1. Stoichiometry: Calculations with Chemical Formulas and Equations
Chemistry, The Central Science, 11th edition Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, and Catherine J. Murphy
Chapter 3
Stoichiometry: Calculations with Chemical Formulas and Equations
Dana & Michelle Chatellier
University of Delaware
© Copyright 2009, Pearson Education

2. yields. reactants. products. coefficients.
In a chemical equation, the substances to the left of the arrow are called the:
yields.
reactants.
products.
coefficients.

3. yields. reactants. products. coefficients.
In a chemical equation, the substances to the left of the arrow are called the:
yields.
reactants.
products.
coefficients.

4. When hydrocarbons are burned in air, they form:
water and carbon dioxide.
charcoal.
methane.
oxygen and water.

5. When hydrocarbons are burned in air, they form:
water and carbon dioxide.
charcoal.
methane.
oxygen and water.

6. The formula weight of Na3PO4 is:
70 grams/mole
164 grams/mole
265 grams/mole
116 grams/mole

7. The formula weight of Na3PO4 is:
70 grams/mole
164 grams/mole
265 grams/mole
116 grams/mole

8. The percentage by mass of phosphorus in Na3PO4 is:
44.0%
11.7%
26.7%
18.9%

9. The percentage by mass of phosphorus in Na3PO4 is:
44.0%
11.7%
26.7%
18.9%

10. The formula weight of any substance is equal to:
Avogadro’s number.
its atomic weight.
its density.
its molar mass.

11. The formula weight of any substance is equal to:
Avogadro’s number.
its atomic weight.
its density.
its molar mass.

12. Ethyl alcohol contains 52. 2% C, 13. 0% H, and 34. 8 % O by mass
Ethyl alcohol contains 52.2% C, 13.0% H, and 34.8 % O by mass. What is the empirical formula of ethyl alcohol?
a. C2H5O2
C2H6O
C2H6O2
C3H4O2

13. Ethyl alcohol contains 52. 2% C, 13. 0% H, and 34. 8 % O by mass
Ethyl alcohol contains 52.2% C, 13.0% H, and 34.8 % O by mass. What is the empirical formula of ethyl alcohol?
a. C2H5O2
C2H6O
C2H6O2
C3H4O2

14. Methyl methacrylate has a molar mass of 100 g/mole
Methyl methacrylate has a molar mass of 100 g/mole. When a sample of methyl methacrylate weighing 3.14 mg was completely combusted, the only products formed were 6.91 mg of CO2 and 2.26 mg of water. What is methyl methacrylate’s molecular formula?
a. C7H b. C6H12O
c. C5H8O d. C4H4O3

15. Methyl methacrylate has a molar mass of 100 g/mole
Methyl methacrylate has a molar mass of 100 g/mole. When a sample of methyl methacrylate weighing 3.14 mg was completely combusted, the only products formed were 6.91 mg of CO2 and 2.26 mg of water. What is methyl methacrylate’s molecular formula?
a. C7H b. C6H12O
c. C5H8O d. C4H4O3

16. 2 Fe + 3 Cl2  2 FeCl3 If 10. 0 grams of iron and 20
2 Fe Cl2  2 FeCl3 If 10.0 grams of iron and 20.0 grams of chlorine react as shown, what is the theoretical yield of ferric chloride?
10.0 grams
20.0 grams
29.0 grams
30.0 grams

17. 2 Fe + 3 Cl2  2 FeCl3 If 10. 0 grams of iron and 20
2 Fe Cl2  2 FeCl3 If 10.0 grams of iron and 20.0 grams of chlorine react as shown, what is the theoretical yield of ferric chloride?
10.0 grams
20.0 grams
29.0 grams
30.0 grams

18. C3H4O C2H6O  C7H12O H2O When 15.0 grams of each reactant were mixed together, the yield of C7H12O4 was 15.0 grams. What was the percentage yield?
100.0%
75.0%
65.0%
50.0%

19. C3H4O C2H6O  C7H12O H2O When 15.0 grams of each reactant were mixed together, the yield of C7H12O4 was 15.0 grams. What was the percentage yield?
100.0%
75.0%
65.0%
50.0%

20. The percentage yield of a reaction is (100. 0%)(X)
The percentage yield of a reaction is (100.0%)(X). Which of the following is X?
theoretical yield / actual yield
calculated yield / actual yield
calculated yield / theoretical yield
actual yield / theoretical yield

21. The percentage yield of a reaction is (100. 0%)(X)
The percentage yield of a reaction is (100.0%)(X). Which of the following is X?
theoretical yield / actual yield
calculated yield / actual yield
calculated yield / theoretical yield
actual yield / theoretical yield