Section 8.2
Types of Chemical Reactions
Combination Reactions
Decomposition Reactions
Single-Replacement Reactions
Double-Replacement Reactions
Combustion Reactions
(complete and incomplete)
Please turn to page 3 in your Note Pack, and have
your Periodic Table available as a resource.
8.2 Types of Reactions
COMBINATION REACTIONS
A. What is a combination reaction?
(sometimes called a synthesis reaction or
composition reaction)
Two or more substances combine to form a
single substance.
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8.2 Types of Reactions
COMBINATION REACTIONS
B. Write a general equation for a combination
reaction:
A + B AB
There are some ways we can remember
these reactions and how to predict their
products.
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
2
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
1
When a metal combines with a nonmetal,
nonmetal use
their _____________ ___________ to figure out the
product.
(forms an ionic compound called a ___________)
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
1
When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the
product.
(forms an ionic compound called a ___________)
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8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
1
When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the
product.
(forms an ionic compound called a formula unit)
Ox. #’s are the possible charges an element CAN potentially
get (O = -2; Al = +3; Cu = +2 or +3)
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions… (Fill in examples)
1
When a metal combines with a nonmetal,
nonmetal use their
oxidation numbers to figure out the product.
(forms an ionic compound called a formula unit)
Example: Potassium metal reacts with Chlorine gas
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8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination reactions…
(Fill in examples)
1 When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the product.
(forms an ionic compound called a formula unit)
Example: Potassium metal reacts with Chlorine gas
K (s) + Cl2 (g) 8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination reactions…
(Fill in examples)
1 When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the product.
(forms an ionic compound called a formula unit)
Example: Potassium metal reacts with Chlorine gas
K (s) + Cl2 (g) K+ Cl-
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8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination reactions…
(Fill in examples)
1 When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the product.
(forms an ionic compound called a formula unit)
Example: Potassium metal reacts with Chlorine gas
K (s) + Cl2 (g) KCl
…but it’s not balanced yet.
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination reactions…
(Fill in examples)
1 When a metal combines with a nonmetal,
nonmetal use
their oxidation numbers to figure out the product.
(forms an ionic compound called a formula unit)
Example: Potassium metal reacts with Chlorine gas
2K (s) + Cl2 (g) 2KCl (s)
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8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
When a metal combines with a nonmetal,
nonmetal use their
oxidation numbers to figure out the product.
Next Example: Nickel (II) reacts with Oxygen gas
1
Ni + O2
8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
When a metal combines with a nonmetal,
nonmetal use their
oxidation numbers to figure out the product.
Next Example: Nickel (II) reacts with Oxygen gas
1
Ni + O2 Ni+2 + O-2
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8.2 Types of Reactions
COMBINATION REACTIONS
4 Good things to know about combination
reactions…
When a metal combines with a nonmetal,
nonmetal use their
oxidation numbers to figure out the product.
Next Example: Nickel (II) reacts with Oxygen gas
1
2Ni + O2 Ni+2 + O-2 2NiO
8.2 Types of Reactions
COMBINATION REACTIONS
•
When two nonmetals combine, you cannot figure
out the product based on oxidation numbers
There could be a number of possible
combinations for these molecules.
(forms a molecule and therefore we must rely on
observation to predict product)
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When two nonmetals combine, you cannot figure
out the product based on oxidation numbers
There could be a number of possible
combinations for these molecules.
(forms a molecule and therefore we must rely on
observation to predict product)
Example: Chlorine gas reacts with bromine gas to
produce trichlorine pentabromide solid.
8.2 Types of Reactions
COMBINATION REACTIONS
2
When two nonmetals combine, you cannot figure out
the product based on oxidation numbers
There could be a number of possible
combinations for these molecules.
(forms a molecule and therefore we must rely on
observation to predict product)
Example: Chlorine gas reacts with bromine gas to
produce trichlorine pentabromide solid.
Cl2 + Br2 9
8.2 Types of Reactions
COMBINATION REACTIONS
2
When two nonmetals combine, you cannot figure out
the product based on oxidation numbers
There could be a number of possible
combinations for these molecules.
(forms a molecule and therefore we must rely on
observation to predict product)
Example: Chlorine gas reacts with bromine gas to
produce trichlorine pentabromide solid.
Cl2 + Br2 Cl3Br5
(not balanced, yet)
8.2 Types of Reactions
COMBINATION REACTIONS
2
When two nonmetals combine, you cannot figure out
the product based on oxidation numbers
There could be a number of possible
combinations for these molecules.
(forms a molecule and therefore we must rely on
observation to predict product)
Example: Chlorine gas reacts with bromine gas to
produce trichlorine pentabromide solid.
3 Cl2 + 5 Br2 2 Cl3Br5
(now its balanced)
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with
water, it will produce an Acid.
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with
water, it will produce an Acid.
Examples might include:
N2O5
P2O5
SO3
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
Start by writing the H first
an acid)
(that’s what makes it
, and end with the O.
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
(start with the H and end with the O)
Example: Sulfur dioxide gas reacts with water
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with
water, it will produce an Acid.
(start with the H and end with the O)
Example: Sulfur dioxide gas reacts with
water
SO2 (g) + H2O (l)
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
(start with the H and end with the O)
Example: Sulfur dioxide gas reacts with water
SO2 (g) + H2O (l) H2SO3 (aq)
aq) , sulfurous acid
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
(start with the H and end with the O)
Next Example: Gaseous dinitrogen pentoxide gas
reacts with water
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
(start with the H and end with the O)
Next Example: Gaseous dinitrogen pentoxide gas
reacts with water
N2O5 (g) + H2O (l) ???
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a nonmetal oxide reacts with water, it
will produce an Acid.
(start with the H and end with the O)
Next Example: Gaseous dinitrogen pentoxide gas
reacts with water
N2O5 (g) + H2O (l) H2N2O6 = 2HNO3
Empirical formula
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a metal oxide reacts with water, it will
produce a Base.
Remember [H2O = H+ OH-]
Examples of metal oxides include:
Copper (II) oxide
CuO
Aluminum oxide
Al2O3
Sodium oxide
Na2O
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a metal oxide reacts with water, it will
produce a Base.
(start with the metal and end with hydroxide,
OH-)
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a metal oxide reacts with water, it will
produce a Base.
(start with the metal and end with hydroxide,
OH-)
Example: Sodium oxide reacts with water.
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8.2 Types of Reactions
COMBINATION REACTIONS
•
When a metal oxide reacts with water, it will
produce a Base.
(start with the metal and end with hydroxide,
OH-)
Example: Sodium oxide reacts with water.
Na2O (s) + H2O (l) ???
8.2 Types of Reactions
COMBINATION REACTIONS
•
When a metal oxide reacts with water, it will
produce a Base.
(start with the metal and end with hydroxide,
OH-)
Example: Sodium oxide reacts with water.
Na2O (s) + H2O (l) 2NaOH (aq)
aq)
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8.2 Types of Reactions
COMBINATION REACTIONS
Now its your turn…
With a neighbor, work through the following.
Practice Examples: Write the balanced
equations for the following combinations.
8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced
equations for the following combinations…
1 Beryllium metal reacts with oxygen gas
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8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
1 Beryllium metal reacts with oxygen gas
Be + O2 Be+2 + O-2 2BeO
Balanced, it looks like this…
2Be + O2 2BeO
8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
2 Gaseous dinitrogen pentoxide reacts with
water
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8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
2 Gaseous dinitrogen pentoxide reacts with
water
N2O5 + H2O H2N2O6 = 2HNO3
Empirical formula
8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
3 Nitrogen gas reacts with lumps of sulfur to
produce trinitrogen monosulfide.
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8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
3 Nitrogen gas reacts with lumps of sulfur to
produce trinitrogen monosulfide.
3N2
(g)
+ 2S (s) 2N3S
8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
4 Chunks of Calcium oxide is dropped into
water
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8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
4 Chunks of Calcium oxide is dropped into
water
CaO + H2O Ca(OH)2
8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
5 Aluminum metal rusts
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8.2 Types of Reactions
COMBINATION REACTIONS
Practice Examples: Write the balanced equations
for the following combinations…
5 Aluminum metal rusts
Al + O2 Al+3 + O-2 Al2O3
Balanced, it looks like this,
4Al + 3O2 2Al2O3
8.2 Types of Reactions
COMBINATION REACTIONS
Please use your notes, and really focus on
the Helpful Hints as you predict the
products of the Combination Reactions.
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