Types of Chemical Reactions
Honors Chemistry
Mr. Rivas
Types of Chemical Reactions
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2.
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4.
5.
6.
7.
Combustion Rxn
Synthesis (Combination) Rxn
Decomposition Rxn
Single Replacement Rxn
Double Replacement Rxn
Acid-Base Reactions
Redox Rxn
Combustion Rxn
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A substance reacts with O2 to form
compounds that contain oxygen atom(s)
General Form:
AB + O2  AO + BO
A + O2  AO
or
Combustion Rxn - Example
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The burning of charcoal is an example of a
combustion reaction
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C(s) + O2(g)  CO2(g)
Another important group of combustion
reactions is the burning of hydrocarbons
(gasoline is a mixture of hydrocarbons)
Hydrocarbons contain only carbon and
hydrogen atoms.
Three things are required to sustain a fire:
Combustion Rx - Hydrocarbons
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One important group of hydrocarbons are
the alkanes (hydrocarbons with only single
bonds)
They have the general formula:
CnH2n+2
Where n is the number of carbon atoms
Combustion Rx - Hydrocarbons
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The formula of a hydrocarbon with 4
carbons (n = 4) would then be:
C4H2x4+2  C4H10
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What would be the formula of a
hydrocarbon with 8 carbons?
C8H18
Combustion Rx - Hydrocarbons
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To name the hydrocarbons we use the
following prefixes:
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1
2
3
4
5
Meta
Eta
Propa
Buta
Penta
6
7
8
9
10
Hexa
Hepta
Octa
Nona
Deca
Combustion Rx - Hydrocarbons
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CH4
C 2H 6
C 3H 8
C4H10
C5H12
Etc.
Methane 
Ethane
Propane 
Butane 
Pentane
Natural Gas
BBQ balloon gas
Cigarette lighter
Combustion Rx - Hydrocarbons
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When hydrocarbons burn they produce:
Carbon dioxide and water.
The equation for the combustion of
methane is:
CH4 + 2O2  CO2 + 2H2O
Is this equation already balanced?
Can you balance this combustion reaction chemical equation?
Combustion Rx – Single elements
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Elements can also combust. Some rapidly:
2Mg + O2  2MgO
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Some slowly (Rusting)
4Fe + 3O2
 2Fe2O3
(Catalyst)
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These reactions can also be classified as
synthesis reactions.
Combustion Rxn - Exercises
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1)
2)
3)
4)
Write a balance equation for the
following combustion reaction:
Li + O2  Li2O
Ca + O2  CaO
CO + O2  CO2
Combustion of propane
Combustion Rxn - Exercises
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Answers:
+ O2  2Li2O
2) 2Ca + O2  2CaO
3) 2CO + O2  2CO2
4) C3H8 + 5O2  3CO2 + 4H2O
1) 4Li
Combustion Rxn - Exercises
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Answer questions Worksheet 9-2:
Combustion Reactions
The fire acts as the
activation energy to initiate
the combustion reaction
Synthesis Rxn
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In this reactions, two or more substances
are combined together to form a single
more complex compound.
General form:
A + B = AB
Synthesis Rxn - Example
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The reaction between chlorine gas and
sodium:
2Na(s) + Cl2(g)  2NaCl(s)
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Many combustion reactions can also be
classified as synthesis reactions:
2H2(g) + O2(g)  2H2O(g)
(This is an explosive reaction)
Synthesis Rxn - Example
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The formation of acid rain results from
synthesis reactions in the atmosphere:
2S(s) + 3O2  2SO3(g)
SO3 + H2O  H2SO4 (sulfuric acid)
This synthesis reaction started the
“Green Revolution”
N2(g) + 3H2(g)  2NH3(g) (ammonia)
Synthesis Rxn - Exercises
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Write a balance equation for the following
synthesis reactions:
+ I2  KI
2) Sr + O2  SrO
3) Na + S  Na2S
4) H2 + O2  H2O
1) K
Synthesis Rxn - Exercises
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1)
2)
3)
4)
ANSWERS:
2K + I2  2KI
2Sr + O2  2SrO
2Na + S  Na2S
2H2 + O2  2H2O
Decomposition Rxn
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A single compound produces two or more
substances.
General Form:
AB  A + B
Decomposition Rxn - Examples
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When heated, carbonates decompose to
form an oxide and carbon dioxide
CaCO3(s)  CaO(s) + CO2(g)
limestone
quicklime
CuCO3(s)  CuO(s) + CO2(g)
Decomposition Rxn - Examples
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Hydrogen peroxide slowly decomposes
into water and oxygen (light speeds up the
decomposition)
2H2O2(l)  2H2O(l) + O2(g)
When heated, sucrose (sugar)
decomposes into carbon and water
C12H22O11(s)  12C(s) + 11H2O(g)
Synthesis & Decomposition Rxn Exercises
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Answer questions Worksheet 9-2:
Part B: Synthesis & Decomposition
Reactions
Single Replacement Rxn
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A free element replaces a less active
element in a compound.
General Form:
A + BC  AC + B
(If A is more active than B)
Single Replacement Rxn - Examples
Hydrogen in hydrochloric acid is replaced by Zn,
a more active element.
Zn(S) + HCl(aq)  ZnCl2(aq) + H2(g)
 Bromine in sodium bromide is replaced by Cl, a
more active element.
Cl2(g) + NaBr(aq)  NaCl(aq) + Br l
 Copper in copper sulfate is replaced by Mg, a
more active element.
Mg(s) + CuSO4(aq)  MgSO4(aq) + Cu(S)
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The Activity Series of Metals
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Li Most Active
K
Ba
Sr
Ca
Na
Mg
Al
Mn
Zn
Fe
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Cd
Co
Ni
Sn
Pb
H
Cu
Ag
Hg
Au Least Active
Activity Series of the Halogens
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Fluorine Most active
Chlorine
Bromine
Iodine
Least active
Single Replacement Rxn - Exercises
1)
2)
3)
4)
Complete the following reaction. Enter
NR if no reaction is predicted.
Cu + AgNO3 
Fe + CuSO4 
Mg + CaSO4 
Br2 + KI

Single Replacement Rxn - Answers
1)
2)
3)
4)
Cu
Fe
Mg
Br2
+
+
+
+
2AgNO3 
CuSO4 
CaSO4 
2KI

Cu(NO3)2 + 2Ag
FeSO4 + Cu
NR
2KBr + I2
Single Replacement Rxn - Exercises
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Answer questions Worksheet 9-2:
Part C: Single Replacement Reactions
Double Replacement Rxn
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The positive ion of one compound
combines with the negative ion of the
other compound and vice versa.
General Form:
AB + CD  CB + AD
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The solubility rules determine if a double
replacement reaction will take place.
Double Replacement Rxn - Example
The silver ion of silver nitrate forms an
insoluble compound when it combines
with the chloride ion of sodium chloride
AgNO3(aq) + NaCl(aq)  NaNO3(aq) + AgCl(s)
 The lead(II) ion of lead(II) nitrate forms
and insoluble precipitate with the iodide
ion of potassium iodide.
Pb(NO3)2 + 2KI  PbI(s) + 2KNO3
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Solubility Rules
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NO3– All nitrates are soluble
Cl–
All chlorides are soluble except:
AgCl, Hg2Cl2, PbCl2, and CuCl
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SO42– All sulfates are soluble except:
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CO32– All carbonates are insoluble except:
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NH4+ and those alkaline metals
OH–
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BaSO4, PbSO4, SrSO4, CaSO4, and Ag2SO4
Alkaline metals, Ba(OH)2, Sr(OH)2, Ca(OH)2
S2–
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All hydroxides are insoluble except:
All sulfides are insoluble except:
Alkali, alkaline earth metals, and NH4+
Double Replacement Rxn - Exercises
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1)
2)
3)
4)
5)
Complete the following reaction indicate
NR if no reaction takes place:
Pb(NO3)2 + K2SO4 
SrBr2 + CuSO4 
MgCl2 + NH4NO3 
CaF2 + Li2CO3 
BeI2 + Li3PO4 
Double Replacement Rxn - Answers
Complete the following reaction indicate
NR if no reaction takes place:
1) Pb(NO3)2 + K2SO4  PbSO4 + 2KNO3
2) SrBr2 + CuSO4  SrSO4 + CuBr2
3) MgCl2 + NH4NO3  NR
4) CaF2 + Li2CO3  CaCO3 + 2LiF
5) 3BeI2 + 2K3PO4  Be3(PO4)2 + 6KI
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Double Replacement Rxn - Exercises
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Answer questions Worksheet 9-2:
Part C: Single Replacement Reactions
and
Part D: Double Replacement Reactions
Acid-Base Rxn
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According to the Brønsted-Lowry theory:
A base is any compound which can accept a
proton.
2. An acid is any compound which can donate a
proton.
1.
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In an acid-base reaction, an acid and a
base will react to form a salt and water.
Acid-Base Rxn – Example
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Hydrochloric acid (a proton donor) reacts
with sodium hydroxide (a proton acceptor)
to form sodium chloride (a salt) and water
HCl +
acid
NaOH  NaCl + H2O
base
salt
water
Redox Reaction
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A REDuction-OXidation reaction is one in
which an element is oxidized and another
one reduced.
Oxidation is the loss of electrons while
Reduction is the gain of electrons.
Many of the reactions that we have
covered are redox reactions.
Remember…
OIL RIG
Redox Reaction - Example
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The reaction of Magnesium and chlorine is
an example of redox reaction:
loses 2 electrons
Mg + Cl2  MgCl2
gains 2 electrons
Predicting Chemical Reactions
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Several factors such as temperature,
pressure, physical state, acidity, etc,
influence a chemical reaction.
The only way to determine the results of a
chemical reaction is by experimentation in
the lab.
Nevertheless, based on our classification
of the types of reactions, we can make an
educated guess.
Predicting chemical reactions
Predict the results of the following reactions:
1) K + I2 
2) C12H26 + O2 
3) Li + Pb(NO3)2 
4) MgCO3 
5) CuSO4 + NaOH 
6) LiOH + HCl 
Predicting chemical reactions
Predict the results of the following reactions:
1) 2K + I2  2KI
2) 2C12H26 + 37O2  24CO2 + 26H2O
3) 2Li + Pb(NO3)2  2LiNO3 + Pb
4) MgCO3  MgO + CO2
5) CuSO4 + 2NaOH  Na2SO4 + Cu(OH)2
6) LiOH + HCl  LiCl + H2O
Predicting chemical reactions
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Answer questions Worksheet 9-2:
Part E: Potpourri of reactions
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