmetal = ionic
4.) H2O = metal + metal = not ionic
5.) LiF = metal + nonmental = ionic
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Na (1 valence e-) + Cl ( 7 valence e-)  Na+ ion (8 valence e-) + Cl- ion (8 valence e-):
Soidum (on the left) loses its one
valence electron to chlorine (on
the right)
The result is a positively charged
sodium ion (left) and a negatively
chorline atom (right). Both have
full outer shells!
http://www.visionlearning.com/library/module_viewer.php?mid=55
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Ionic compounds organize in
characteristic crystal lattice of
alternating positive and
negative ions.
Unit Cell: The smallest portion
of a crystal lattice that shows
the three-dimensional pattern
of the entire lattice.
Image from:
http://www.docbrown.info/page04/4_72bond2.h
tm
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When ionic bonds are formed, the energy that
is released is called the lattice energy.
Alternatively, you can think of it as the
amount of energy required to break the ionic
bonds of a compound.
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Sodium chloride (NaCl) dissolves in water: low
lattice energy
Magnesium oxide (MgO) does not dissolve in
water: high lattice energy
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Solid at room temperature
High boiling/melting points
Dissolve in water
Conduct electricity
Hard (the crystal is able to resist a large force
applied to it)
Brittle (applied force results in fracture, not
dents)
1.) Identify the state of matter
-should be a solid at room temperature
2.) Tap it
-will not break (hard) OR
-will fracture if it breaks (brittle)
3.) Heat it
-will only melt at high temperatures
4.) Shock it
-will conduct electricity
5.) Dissolve it in water
-will dissolve in water
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You tap the crystal and they shatter but still
retain their sharp edges.
You heat the substance and after 2-3
minutes of heating it does not melt.
It dissolves in water and conducts electricity.
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You tap the crystal and they shatter but still
retain their sharp edges.
Yes
You heat the substance and after 2-3
minutes of heating it does not melt.
It dissolves in water and conducts electricity.
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

You tap the crystal and they shatter but still
retain their sharp edges.
Yes
You heat the substance and after 2-3
minutes of heating it does not melt.
Yes
It dissolves in water and conducts electricity.
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

You tap the crystal and they shatter but still
retain their sharp edges.
Yes
You heat the substance and after 2-3
minutes of heating it does not melt.
Yes
It dissolves in water and conducts electricity.
Yes
Binary Ionic Compounds
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Metal + Nonmetal

Cation = positive charge

Anion = negative charge
1.
Write the symbol of the cation.
2.
Write the charge of the cation.
3.
Write the symbol of the anion.
4.
Write the charge of the anion.
5. Criss-cross the charges and write as
subscripts without the signs.
6. Rewrite the formula.
7. Reduce the subscripts.
8. Check your answer (the compound should
be neutral).
1.
Sodium oxide
2.
Aluminum sulfide
3.
Barium chloride
4.
Magnesium oxide
1.
Sodium oxide = Na2O
2.
Aluminum sulfide = Al2S3
3.
Barium chloride = BaCl2
4.
Magnesium oxide = MgO
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The metal will have its charge listed behind
its name as a roman numeral in parentheses.
Example:
Iron(III) bromide = FeBr3
Exceptions: Groups 1&2, Ag, and Zn don’t
have Roman numerals because they have only
one charge!
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Copper(II) chloride

Tin(IV) iodide
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Chromium(III) oxide
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Copper(II) chloride = CuCl2
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Tin(IV) iodide = SnI4
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Chromium(III) oxide = Cr2O3
Polyatomic Ionic Compounds
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An ion made up of one atom.
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A charged group of 2 or more covalently
bonded atoms.
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When writing the polyatomic ion, put
parentheses around the formula.
When criss-crossing the charges, drop the
subscript behind the parentheses.
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NEVER change any subscripts inside the
parenthesis.
1.
2.
3.
4.
5.
6.
7.
Sodium Phosphate
Calcium Nitrate
Magnesium Hydroxide
Potassium Sulfate
Calcium Acetate
Chromium (III) Nitrite
Magnesium Hydrogen Carbonate
1.
2.
3.
4.
5.
6.
7.
Sodium Phosphate: Na3PO4
Calcium Nitrate: Ca(NO3)2
Magnesium Hydroxide: Mg(OH) 2
Potassium Sulfate: K2SO4
Calcium Acetate: Ca(C2H3O2) 2
Chromium (III) Nitrite: Cr(NO2) 3
Magnesium Hydrogen Carbonate: Mg(HCO3)2
Binary Ionic Compounds
1.
2.
Write the name of the cation.
Write the name of the anion, change the
ending to –ide.
Examples: RbCl = rubidium chloride
K2S = potassium sulfide
1.
CaBr2
2.
MgS
3.
NaBr
4.
AlP
1.
CaBr2 = calcium bromide
2.
MgS = magnesium sulfide
3.
NaBr = sodium bromide
4.
AlP = aluminum phosphide
1.
2.
3.
Write the name of the cation.
Write the charge of the cation using a roman
numeral inside of parentheses.
Write the anion, change the ending to –ide.

Metals in Groups 1 and 2, Zinc and Silver are
the only metals that will not follow the stock
system because they only ever have one
charge.
1.
CuCl2 = copper(II) chloride
2.
FeCl2
3.
CuBr
4.
Cu2O
1.
CuCl2 = copper(II) chloride
2.
FeCl2 = iron(II) chloride
3.
CuBr = copper(I) bromide
4.
Cu2O = copper(I) oxide
Polyatomic Ionic Compounds
1.
Name the cation.
2.
Name the anion.
3.
4.
If the anion is monatomic, change the
ending to –ide.
Note: Only one polyatomic ion is a cation.
1.
2.
3.
4.
5.
Ca3(PO4) 2
NaOH
Ba(C2H3O2)2
MgSO4
(NH4)2S
1.
2.
3.
4.
5.
Ca3(PO4) 2 : Calcium Phosphate
NaOH : Sodium Hydroxide
Ba(C2H3O2)2 : Barium Acetate
MgSO4 : Magnesium Sulfate
(NH4)2S : Ammonium Sulfide