1. Chapter 3 Stoichiometry

2. Stoichiometry – built on the law of conservation of mass (Antione Lavasier)
His ideas flowed from the work on the atomic theory – atoms: neither created nor destroyed in a chemical reaction.

3. Example: C3H8 + __O2  __CO2 + __H2O
Balancing Equations
You can only change coefficients!
Example: C3H8 + __O2  __CO2 + __H2O 5 3 4

4. Chemical reactions – some examples
Combustion: 
A + B ---> AB
8 Fe + S8 ---> 8 FeS
 Decomposition: 
AB ---> A + B
2 H2O ---> 2 H2 + O2
 Single Replacement:
A + BC ---> AC + B
Mg + 2 H2O ---> Mg(OH)2 + H2

5. Double Replacement: Acid-base: Combustion: AB + CD ---> AD + CB
Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3
 Acid-base:
HA + BOH ---> H2O + BA
HBr + NaOH ---> NaBr + H2O
 Combustion: 
C10H8 + 12 O2 ---> 10 CO2 + 4 H2O

6. 1)  NaOH + KNO3 --> NaNO3 + KOH
2)  CH4 + 2 O2 --> CO2 + 2 H2O
3)  2 Fe + 6 NaBr --> 2 FeBr3 + 6 Na
4)  CaSO4 + Mg(OH)2 --> Ca(OH)2 + MgSO4
5)  NH4OH + HBr --> H2O + NH4Br
6)  Pb + O2 --> PbO2
7)  Na2CO3 --> Na2O + CO2

7. 1)  double replacement  2)  combustion  3)  single replacement  4)  double replacement  5)  acid-base  6)  synthesis  7)  decomposition

8. Molecular Mass is total mass of all the atoms in a molecule
Formula mass is the mass of a unit cell in an ionic compound.

9. Percent Composition
AW stands for the atomic weight of the atom from the periodic table.
FW stands for the formula weight of the compound.

10. The mole Based on the work of Avogadro
Molar mass is the weight of one mole (or 6.02 x 1023 molecules)
1 mole Al x 1023 atoms
1 mole CaCl x 1023 molecules
The molar mass of elements is found by looking at the atomic mass of the element on the periodic table (for cmpds some all atoms)

11. Empirical Formula
Molecular Formula
Hydrates
Combustion Analysis

12. Stoichiometry Conversions- (gram to gram)

13. Limiting Reactants
The reactant that is consumed – all of it used up in the reaction
Chapter 3

14. Theoretical Yields
The amount of product predicted from stoichiometry taking into account limiting reagents is called the theoretical yield.
The percent yield relates the actual yield (amount of material recovered in the laboratory) to the theoretical yield:
Chapter 3