1. Types of Chemical Reactions

2. Types of Chemical Reactions
Types of Chemical Reactions
Synthesis Decomposition Single Displacement Double Displacement Combustion Neutralization

3. Synthesis Reactions
In a synthesis reaction, two simple reactants combine to make a larger or more complex product
The general pattern for a synthesis reaction is
A + B→ AB
 A and B can be elements or compounds, AB is a compound.
Examples of synthesis reactions:
4 Al(s) O2(g) → 2 Al2O3(s)
2Mg+O2→2MgO
2Na+Cl2→2NaCl
CaO+ H2O→ Ca(OH)2
Hydrogen chloride + ammonia → ammonium chloride

4. Decomposition Reactions
Decomposition Reaction- A reaction in which a large or more complex molecule breaks down to form two (or more) simpler products -represented by this general equation: AB→ A + B AB is a compound, A and B can be elements or compounds

5. Examples of Decomposition Reactions:
2MgO→2Mg+O2
Ca(OH)2→ CaO+ H2O
H2SO4→SO3+ H2O
2H2O→2H2+ O2

6. You must be able to recognize what type of reaction depending on the reactants and product.
DON’T FORGET THAT SOME ELEMENTS EXIST AS DIATOMIC MOLECULES!!!
H2, O2, N2, F2, Cl2, Br2, I2

7. Single Displacement Reactions
Single Displacement Reaction-a reaction in which an element displaces another element in a compound, producing a new compound and a new element -one element takes the place of (displaces) another element in a compound -usually metals displace metals, and non metals displace non metals -represented by this general equation: A + BC → B + AC

8. Examples of Single Displacement Reactions: Mg+ 2AgNO3 -> 2Ag + Mg(NO3)2 (silver and magnesium are both metals, magnesium displaces silver) Br2 + CaI2→CaBr2 + I2 (Bromine displaces Iodine. Bromine and Iodine are both non-metals that have negative ionic charges) 3CuCl2 +2Al→ 2AlCl3 +3Cu (Aluminum, a metal, displaces copper, a metal) Mg +2HCl→ H2+ MgCl2 (Magnesium, a metal, displaces Hydrogen, acting as a metal)

9. Double Displacement Reactions
Double Displacement Reactions-a reaction that occurs when elements in different compounds displace each other or exchange places, producing 2 new compounds
-the METALS (cations) of two compounds exchange places
a precipitate, a gas or a molecular compound is usually formed
-represented by this general equation:
AB + CD → AD+ CB

10. Examples of Double Displacement Reactions:
2KI + Pb(NO3)2→PbI2+ 2KNO3
FeS + 2HCl→ H2S + FeCl2
Pb (NO3)2 + K2CrO4 → PbCrO4 + 2KNO3

11. COMBUSTION
Combustion reactions always involve molecular oxygen O2. Anytime anything burns (in the usual sense), it is a combustion reaction.
Combustion reactions almost always give off heat. For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced:

12. For example consider the combustion of methanol (rubbing alcohol):
Of course, not all combustion reactions release CO2 and water, e.g., the combustion of magnesium metal: