AP Chem Cumulative Review
Stoichiometry
Composition Stoichiometry
1. What information can be derived from a chemical
formula of an ionic compound versus a molecular
compound?
2. What three conversion factors and in what order
would you use them to convert the mass of a
compound into atoms of a particular element in
that compound? Calculate the number of
hydrogen atoms in a 1-g sample of aspirin
(C9H8O4).
5. …illustrates the schematic diagram of a
combustion device used to analyze organic
compounds. Explain how the data relating to
the mass of CO2 produced and the mass of
H2O produced can be manipulated to
determine the empirical formula.
A compound contains only C,H, and O.
Combustion of 10.68 mg of the compound
yields 16.01 mg CO2 and 4.37 mg H2O.
The molar mass of the compound is 176.1
g/mol. What are the empirical and molecular
formulas of the compound?
• A 0.755-g sample of hydrated copper(II)
sulfate CuSO4 xH2O was heated carefully until
it had changed completely to anhydrous
copper(II) sulfate with a mass of 0.483g.
Determine the value of x, also called number
of water of hydration. It specifies the number
of water molecules per formula unit of CuSO4
in the hydrated crystal.
Reaction Stoichiometry
4. Give the balanced equation:
6. Consider the hypothetical reaction between A2 and AB
pictured below:
• What is the balanced equation?
• If 2.5 mol A2 is reacted with excess AB, how many moles of
product will form?
• If the mass of AB is 30 amu and the mass of A2 is 40 amu,
what is the mass of the product?
• If 15g of AB is reacted, what mass of A2 is required to react
with all of the AB, and what mass of product is formed?
7. Consider the following mixture of SO2 and O2:
• If SO2 and O2 react to form SO3, draw a
representation of the product mixture
assuming the reaction goes to completion.
What is the limiting reactant in the reaction?
• If 96g of SO2 reacts with 32g O2, what mass of
product will form?
8. In an experiment, varying masses of sodium
metal are reacted with a fixed initial mass of
chlorine gas. The results of the experiment are
shown by the graph below:
Explain the general shape of
the graph and estimate the
amount of chlorine gas used
in this experiment.
9. A sample of limestone, calcium carbonate,
and other soil materials was heated, and the
limestone decomposed to give calcium oxide
and carbon dioxide:
A 1.506g sample of limestone-containing
material gave 0.558g of CO2 in addition to
CaO, after being heated at a high
temperature. What is the mass percent of
CaCO3 in the original sample?
This statue of George Washington was first put
outside in New York City in 1944.
During the next 58 years, acid rain caused
significant damage to the statue.