5 Types of
Chemical
Reactions
(continued)
1 Combustion
also called “burning”
representative
equation:
CxHyOz + O2
 CO2 + H2O
2 Synthesis
(also called combination or
composition)
means “putting together or
building up”
representative
equation:
A + B  AB
3
Decomposition
means “breaking down or
breaking apart”
is the opposite of a synthesis
reaction
representative
equation:
AB  A + B
Single replacement
(single displacement)
one element replaces
a similar element in a
compound
reactants:
an element and a
compound
products:
a different element
and a new
compound
representative equations:
A + BC 
B + AC
A is a metal.
representative equations:
Y + BC 
C + BY
Y is a non-metal. Usually
a halogen (group 17)
A metal element will try
to replace the cation of
the compound;
a nonmetal element will
try to replace the anion
of the compound.
Whether a single
replacement reaction will
occur can be predicted by the
activity series chart
An element can replace
elements below it.
Can Ba replace Zn? Y
Can Sn replace Pb? Y
Can Al replace Li? N
Can Fe replace Co? N
Can Cl replace Br?
Y
examples
__K + __NaCl  __KCl + __Na
__Li + __H2O  __LiOH + __H2
__Hg + __H2O  NR
__Cl2 + __CuBr2  __CuCl2 + __Br2
__AgNO3 + __Cu  __Ag + __Cu(NO3)2
__I2 + __NaBr 
_______ + _______
__Ca + __HCl  _______ +
H2
Double replacement
(double displacement)
cations and anions in two
compounds switch places
reactants:
two compounds,
usually ionic
compounds in aqueous
solutions
products:
For these reactions to take place, one
of the following must be a product:
• a precipitate
(a new compound that is not soluble)
see Solubility table
• Water (H2O)
• a gas (such as CO2 , H2S or NH3)
representative equation:
AB + CD 
AD + CB
examples
AgNO3 + NaCl  AgCl + NaNO3
CuS + HNO3  H2S + Cu(NO3)2
KOH + H2SO4  H2O + K2SO4
BaCl2 + Li2SO4 
Mg(NO3)2 + NaCl 