Types of
Chemical
Reactions
Synthesis & Decomposition
Single & Double
Displacement
April 17th, 2015
Prayer of the Day
Blessed are you, loving Father,
Ruler of the universe:
You have given us Your Son as Your Leader,
And have made us temples of Your Holy Spirit.
Fill our family with Your light and peace.
Have mercy on all who suffer,
And bring us to everlasting joy with You.
Father,
We bless Your Name for ever and ever.
Amen.
Learning Goals

What is a synthesis reaction? What is a decomposition
reaction? How do I differentiate between the two?

What is a single displacement reaction? What is a
double displacement reaction? How do I identify
when one is taking place?

How do I represent these new types of chemical
reactions using chemical formulas?

Can I predict how compounds will react? How?
Evidence of a Chemical
Change
A
precipitate (insoluble solid)
forms
 Gas
formation
 Change
 The
in odour
production of light and
heat
Types of Chemical Reactions
There are 4 main types of Chemical Reactions:
1. Synthesis Reactions
2. Decomposition Reactions
3. Single Displacement Reactions
4. Double Displacement Reactions
Synthesis Reaction
A
synthesis reaction is a chemical
reaction in which two or more reactants
combine to form a new product
Synthesis Reaction

* Reactants may be any combination of elements
and compounds, but the product will always be a
compound *
Example from the textbook:
The power that is created to allow a space shuttle to
blast off is created by a synthesis reaction:
Liquid Hydrogen + Liquid Oxygen  Water vapour
2H2 (l) + O2 (l)  2H2O (g)
REMEMBER
HOFBrINCl?
It is IMPORTANT to recall that oxygen and hydrogen exist as
diatomic molecules.
Hydrogen (H2),Oxygen (O2), Fluorine (F2), Bromine (Br2), Iodine
(I2) Nitrogen (N2), and Chlorine (Cl2) ….
“HOFBrINCl”
ALSO remember that these, all exist as gases, EXCEPT for
Bromine (liquid) and Iodine (solid)
** you’ll need to know this for when you’re indicating the
states of reactants and products in chemical equations!
Practice Problems 
Note: all of the products formed in these reactions are solids
3 Ca(s) +
42 K(s) +
12 Cs(s) +
N2(g) 
O2 (g) 
Ca3N2
2 K2O
P4 (s)  4 Cs3P
2 Al(s) + 3 F2(g)  2 AlF3
Decomposition Reactions
A
decomposition reaction is a chemical
reaction in which a compound breaks
down into two or more products
Decomposition Reaction

** The products may be any combination of
elements and compounds, but the reactant will
always be a compound. ** opposite of synthesis!
Example from the textbook:
Hydrogen gas is produced by the decomposition of
water
2H2O (l)  2H2(g) + O2 (g)
** this process is referred to as the electrolysis of water
+
=
+
=
=
+
Single Displacement Reactions
 In
a single displacement reaction, a
reactive element (a metal or a nonmetal) and a compound react to
produce another element and another
compound. Therefore, it is a chemical
reaction in which an element takes the
place of another element in a
compound.
Single Displacement Reactions
If something better (more reactive) comes along, it’ll bump out the
other one:
Single Displacement Reactions
Activity Series
 An
activity series is a list of elements
organized according to their chemical
reactivity. The most reactive element is at
the top, and the least reactive is at the
bottom.

A more reactive metal will DISPLACE (or
REPLACE)a metal in a compound that is
below it in the activity series.
Activity Series
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
Because
hydrogen ions
can be positively
charged, metals
can take the
place of
hydrogen in
compounds.
Hydrogen will be
displaced as H2
(Hydrogen gas)
Practice on your
worksheet!
Double Displacement
Reactions
A
double displacement reaction is a
chemical reaction in which the positive
ions of two compounds change places
and form two new compounds.
Calcium bromide + Silver nitrate 
Calcium nitrate + Silver bromide
* Metal first!
CaBr2 + Ag(NO3)  Ca(NO3)2 + AgBr
Practice Sheets
 Do
 I’ll
these for homework 
check that out tomorrow, so do it, and
if you don’t understand something, put a
star beside it so you can remember to ask
for help!