2. Classification of Chemical Reactions
Chemical reactions can be classified in one of two ways:
Based on how atoms are rearranged
Based on how energy/ heat is transferred
Vs.

3. where A and B may be either elements or compounds
SYNTHESIS REACTION
This is a reaction in which two or more elements or compounds combine to form a single product. This type of reaction follows the general equation
A + B  AB
where A and B may be either elements or compounds

4. where A and B may be either elements or compounds.
DECOMPOSITION REACTION
In this type of reaction a single reactant, a compound, breaks into two or more parts. Often these are the most difficult to predict.
Here is the general equation:
BC B + C
where A and B may be either elements or compounds.
2H2O2 2H2O +O2

5. F2 + MgBr2  Br2 + MgF2 Zn + CuCl2  Cu + ZnCl2
SINGLE REPLACEMENT REACTION
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 where A is a metal, or
A + BC  C + BA where A is a non-metal
F2 + MgBr2  Br2 + MgF2
Zn + CuCl2  Cu + ZnCl2

6. 2KI(aq) + Pb(NO3)2(aq)  2KNO3(aq) + PbI2(s)
DOUBLE REPLACEMENT REACTION
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
2KI(aq) + Pb(NO3)2(aq)  2KNO3(aq) + PbI2(s)
Note: “Metals” replace “metals” and non-metals replace non-metals

7. Special Double Replacement Reaction: Neutralization Reactions
In this type of reaction, an acid and a base react to form a salt and water.
The general equation for this type of reaction is:
HX + MOH  MX +H2O
Where M is a metal ion and X is a non-metal ion
HCl + NaOH  NaCl + H2O

8. CxHy + O2(g)  CO2(g) + H2O(l) or (g)
Combustion Reaction
In this type of reaction, a hydrocarbon is burned in the presence of oxygen gas to form carbon dioxide and water. Here is the general equation in the presence of plenty of oxygen:
CxHy + O2(g)  CO2(g) + H2O(l) or (g)
CH4 + O2  CO2 + 2H2O + energy
2C2H2 + 5O2  4CO2 + 2H2O + energy
C6H12O6 + 6O2  6CO2 + 6H2O + energy
Note: If combustion is inefficient (insufficient oxygen) then carbon monoxide is formed!
Acetylene torch

9. SUMMARY OF REACTIONS

10. Mixed Practice H2 + Cl2  HCl 3CuCl2 + 2Fe  2FeCl3 + 3Cu
State the type (Synthesis, Double Replacement, Single Replacement, Decomposition, Combustion & Neutralization)
H2 + Cl2  HCl
3CuCl2 + 2Fe  2FeCl3 + 3Cu
H2SO4 + 2KOH  K2SO4 + 2HOH
AgNO3 + NaCl  NaNO3 + AgCl
C5H12O2 + 7O2  5CO2 + 6H2O
2HgO  2Hg + O2
Synthesis
Single Replacement
Neutralization
Double Replacement
Combustion
Decomposition

11. Mixed Practice State the type, predict the products: BaCl2 + CaSO4 
Combustion & Neutralization
State the type, predict the products:
BaCl2 + CaSO4 
C6H O2 
Zn + CuSO4 
2Cs + Br2 
2H2O 
NaOH + H2S 
BaSO4 + CaCl2
6CO2 + 6H2O
ZnSO4 + Cu
2CsBr
2H2 + O2
NaS + H2O