WHAT IS STOICHIOMETRY?
Stoichiometry is the study of the quantitative relationships between the
amounts of reactants used and the products formed by a chemical
reaction
Stoichiometry is based on the Law of Conservation of Mass
 Mass of Reactants = Mass of Products
WHAT IS STOICHIOMETRY USED FOR?
Stoichiometry is used to tell chemists:
1.
How much product will be produced
2.
How much reactant is needed to make a product
STOICHIOMETRY AND THE BALANCED EQUATION
Coefficients in a balanced chemical equation can tell us:
1.
The # of individual particles: (atoms, molecules, or FUN)
2.
The # of moles of particles
3.
The mass of reactants and products (Found using the molar mass
(MM) of the compounds)
EXAMPLE
Balance the Following Equation:
___ Fe(s) + ___ O2(g) ___ Fe2O3(s)
EXAMPLE ANSWER
Balance the Following Equation:
4 Fe(s) + 3 O2(g)  2 Fe2O3(s)
FILL IN THE TABLE
Fill in the table below:
Reactants
Name:
Iron
+
Formula:
Fe
+
Products
Oxygen Gas
O2


Iron (III) Oxide
Fe2O3
_____atoms of Fe
+
_____ molecules O2

_____ formula units Fe2O3
_____ moles Fe
+
_____ moles O2

_____ moles Fe2O3
+
_____ grams O2

_____ grams Fe2O3
____ grams reactants

_____ grams products
_____ grams Fe
MOLE RATIO
(COEFFICIENT RATIO)
Mole Ratio (coefficient ratio) – the ratio between the numbers of moles of
any 2 substances in a balanced chemical equation
Ex. Balance the following equation and determine all mole ratios:
1.
____ N2(g) + ____ H2(g)  ____ NH3(g)
2. ____ Fe(s) + ____ H2O(l)  ____ Fe3O4(s) + ____ H2(g)