AP Chemistry Test (Chapter 3)
(Autumn)
Multiple Choice and FIB (45%)
1)
Which of these lab errors would cause a low % yield O2 ?
∆
2 KClO3 (s)  2 KCl (s) + 3 O2 (g)
I)
II)
III)
IV)
A)
C)
E)
2)
Using a crucible that has soot stuck to it
Using a low mass of KClO3
Heating the crucible an insufficient length of time
Spilling some of the KCl
I and III
II and IV
None of these
B)
D)
III and IV
III
What coefficients balance this reaction?
Fe3P4 + K2SO4  Fe(SO4)2 + K3P
A)
C)
E)
1, 1, 3, 4
3, 2, 3, 2
None of these
B)
D)
3)
What is the name of NH4BrO4 ● 4 H2O?
4)
Which one is an empirical formula?
A)
C)
E)
C13H26
C12H21O6
C10H20O3
1, 6, 3, 4
2, 3, 3, 2
B)
D)
P4O10
N2O6
Please use the following information to answer questions 5-8.
5.48 mol A4 reacts with 4.22 mol B7 in this reaction in a sealed flask: 35 A4 + 12 B7  28 A5B3
5)
Which one is the limiting reagent?
6)
How many mol A5B3 are produced?
7)
How many mol of the excess reagent are consumed during the reaction?
8)
How many total mol are in the flask at the end of the reaction?
9)
Please consider these two samples.
Sample #1 is a mixture of iron and sulfur in a mole ratio of 1:1.
Sample #2 is FeS.
Please choose all true statements about these samples.
I)
II)
III)
IV)
V)
A)
C)
E)
Both samples are chemically combined.
Sample #1 would show magnetic properties and sample #2 would not.
Sample #1 would smell differently than sample #2.
Both samples would have similar physical and chemical properties.
Sample #1 is composed of atoms while sample #2 is composed of molecules.
I, II, III, IV, V
II, III, V
None of these
B)
D)
II, III, IV, V
II, III
10)
29.0 g NaCl is dissolved in 60.0 g H2O. What is the % NaCl in the solution by mass?
11)
What is the formula for chromium (III) sulfite heptahydrate?
Please consider this container to answer questions 12-14.
Hydrogen reacts with oxygen to form H2O.
O
O
H
O
H
H
H
H
O
H
H
O
H
H
H
O
H
H
H
O
H
O
O
O
O
O
H
Reactants
12)
How many molecules of limiting reagent are consumed in this reaction?
13)
How many molecules of water are produced?
14)
How many molecules are in the flask at the end of the reaction?
15)
Which one is the smallest quantity?
A)
C)
E)
1 X 1012 Tm
1 X 1015 fm
1 X 10 –9 nm
B)
D)
H
H
O
H
H
O
O
H
1 X 10 –6 Mm
1 X 1012 pm
O
Problems (60%)
1)
Please show all your work for any credit.
The following lab results were obtained when copper was strongly heated in the presence of
excess oxygen. What is the empirical formula of the metallic oxide? Assume the copper did
not react with atmospheric N2.
Mass of empty crucible & cover
Mass of crucible, cover & copper (before combustion)
Mass of crucible, cover & copper (after combustion)
50.0000 g
52.0000 g
52.4197 g
2)
A 10.000-g sample of an organic compound composed entirely of carbon, hydrogen &
oxygen was burned to produce 12.5647 g CO2 and 4.2872 g H2O. Assume complete
combustion The molar mass of the compound is 735.56 g. What is the molecular formula of
this hydrocarbon?
3)
A phosphoric acid solution is 2.91% by mass.
The density of the phosphoric acid solution is 1.11 g/ml.
How many acetate ions will react with 70.82 mL of the phosphoric acid solution?
3 Fe (C2H3O2)5 + 5 H3PO4  15 HC2H3O2 + Fe3(PO4)5
4)
A reaction mixture contains 7.51 L C6H14 and 42.1 L O2. What mass of excess reagent
remains after the reaction has gone to completion?
2 C6H14 + 19 O2  12 CO2 + 14 H2O
5)
A student uses 26.4 g of 11.0% HCl solution to neutralize 12.7 g Al2(CO3)3. The student
then collects and dries 3.09 g AlCl3. What is the % yield?
6 HCl + Al2(CO3)3  2 AlCl3 + 3 H2O + 3 CO2
6)
An ore (rock) contains 28.9 % emerald, Be3Al2(SiO3)6 by mass. What mass of rock would
produce 4.11 X 1024 atoms of Si?
AP Chemistry Test (Chapter 3)
(Winter)
Multiple Choice and FIB (45%)
1)
Which of these lab errors would cause a low % yield O2 ?
∆
2 KClO3 (s)  2 KCl (s) + 3 O2 (g)
I)
II)
III)
IV)
A)
C)
E)
2)
Using a crucible that has soot stuck to it
Using a low mass of KClO3
Heating the crucible an insufficient length of time
Spilling some of the KCl
II and IV
I and III
None of these
B)
D)
III
III and IV
What coefficients balance this reaction?
Fe3P4 + K2SO4  Fe(SO4)2 + K3P
A)
C)
E)
1, 1, 3, 4
3, 2, 3, 2
None of these
B)
D)
3)
What is the name of NH4BrO ● 6 H2O?
4)
Which one is an empirical formula?
A)
C)
E)
C13H26
C12H21O6
C10H20O3
1, 6, 3, 4
2, 3, 3, 2
B)
D)
P4O10
N2O6
Please use the following information to answer questions 5-8.
8.21 mol A4 reacts with 7.95 mol B7 in this reaction in a sealed flask: 35 A4 + 12 B7  28 A5B3
5)
Which one is the limiting reagent?
6)
How many mol A5B3 are produced?
7)
How many mol of the excess reagent are consumed during the reaction?
8)
How many total mol are in the flask at the end of the reaction?
9)
Please consider these two samples.
Sample #1 is a mixture of iron and sulfur in a mole ratio of 1:1.
Sample #2 is FeS.
Please choose all true statements about these samples.
I)
II)
III)
IV)
V)
A)
C)
E)
Both samples are chemically combined.
Sample #1 would show magnetic properties and sample #2 would not.
Sample #1 would smell differently than sample #2.
Both samples would have similar physical and chemical properties.
Sample #1 is composed of atoms while sample #2 is composed of molecules.
II, III, IV, V
II, III
None of these
B)
D)
I, II, III, IV, V
II, III, V
10)
19.0 g NaCl is dissolved in 70.0 g H2O. What is the % NaCl in the solution by mass?
11)
What is the formula for chromium (II) phosphite tetrahydrate?
Please consider this container to answer questions 12-14.
Hydrogen reacts with oxygen to form H2O.
O
O
H
O
H
H
H
H
O
O
H
O
H
O
O
O
O
H
How many molecules of limiting reagent are consumed in this reaction?
13)
How many molecules of water are produced?
14)
How many molecules are in the flask at the end of the reaction?
15)
Which one is the smallest quantity?
B)
D)
H
H
12)
1 X 1012 Tm
1 X 10 –9 nm
1 X 10 15 fm
O
H
Reactants
A)
C)
E)
O
H
H
H
H
H
H
H
H
H
O
H
H
O
O
H
1 X 10 –6 Mm
1 X 1012 pm
O
H
Problems (60%)
1)
Please show all your work for any credit.
The following lab results were obtained when copper was strongly heated in the presence of
excess oxygen. What is the empirical formula of the metallic oxide? Assume the copper did
not react with atmospheric N2.
Mass of empty crucible & cover
Mass of crucible, cover & copper (before combustion)
Mass of crucible, cover & copper (after combustion)
50.0000 g
52.0000 g
52.4197 g
2)
A 10.000-g sample of an organic compound composed entirely of carbon, hydrogen &
oxygen was burned to produce 12.5647 g CO2 and 4.2872 g H2O. Assume complete
combustion The molar mass of the compound is 735.56 g. What is the molecular formula of
this hydrocarbon?
3)
A phosphoric acid solution is 2.91% by mass.
The density of the phosphoric acid solution is 1.11 g/ml.
How many acetate ions will react with 70.82 mL of the phosphoric acid solution?
3 Fe (C2H3O2)5 + 5 H3PO4  15 HC2H3O2 + Fe3(PO4)5
4)
A reaction mixture contains 7.51 L C6H14 and 42.1 L O2. What mass of excess reagent
remains after the reaction has gone to completion?
2 C6H14 + 19 O2  12 CO2 + 14 H2O
5)
A student uses 26.4 g of 11.0% HCl solution to neutralize 12.7 g Al 2(CO3)3. The student
then collects and dries 3.09 g AlCl3. What is the % yield?
6 HCl + Al2(CO3)3  2 AlCl3 + 3 H2O + 3 CO2
6)
An ore (rock) contains 28.9 % emerald, Be3Al2(SiO3)6 by mass. What mass of rock would
produce 4.11 X 1024 atoms of Si?
AP Chemistry Test (Chapter 3)
Name______________________________
Form_____________________
Multiple Choice and FIB (45%)
1)
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11)
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2)
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12)
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3)
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13)
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4)
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14)
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5)
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15)
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6)
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7)
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8)
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9)
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10)
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Problems (60%)
Please show all your work for any credit.
1)
Please use only the front side of each piece of paper.
2)
Please number your problems clearly and consecutively.
3)
Please staple your problems to the back of this page in numerical order.
4)
Please write on the paper in the conventional manner.
5)
Please do not make a separate list of answers. Record your answer at the end of the work
supporting your answer.
6)
Please circle/box your answer at the end of the problem.