The document describes 6 main types of chemical reactions: 1. Synthesis reactions involve the combining of two or more reactants to form a single product. 2. Decomposition reactions involve the breaking down of a single reactant into two or more products. 3. Single displacement reactions involve an element replacing another element in a compound. 4. Double displacement reactions involve the exchange of elements between two reactants to form two new compounds. 5. Neutralization reactions involve an acid and a base reacting to form a salt and water. 6. Combustion reactions involve a fuel reacting with oxygen to produce energy and oxides.

1. Movie: types of chemical reactions:
http://www.youtube.com/watch?v=i-HHvx1VC_8

2. Identify, give evidence for, predict products of,
and classify the following types of chemical
reactions:
1. Synthesis (combination)
2. Decomposition
3. Single Replacement
4. Double Replacement
5. Neutralization (acid/base)
6. Combustion

3.  Synthesis
 Decomposition
 Neutralization
 Single displacement
 Double displacement
 Combustion

4. A chemical change: any change in which a
new substance is formed.
Evidence of a Chemical Change:
 Release of energy as heat
 Release of energy as light
 Change in colour
 Formation of a gas
 Change in odour…

5. 1.
Neutralization: Acid(H) + Base(OH)  salt +
H(OH)
2. Combustion: AB + oxygen  CO2 + H2O
3. Synthesis: A + B  AB
4. Decomposition: AB  A + B
5. Single displacement: A + BC  AC + B
6. Double displacement: AB + CD  AD + CB

6. Synthesis reactions are also known as FORMATION
reactions.
Two or more reactants (usually elements) join to form a
compound.
–A + B  AB
where A and B represent elements
– The elements may form ionic compounds,
like…
– Sodium metal and chlorine gas combine
to form sodium chloride.
– 2Na + Cl2  2NaCl
Sodium added
to chlorine gas

8. TYPES: SYNTHESIS
Example C + O2
C + O O

O C O
C
C
O O
C
C
O O
C
C C C C C C CC
C
General:
A + B  AB

9. OTHER EXAMPLES…
1.
Elements that form ionic compounds:
Magnesium metal reacts with oxygen gas to
form magnesium oxide.
•2Mg + O2  2MgO
2. Elements that form covalent compounds:
Nitrogen gas and oxygen gas join to form nitrogen monoxide.
•2N2 + O2  2N2O
SYNTHESIS REACTION (iron + sulphur):
http://www.youtube.com/watch?v=A5H6DVe5FAI

10. • Decomposition reactions are the opposite of synthesis
reactions.
–A compounds breaks down into two or more products
(often elements).
–AB  A + B
where A and B represent elements
1. Ionic compounds may decompose to produce elements,
like the following:
• Table salt, sodium chloride, can be broken down into
sodium metal and chlorine gas by melting salt at 800ºC
and running electricity through it.
• 2NaCl  2Na + Cl2

12. TYPES: DECOMPOSITION
Example: NaCl
Cl Na

General:
Cl
+
Na
AB  A + B

13. TYPES: DECOMPOSITION
Example 2HgO
O Hg

O Hg
General:
Hg
+
O O
Hg
AB  A + B

14. 2. Covalent compounds may decompose into
elements, like the following:
By running electricity through water, the water
molecules decompose into hydrogen and oxygen
gases.
2H2O  2H2 + O2
DECOMPOSITION
REACTION:
http://www.youtube.com/wa
tch?v=NddwtXEA_Ak

15. Single replacement reactions replace one element
from a compound with another element.
 A compound and an element react, and the element
switches places with part of the original compound.
A + BC  B + AC
metal, or
where A is a
A + BC  C + BA where A is a
non-metal

17. TYPES: SINGLE DISPLACEMENT
Example: Zn + CuCl2
Cu
Cl
+
Cl
General:
Zn

Zn
Cl
+ Cu
Cl
AB + C  AC + B

18. 1. When A is a metal:
Aluminum foil in a solution of copper(II)
chloride produces solid copper and
aluminum chloride.
2Al + 3CuCl2  3Cu + 2AlCl3
2. When A is a non-metal:
When fluorine is bubbled through a
sodium iodide solution, iodine and sodium
fluoride are produced.
Fl2 + 2NaI  I2 + 2NaF
SINGLE REPLACEMENT:
http://www.youtube.com/watch?v=hKtynbVtMKc

19. Double replacement reactions swap elements between 2
compounds that react together to form two new
compounds.
 Two compounds react, with elements switching places
between the original compounds.
AB + CD  AD + CB

21. TYPES: DOUBLE DISPLACEMENT
Example: MgO + CaS
Mg
+
O
General:
Ca
S

Mg
S
+
Ca
O
AB + CD  AD + CB

22. Two solutions react to form a precipitate (solid) and
another solution.
Ionic solution + ionic solution  ionic solution + ionic solid.
CD  AD + CB
AB +
 When potassium chromate and silver nitrate react,
they form a red precipitate, silver chromate, in a
solution of potassium nitrate.
K2CrO4 + 2AgNO3  Ag2CrO4 +
2KNO3
DOUBLE REPLACEMENT:
http://www.youtube.com/watch?v=opY3FLrPTa4 silver chromate

23. • Neutralization reactions occur when an acid (most compounds
starting with H) and a base (most compounds ending in OH)
react to form a salt and water.
• Neutralization reactions are a type of double replacement.
•Acid + base  salt + water
HX + MOH  MX + H2O
where X and M are elements

24. 1. Sulfuric acid is used to neutralize calcium hydroxide:
H2SO4 + Ca(OH) 2  CaSO4 + 2H2O
2. Phosphoric acid helps to neutralize the compounds that cause rust,
such as iron(II) hydroxide.
H3PO4 + 3Fe(OH)2  Fe3(PO4)2 +
6H2O
NEUTRALIZATION:
http://www.youtube.com/watch?v=_P5hGzA6Vb0

25. Combustion reactions occur when a compound or element
react with oxygen to release energy and produce an
oxide.
 Also sometimes referred to as hydrocarbon combustion.
CXHY + O2  CO2 + H2O
where X and Y represent integers
METHANOL + oxygen:
http://www.youtube.com/watch?v=98JuJ-G1qXY&feature=related

26. 1. Natural gas (methane) is burned in furnaces to heat
homes.
CH4 + O2  CO2 + 2H2O + energy
2. An acetylene torch is used to weld metals together.
2C2H2 + 5O2  4CO2 + 2H2O +
energy
3. Carbohydrates like glucose combine with oxygen in our
body to release energy.
C6H12O6 + 6O2  6CO2 + 6H2O +
energy
Acetylene torch

27. MOVIE TO REVIEW:
http://www.bcscience.com/bc10/pgs/videos_013_chemical_reactions.html