Name
Answer Key
Date
Chapter 9 – Stoichiometry – Chapter Review
Last page worked out for you.
Match each description on the right to the correct term on the left.
B
1. The substance that determines the amount of product that
can be formed in a reaction.
E
2. The amount of product that forms when a reaction is carried
out in the laboratory.
C. Theoretical yield
D
3. The calculation of quantities in chemical equations.
D. Stoichiometry
A
4. The ratio of the actual yield to the theoretical yield
expressed as a percent.
E.
Actual yield
F.
Excess reagent
F
5. The substance that is present in enough quantity to react
with a limiting reagent.
C
6. The maximum amount of products that could be formed
from given amounts of reactants.
A. Percent yield
B. Limiting reagent
Multiple Choice - Choose the best answer and write its letter in the blank.
D
7. How many moles of H2O would be required to produce 2.5 moles of O2?
2 H2O →
2 H2 +
O2
A. 2.0 mol
B. 2.5 mol
D
8. If 3.00 mol of CaCO3 undergo decomposition to form CaO and CO2, how many
grams of CO2 are produced?
CaCO3 →
CaO +
CO2
A. 3.00 g
B. 44.0 g
B
C. 4.0 mol
D. 5.0 mol
C. 88.0 g
D. 132 g
9. How many moles of H2O are produced when 240 grams of CuO react?
CuO +
H2
→
Cu
+
H2O
A. 1.0 mol
B. 3.0 mol
C. 18 mol
D. 54 mol
Name
C
Answer Key
2
10. If 1.0 mol of KmnO4 reacts with HCl, how many moles of H2O are produced?
16 HCl + 2 KMnO4 → 2 KCl + 2 MnCl2 + 5 Cl2 + 8 H2O
A. 0.50 mol
B. 2.0 mol
B
11. How many grams of KCl are produced when 1.0 mol of KmnO4 reacts?
16 HCl + 2 KMnO4 → 2 KCl + 2 MnCl2 + 5 Cl2 + 8 H2O
A. 1.0 g
B. 75 g
A
C. 4.0 mol
D. 8.0 mol
C. 150 g
D. 158 g
12. If 110 grams of HCl are used, how many moles of FeCl3 are produced?
6 HCl +
Fe2O3 →
2 FeCl3
+
3 H2O
A. 1.0 mol
B. 2.0 mol
C. 3.0 mol
D. 6.0 mol
C
13. How many grams of H2SO4 are required to produce 1.0 gram of H2?
Zn
+
H2SO4
→
ZnSO4
+
H2
A. 1.0 g
B. 2.0 g
C
14. If 18 grams of carbon react with oxygen to produce Carbon dioxide, how many
molecules of oxygen would be required?
→
CO2
C
+
O2
A. 1.5 molecules
B. 48 molecules
D
C. 49 g
D. 98 g
C. 9.0 X 1023 molecules
D. 3.2 X 1024 molecules
15. If 6.5 L of O2 react at STP, how many liters of NO2 are produced?
2 NO +
O2
→
2 NO2
A. 6.5 L
B. 3.2 L
C. 26 L
D. 13 L
Name
A
Answer Key
3
16. If 2.0 mol of Zn and 5.0 mol of HCl are allowed to react:
Zn
+
2 HCl →
ZnCl2 +
H2
2.0 mol
5.0 mol
2.0 mol Zn
2 mol HCl
= 4.0 mol HCl needed (They gave you 5.0 mol which is more than enough.)
1 mol Zn
A.
B.
C.
D.
B
Zn is the limiting reagent.
HCl is the limiting reagent.
1.0 mol of ZnCl2 is produced.
5.0 mol of H2 is produced.
17. In the above reaction (question #16), how many moles of excess reactant remain?
H2
Zn
+
2 HCl →
ZnCl2 +
If you only need 4.0 mol of HCl and they gave you 5.0 mol HCl, then,
5.0 mol HCl
- 4.0 mol HCl
1.0 mol HCl excess
A. 3.0 mol
B. 1.0 mol
C. 4.0 mol
D. 2.0 mol
actual yield
C
18. If 50.0 g of CaCO3 reacts to produce 20.0 g of CO2, what is the percent yield of
CO2?
CaCO3 →
CaO +
CO2
% Yield = Actual Yield
Theoretical Yield
A. 66.7 %
B. 40.0%
X 100
50.0 g
mol
xg
Theoretical Yield
C. 90.9%
D. 250 %
Theoretical Yield
C
mol
Actual Yield
19. A reaction that has been calculated to produce 60.0 g of CuCl2 actually produces
50.0 g of CuCl2. What is the percent yield?
% Yield = Actual Yield
Theoretical Yield
X 100
50.0 g X 100 = 83.3%
60.0 g
A. 0.833 %
B. 96.1 %
C. 83.3 %
D. 120 %
actual yield
D
20. If 12.7 grams of Cu reacting with Silver nitrate produced 38.1 grams of Silver, What
is the percent yield of silver in this reaction?
Cu
+
2 AgNO3
→
Cu(NO3)2
+
2Ag
12.7 g
mol
xg
mol
Theoretical Yield
A. 29.4 %
B. 56.7 %
% Yield = Actual Yield
Theoretical Yield
X 100
38.1 g X 100 = 88.8%
42.9 g
C. 77.3 %
D. 88.8%