1. Notes #3: Types of Equations
WCHS Chemistry

2. = the energy needed to start a reaction
ACTIVATION ENERGY
= the energy needed to start a reaction
An “energy” barrier that has to be overcome for the reaction to proceed to products.
Can be any type of energy - thermal, mechanical, electrical, etc...

3. *IMPORTANT* The smaller the “hill”, the lower the activation energy!

4. = a chemical reaction with only 1 product
#1: SYNTHESIS
= a chemical reaction with only 1 product
Zn + S → ZnS
Reactants Products

5. = a chemical reaction with only 1 reactant
#2: DECOMPOSITION
= a chemical reaction with only 1 reactant
H2CO3 → CO H2O
Reactants Products

6. #3: SINGLE REPLACEMENT
= an element and a compound produce a new element and a new compound (1 ionic switch)
2Al + 3CuSO4 → 3Cu + Al2(SO4)3
Reactants Products

8. #4: DOUBLE REPLACEMENT
= 2 compounds react by exchanging ions and producing 2 new compounds (2 ionic switches)
Pb(NO3)2 + 2NaI → 2NaNO3 + PbI2
Reactants Products

9. = a hydrocarbon and oxygen react to produce carbon dioxide and water
#5: COMBUSTION
= a hydrocarbon and oxygen react to produce carbon dioxide and water
Hydrocarbon = CxHy *C & H ONLY!
CH4 + 2O2 → CO2 + 2H2O
Reactants Products