Reaction Types
Chemistry
Dr. May
Single Displacement Reaction

A Compound and an element form a
compound and an element

C + AB  CB + A

Zn + 2 HCl 
ZnCl2 + H2 
May I Have This Dance ?

Dancer C steps in to dance with B replacing A

C + AB  CB + A
Single Displacement Reactions

Zn
+
2 HCl

ZnCl2
+

2 Al +
6 HCl

2 AlCl3
+ 3 H2 

Mg
+
2 HNO3 
Mg(NO3)2 +
H2 

Zn
+
H2SO4 
ZnSO4
H2 
+
H2 
Single Displacement Reactions

Cu
+ 2 AgNO3 
Cu(NO3)2 +
2 Ag

2 Fe + 2 CuSO4 
Fe2(SO4)3 +
2 Cu

3 Al + 2 CuCl2 
3 AlCl3
+
2 Cu

Mg
CuSO4 
MgSO4
+
Cu
+
Will React
With Acid
Activity Series
Most Active
HCl + Zn  ZnCl2 + H2 
Li, K, Ca, Na, Mg, Al, Zn, Cr, Fe,Ni, Sn, Pb
H
Acid
Cu, Hg, Ag, Pt, Au
Least Active
Will Not React
With Acid
Driving Force
A single displacement reaction is driven by
the electron affinity of the elements
2 AgNO3 + Cu  Cu(NO3)2 + 2 Ag
2 Ag+1 + 2 NO31 + Cu0  Cu+2 + 2 NO31 + 2 Ag0
Silver wants electrons more than copper
2 Ag+1 + Cu0  Cu+2 + 2 Ag0
Copper is oxidized and silver is reduced
Double Displacement Reaction

Two compounds form two different
compounds

AB + CD  AD + CB

HCl
+ KOH 
KCl
+ HOH
Let’s Trade Partners

Dancer A takes D and dancer C takes B
C

AB + CD  B + D  CB + AD
A
Double Displacement Reactions

HCl

NaCl
+
HOH

2 HCl + Ca(OH)2 
CaCl2
+
2 HOH

2 KI + Pb(NO3)2 
PbI2  + 2 KNO3

NH4Cl
+
NaOH
+
KOH 
KCl
+
NH4OH
Driving Double Displacement

Formation of a precipitate (AgCl )

Formation of a non-ionized material (H2O)

Formation of a gas (CO2 )
Formation of a precipitate
AgNO3 + KCl  AgCl  + KNO3
Silver chloride precipitates from solution and
drives the reaction to the right
Formation of a non-ionized material
HNO3 + KOH  HOH + KNO3
Water is covalently bonded and does not
ionize, driving the reaction to the right.
Formation Of A Gas
2 HNO3 + K2CO3  2 KNO3 + H2CO3
HOH + CO2 
Carbonic Acid is unstable and decomposes to
form water and carbon dioxide, driving the
reaction to the right
No Reaction
If there is no driving force,
 Then there is no reaction

NaCl + KNO3  No Reaction
Na+1 + Cl1 + K+1 + NO31  Na+1 + Cl1 + K+1 + NO31
Synthesis Reaction

Two or more materials combine to form a
new compound

A + B

2 H2 +

O2
AB

2 H 2O
Materials Combine

Two or more materials combine to form a
new compound
Hydrogen is oxidized
(Loses electrons)

2 H2 +
O2

2 H2O
Oxygen is reduced
(Gains electrons)
Synthesis Reactions

Na
+
Cl2

2 NaCl

N2
+
3 H2

2 NH3 

4 Na +
O2

2 Na2O

4 Fe +
3 O2

2 Fe2O3

Oxidized

Reduced

New Compound
Decomposition Reactions

A compound breaks apart to form two or
more new materials

AB

2 KClO3  2 KCl
 A + B
+
3 O2
Compounds Break Apart

A compound breaks apart to form two or
more new materials

2 KClO3  2 KCl
+
3 O2
Decomposition Reactions

H2CO3

H2O
+
CO2 

NH4OH

H2O
+
NH3 

H2O

H2 
+
O2 

CaCO3

CaO
+
CO2 

H2SO4
H2O
+
SO3 

Combustion Reactions

A hydrocarbon compound combines with
oxygen to form CO2 plus H2O

CxHy + O2  CO2 + H2O

C3H8 + 5 O2  3 CO2 + 4 H2O
Green House Gas
Burning gasoline gives CO2 and H2O

C7H16 + 11 O2 
7 CO2 + 8 H2O
Combustion Reactions

CH4
+
2 O2 
CO2
+
2 H2O
4 CO2
+
6 H2O
3 CO2
+
4 H2O
8 CO2
+
10 H2O
5 CO2
+ 6 H2O
Natural Gas

2 C2H6 +
7 O2 
Propane

C3H8
+
5 O2 
Butane

2 C4H10 +
13 O2 
Jet Fuel

C5H12
+
8 O2 
Hydrocarbon Vs. Hydrogen Fuel
2 H2 +
O2

2 H2O

Water is the only product
C5H12
+
8 O2  5 CO2 + 6 H2O

Forms lots of greenhouse gas
The End

This presentation was created for the benefit
of our students by the Science Department
at Howard High School of Technology

Please send suggestions and comments to
rmay@nccvt.k12.de.us