1. Types of Reactions

2. Chemical Equation Reminders
When not part of a compound, diatomic elements are written as:
H2 O2 F2 Br2 I2 N2 Cl2
Charges in a compound formula MUST cancel out to zero—i.e. the valance electrons must work out.
When balancing the overall equation, you can only change the COEFFICIENTS

3. Synthesis Reactions A + B → AB How do you tell?
In a synthesis reaction, two or more substances combine to form a new compound.
A + B → AB
How do you tell?
element + element → compound

4. Predicting the Products of Synthesis Reactions
Write compound formulas so charges cancel out!
Don’t worry about balancing the overall equation for now!
Na + Cl2  Na + Cl2  NaCl Al + S  Al + S  Al2S3

5. Decomposition Reaction
In a decomposition reaction a single compound is broken down to form two or more smaller compounds.
AB → A + B
How do you tell?
Compound → element + element

6. Predicting the Products of Decomposition Reactions
Write compound formulas so charges cancel out!
Don’t worry about balancing the overall equation for now!
NH3  NH3  N2 + H2 CaF CaF  Ca + F2

7. Combustion Reaction Carbon compound + O2 → CO2 + H2O
In a combustion reaction (burning), a carbon compound combines with oxygen and releases a large amount of energy in the form of light and heat.
Carbon compound + O2 → CO2 + H2O
The products of a combustion reaction are ALWAYS CO2 + H2O

8. Predicting the Products of Combustion Reactions
Write compound formulas so charges cancel out!
Don’t worry about balancing the overall equation for now!
CH4 + O2  CH4 + O2  CO2 + H2O C2H8 + O2  C2H8 + O2  CO2 + H2O

9. Types of Reactions Practice
Identify the following unbalanced reactions as synthesis, decomposition, or combustion. EXPLAIN YOUR CHOICE.
1. C10H22 + O2 → CO2 + H2O
2. MgO → Mg + O2
3. PCl3 + Cl2 → PCl5

10. Single Replacement Reaction
In a single replacement reaction, one element replaces a similar element in a compound.
A + BX → AX + B
How do you tell?
element + compound → element + compound

11. Predicting the Products of Single Replacement Reactions
Write compound formulas so charges cancel out!
Don’t worry about balancing the overall equation for now!
K + CuSO4  K + CuSO4  K2SO4 + Cu Cl2 + NaBr  Cl2 + NaBr  NaCl + Br2

12. Double Replacement Reaction
In a double replacement reaction, ions from two compounds in solution exchange places to produce two new compounds.
AB + CD → AD + CB
NaCl + AgNO3  AgCl + NaNO3
How do you tell?
compound + compound → compound + compound

13. Predicting the Products of Double Replacement Reactions
Write compound formulas so charges cancel out!
Don’t worry about balancing the overall equation for now!
Na2S + HCl  Na2S + HCl  NaCl + H2S Ca(NO3)2 + NaCl  Ca(NO3)2 + NaCl  NaNO3 + CaCl2

14. Types of Reactions Practice
Identify the following unbalanced reactions as synthesis, decomposition, single displacement, or double displacement. EXPLAIN YOUR CHOICE.
1. KOH + HBr → KBr + H2O
2. Mg + CO2 → MgO + C
3. PCl3 + Cl2 → PCl5

16. Carbon compound + O2 → CO2 + H2O
Type of Reaction
Identifying the type…
General Equation
two or more reactants combine to produce ONE compound
A + B → AB
Synthesis →
ONE compound is broken down to produce two or more compounds
AB → A + B
Decomposition →
element + compound produces element + compound
A + BX → AX + B
Single Displacement →
two compounds produce two compounds
AB + CD → AD + BC
Double Displacement →
burning - carbon compound combines with oxygen to release heat/energy
Carbon compound + O2 → CO2 + H2O
Combustion
ALWAYS THE PRODUCTS!

17. Types of Reaction Examples
Synthesis:
Mg + O2  MgO
Decomposition:
KBrO3  KBr + O2
Single Displacement:
Fe + CuSO4  Cu + FeSO4
Double Displacement:
NaCl + AgNO3  AgCl + NaNO3
Combustion:
C6H14 + O2 → CO2 + H2O