# 4 Chemical Equations and Stoichiometry   ```Olympic High School  AP Chemistry
Name __________________________________
Period ___ Date ___/___/___
4  Chemical Equations and Stoichiometry
STUDY
I can:
Chemical Equations
Limiting Reactant Problems
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Give examples of products and reactants in a
chemical equation.
State that Antoine Lavoisier introduced the
law of conservation of matter.
Combustion
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State that combustion is another name for
burning.
Write an equation for a combustion reaction
given only the fuel that is burned.
Correctly label substances in an equation as
solid (s) , gas (g), liquid (l), or aqueous (aq)
Balancing Equations
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Recognize when an equation is balanced.
State that the formulas of reactants and
products should not be changed in order to
balance equations.
Stoichiometry Problems
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Use the stoichiometric factor ( of the
problem) to convert from moles of one
substance to moles of a different substance.
(i.e. In the equation: N2 + 3H2  2NH3,
3 mol H2  2 mol NH3)
Convert between the quantities of mass,
volume, molecules and moles using
dimensional analysis
(i.e. use 1 mol = 22.4 L, 1 mol = 6.02 x 1023
molecules, and 1 mol = gram molecular mass)
Show the units of molar mass as grams/mol or
g&middot;mol-1.
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LIST
Recognize that a problem with two “given
values” is a limiting reactant problem.
Determine the limiting reactant and excess
reactant in a problem.
Solve problems involving Limiting Reactants
Calculate how much excess chemical is left
over after a reaction.
Percent Yield Problems
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Use stoichiometry to calculate the theoretical
yield (mass of a product) in a problem.
State that actual yields are usually given in a
problem.
Use the theoretical yield and actual yield to
calculate the percent yield.
Chemical Analysis Problems
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Calculate the mass of each element in a given
compound given data such as the masses of
CO2 and H2O formed in a combustion
reaction.
Use mass and mole information to calculate
the empirical formula of an unknown
substance.
Use percent composition to equalize mass
and mole information derived from different
samples.
Continuous Variation Data
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Use “continuous variation” laboratory data to
determine the correct mole ratio of an
equation. (Micro Mole Rockets Lab)
Measuring Concentrations of Cmpds. in Solution
 Know the definition of molarity, M, as one
way to communicate concentration of solute.
 Know that the symbol [X] means the
concentration of X in moles/Liter.
 Be able to determine the concentration of ions
in an ionic compound.
For example, in 0.25 M AlCl3
[AlCl3] = 0.25 M [Al3+] = 0.25 M [Cl] =
0.75 M
 Use the molarity formula to calculate moles,
mass, volume, or molarity of a solution.
 Know that Volume x Molarity = moles of
solute. Dilution problems use ViMi = VfMf.
 Describe how to make a solution correctly.
Know what a volumetric flask is.
Stoichiometry of Reactions in Aqueous Solution
 Use molarity as another conversion factor to
solve stoichiometry problems.
 Know that titration is a technique called
quantitative chemical analysis because you
are measuring. It is also called volumetric
analysis (because you are measuring
volumes).
[Note: qualitative analysis involves no
measurements such as using solubility rules to
determine the identity of an unknown ionic
compound.]
 Understand the terms indicator, equivalence
point, standardization, and primary
standard.
 Know common indicators such as
phenolphthalein for titrations with strong
bases.
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Understand that a titration can be done with
an acid-base reaction or a redox reaction. In each
case, some sort of indicator must be used to tell
when equivalent amounts of reactants have been
mixed
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