Chapter 9 Exam – Thursday, April 23
Name_________________________ Period____
Chapter 9 Review – Stoichiometry
Key Terms
1) Define the following terms:
a.
Stoichiometry
b. Actual yield
c.
Theoretical yield
d. Percent yield
e.
Limiting reactant
f.
Excess reactant
Mole Ratios
2) Balance the following chemical reaction then write the mole ratio for each of the following.
___NaHCO3 + ___H2SO4  ___CO2 + ___Na2SO4 + ___H2O
a.
Sulfuric acid to carbon dioxide
b. Sulfuric acid to water
c.
Sodium sulfate to sulfuric acid
d. Sodium sulfate to sodium bicarbonate
Stoichiometry
3) Balance the following reaction then answer the questions that follow.
___C8H18 + ____O2  ___CO2 + ___H2O
a.
How many moles of carbon dioxide are produced from 2.50 moles of oxygen?
b. How many grams of carbon dioxide are produced from 3.00 moles of C 8H18?
c.
How many moles of oxygen will react with 555 grams of C 8H18?
d. How many grams of water are produced when 2.50 grams of oxygen react with excess C 8H18?
4) Balance the following reaction then answer the questions that follow.
___Na + ___Cl2  ___NaCl
a.
How many moles of sodium are required to produce 5.5 moles of sodium chloride?
b. How many grams of chlorine are needed to produce 5.5 moles of sodium chloride?
c.
How many moles of sodium chloride are produced when 45.7 grams of chlorine react with excess
sodium?
d. How many grams of sodium are required to produce 56.77 grams of sodium chloride?
Percent Yield
5) Calculate the percent yield of iron III oxide when 245 grams was expected, but only 230 grams was
produced.
6) Balance the following chemical reaction then answer the questions that follow.
___Mg + ___HCl  ___H2 + ___MgCl2
a.
Calculate the theoretical yield of magnesium chloride if 125 grams of magnesium react with excess
hydrochloric acid.
b. Calculate the percent yield of magnesium chloride if 345 grams of magnesium chloride is recovered.
7) 505 grams of sodium is added to 505 grams of chlorine.
a.
Write the balanced chemical reaction.
b. Determine the theoretical amount of sodium chloride produced.
c.
Determine the amount of sodium chloride produced if the reaction is 92.4% efficient.
Limiting and Excess Reactants
8) 12.0 grams of sodium are added to 81.2 grams of water.
a.
Write the balanced chemical reaction.
b. How many grams of hydrogen are produced?
c. Identify the limiting AND excess reactants. Be specific.
9) 34.5 grams of sodium chloride reacts with 34.5 grams of bromine.
a. Write the balanced chemical reaction.
b. Using stoichiometry, determine the limiting reactant.
Helpful Hints and Equations:
Molar mass
Mole Ratio
Molar mass
Grams A --------> Moles A -------> Moles B ---------> Grams B
(Other helpful options: roadmap in notes 9-2, setup in notes 9-3)
Percent Yield = (Actual / Theoretical) x 100