75 Points
Chem I
Name_________________________ Period_______
Stoichiometry Problem Set #1
PART A. Answer questions (1-3) given the following equation:
Mg(s) + 2HCl (aq) → MgCl2(s) + H2(g)
1. How many grams of magnesium (Mg) is needed to produce 100. grams of
hydrogen (H2)?
1.____________
2. How many grams of hydrogen chloride (HCl) is needed to produce 200. g of
hydrogen (H2)?
2.____________
3. If 500. g of magnesium chloride (MgCl2) is produced in the above reaction, how
many grams of hydrogen (H2) would be produced?
3.____________
PART B. Answer questions (4-5) given the following equation:
P4(s) + 5O2 (g) → P4O10(g)
4. How many grams of tetraphosphorus decoxide (P4O10) is produced if you burn
50.0 grams of phosphorus with sufficient oxygen gas?
4.____________
5. How many grams of oxygen would be needed in problem 4?
5.____________
6. If 400. g of tetraphosphorus decoxide (P4O10) is needed for another experiment,
how much phosphorus would have to be burned?
6.____________
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Chem I
Stoichiometry Problem Set #2
Mass to Mass Relationships: Solve the following problems. If equations are provided, balance them first.
If equation are not provided, write reactants in formula form, including reaction conditions, and balance
the equation.
PART A
7. If excess ammonium sulfate reacts with 20.0 grams of calcium hydroxide, how many
grams of ammonia are produced?
(NH4)2SO4(aq) + Ca(OH)2(cr) → CaSO4(cr) + NH3(g) + H2O(l)
8. How many grams of sodium hydroxide are needed to completely neutralize 25.0 grams
of sulfuric acid?
NaOH (aq) + H2SO4(aq) → Na2SO4(cr) + H2O(l)
9. If 20.0 grams of zinc react with excess hydrochloric acid to produce zinc chloride
solution and hydrogen gas, how many grams of zinc chloride are produced?
1.____________
2.____________
3.____________
10. How many grams of chlorine gas must be reacted with excess sodium iodide solution to
produce 10.0 grams of sodium chloride and iodide gas?
4.____________
11. Solid potassium chlorate decomposes to form potassium chlroide and oxygen gas. How
many grams of oxygen are produced using 5.00 grams of solid potassium chlorate?
5.____________
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PART B
12. How many grams of copper are required to replace 4.00 grams of silver nitrate solution
which forms silver metal and copper (II) nitrate solution?
13. If excess sulfuric acid reacts with 30.0 grams of sodium chloride solution to form
sodium sulfate and hydrochloric acid, how many grams of hydrochloric acid are
produced?
14. How much aqueous silver phosphate is produced if 10.0 grams of silver acetate solution
is reacted with excess sodium phosphate solution to produce silver phosphate solid and
sodium acetate solution?
15. How many grams of magnesium oxide can be produced when 50.0 grams of magnesium
metal is combined with excess atmospheric oxygen in a synthesis reaction?
16. If propanol alcohol (C3H7OH) is combine with oxygen gas to form carbon dioxide gas
and water, how many grams of propanol alcohol are needed to produce 750 grams of
water?
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6.____________
7.____________
8.____________
9.____________
10.___________
Chem I
Stoichiometry Problem Set #3

Mass to Mass Relationships: Write formula equations with states of matter and rx condition, balance,
and perform requested conversion. Answer should be express in correct sig figs and units. Write
answer on line provided.
Part A
17. How much (grams) hydrogen gas in a test tube would be combined with 44 grams of
oxygen gas in the air to form water?
18. Solid lithium nitrate breaks down to form solid lithium nitrite and oxygen gas. How
many grams of lithium nitrite are formed from 350 grams of lithium nitrate?
19. Aluminum chlorate reacts with sulfuric acid to form aluminum sulfate solution and
chloric acid. How many grams of sulfuric acid are needed to form 100 grams of
aluminum sulfate?
1.____________
2.____________
3.____________
20. Chlorine gas and copper (I) iodide solution yield copper (I) chloride solution and iodine
gas. If 350 grams of iodine gas are formed, how many grams of copper (I) chloride are
also formed?
4.____________
21. Solid tin (IV) hydroxide and hydrochloric acid react to produce water and tin (IV)
chloride solution. If 450 grams of tin (IV) hydroxide are used, how many grams of
water can be produced?
5.____________
22. Ethanol alcohol (C2H5OH) in the presence of oxygen gas forms carbon dioxide gas and
water. How many grams of carbon dioxide has can be produced from 4.50 grams of
oxygen gas?
6.____________
23. Aluminum metal and lead (II) acetate solution forms aluminum acetate solution and lead
metal. Find the amount, in grams, of lead (II) acetate needed to form 125 grams of lead
metal.
7.____________
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Part B
24. Copper metal and silver carbonate soltuion form copper (II) carbonate solution and
silver metal. If you want to produce 400 grams of silver metal, how many grams of
silver carbonate are required?
25. Solid strontium chlorate decomposes into solid strontium chloride and oxygen gas when
heated. If you produce 210 grams of strontium chloride, how many grams of oxygen
gas are also produced?
8.____________
9.____________
26. Methane gas (CH4) combines to produce water and carbon dioxide gas. If you have 110
grams of methane gas, how many grams of oxygen gas are needed to use up the
methane?
10.___________
27. Crystalline magnesium carbonate, when heated, produced magnesium oxide and carbon
dioxide gas. If you produce 75.0 grams of magnesium oxide, how many grams of
magnesium carbonate were used?
11.___________
28. If 45.5 grams of sodium metal and exress chlorine gas combine to form crystalline
sodium chloride, how many grams of sodium chloride are produced?
12.___________
29. Solid diphosphorus pentoxide and solid barium oxide combine to form solid barium
phosphate. How many grams of barium phosphate are produced if 10.0 grams of
diphosphorus pentoxide are used?
13.___________
30. 50.0 grams of solid cadmiun hydroxide breaks down when heated to form solid
cadmium oxide and water. How many grams of cadmium oxide are formed?
14.___________
31. If the temperature reaches 25°C, solid iron reacts with water to form iron (III) oxide and
hydrogen gas. How much iron is needed to form 6.7 grams of hydrogen gas?
15.___________
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Chem I
Stoichiometry Problem Set #4
Part A

Limiting Reactants – If equations are provided, balance them and perform calculation. If there is not
an equation, write reactants and products in formula form, balance equation, and perform
calculation. Circle your answer!
32. For each of the following unbalanced equations, suppose 50.0 g of each reactant is
taken. Show by calculation which reactant is the limiting reactant.
a) MgCl2(aq) + O2(g) →
b) Al(s) +
Cl2(g)
→
Mg(ClO3)2(s)
AlCl3(s)
c) NaOH(s) + CO2(g) → Na2CO3(s) + H2O(l)
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Part B
33. Suppose that you have exactly 50.0 g of each reactant taken. Determine which is the
limiting and calculate what mass each product expected.
a) NH3(g) + Na(s) →
NaNH2(s) +
b) SO2(g) + NaOH(s) →
H2(g)
Na2SO3(s) +
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H2O(l)
34. For eachof the following unbalanced reactions, suppose exactly 150.00 g of each
reactant is taken. Determine which reactant is limiting, and determine the mass of each
product.
a) NaCl(s) + H2SO4(aq) →
HCl(aq) + Na2SO4(s)
b) C3H8(g) + O2(g) →
CO2(g) +
H2O(l)
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Part C
35. Lead (IV) chloride and sodium phosphate are mixed to form lead (IV) phosphate and
sodium chloride. An experiment uses 125.0 grams of lead (IV) chloride mixed with
100.0 grams of sodium phosphate. Determine which reactant is limiting and calculate
grams of each product produced.
36. Oxygen gas and zinc metal react to form zinc oxide ash. In an experiment, 75.0 grams
of oxygen combines with 100.0 grams of zinc. Determine which reactant is limiting and
calculate the grams of product produced.
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Chem I
Stoichiometry Problem Set #5

Excess Reactants – If equations are provided, balance them and perform calculation. If there is not
an equation, write reactants and products in formula form, balance equation, and perform
calculation. Circle your answer!
Part A. Excess Reactants
1. For each of the following unbalanced equations, suppose 10.0 g of each reactant is taken. Show by calculation
which reactant is the limiting reagent. Calculate the mass of excess reactant based on the limiting reactant.
a.
C2H6(g) + O2(g)  CO2(g)
+ H2O(l)
b. Ni(s) + Br2(g)  NiBr3(s)
c. KOH(s) + H2SO4(aq)  K2SO4(aq) + H2O(l)
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2. Suppose that you have exactly 50.0 g of ammonia gas (NH3) and 65.0 g of rubidium metal. Determine which is
the limiting reactant and the mass of the reactant that will be in excess.
a. NH3(g) + Rb(s)  RbNH2(s) + H2(g)
3. You take 125 grams of each reactant. Determine which reactant is limiting, and also determine what mass of the
two excess reactants will remain after the limiting reactant is consumed.
Li2B4O7(s) + H2CO3(aq) + H2O(l)  H3BO3(s)
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+ Li2CO3(aq)
Part B
4. An experiment uses 25.0 grams of lead(II) nitrate mixed with 45 grams of potassium iodide to produce a yellow
lead(II) iodide precipitate and clear potassium nitrate solution. Determine which reactant is limiting, calculate
grams of each product produced, and determine the mass remaining of the excess reactant.
5. In an experiment 55.0 grams of oxygen gas combines with 45.0 grams of magnesium metal to form magnesium
oxide ash. Determine which reactant is limiting, calculate grams of product produced, and determine the mass
remaining of the excess reactant.
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Chem I
Stoichiometry Problem Set #6

Percent Yield– If equations are provided, balance them and perform calculation. If there is not an
equation, write reactants and products in formula form, balance equation, and perform calculation.
Circle your answer!
Part A
Percent Yield
1. Find the %yield of an experiment if a student obtained 38.6 grams of carbon monoxide after reacting 75.5
grams of solid iron(III) oxide with excess carbon in the following unbalanced reaction:
Fe2O3(s) +
C(s)  Fe(s) + CO(g)
2. Find the %yield of an experiment if a student obtained 242 grams of aluminum oxide after reacting 135
grams of solid aluminum metal with excess sulfur monoxide gas in the following reaction:
Al(s) +
SO(g)  Al2O3(s) + S(s)
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3. Find the %yield of an experiment if a student obtained 231 grams of aspirin (C9H8O4) after reacting 200.
grams of C7H6O3 with excess C7H6O3 in the following reaction:
C7H6O3 + C4H6O3  C9H8O4 + C2H4O2
4. According to the following equation, calculate the percentage yield if 550.g of toluene is added to an excess
of nitric acid and provides 305 g of the p-nitrotoluene product.
C7H8 + HNO3  C7H7NO2 + H2O
Part B
5. Quicklime, CaO, can be prepared by roasting limestone, CaCO3, according to the chemical equation below.
When 200.g of CaCO3 are heated, the actual yield of CaO is 150.g. What is the percentage yield?
CaCO3  CaO + CO2
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6. Consider the following reaction unbalanced reaction:
CaCO3 + FePO4  Ca3(PO4)2 + Fe2(CO3)3
Assuming we start with 100. grams of calcium carbonate and 45.0 grams of iron (III) phosphate, calculate the
percent yield of calcium phosphate if 40.0 grams were collected in lab.

Step 1: Find the Limiting Reactant

Step 2: Calculate the Percent Yield
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