Chemical Reactions
Pre-Test
Name:
Date:
1. The chart below shows the amount of gas that is produced when two reactants (a solid and a liquid)
are combined. However, one of the boxes is missing information. Which is most likely the missing
value?
Reactant A (g)
2
3.3
1
Reactant B (ml)
20
33
10
Product (ml)
250
150
A. 29
B. 172
C. 246
D. 413
2. When zinc (Zn) is added to hydrochloric acid (HCl), hydrogen gas (H2) is produced. The graph
below shows the volume of hydrogen gas produced when different quantities of hydrochloric acid
are added to 5g of zinc. Explain why the graph’s line flattens out at a certain point.
1200
1000
Volume H2 gas
(ml)
800
600
400
200
0
0
20
40
60
80
100
120
Volume of HCl (ml)
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Cognitive Learning Systems, Inc.
© 2015
1
LabLearner™
Pre-Test
Chemical Reactions
3. Peter is timing the rate of reaction between two substances when they are combined. The amount of
each reactant that will be used for each trial is shown in the table below. Which trial will likely have
the fastest rate of reaction?
Trial
Reactant A
Reactant B
1
2
3
2g
2g
2g
10ml
20ml
30ml
A. Trial 1
B. Trial 2
C. Trial 3
D. The reaction rate will be the same for all Trials.
4. True or False
An increase in temperature is an indication that a chemical reaction is occurring between two
reactants.
5. Which of the following is most likely NOT a chemical reaction?
A. NaCl + H2O → H2O + NaCl
B. Two substances combine and produce hydrogen gas.
C. Two reactants combine to form two products.
D. All of the above.
Cognitive Learning Systems, Inc.
© 2015
2
LabLearner™
Pre-Test
Chemical Reactions
6. Considering the types and numbers of reactants and products, which of the following is a valid
equation for a chemical reaction?
A.
Na
+
Sodium
Cl
→
Chlorine
NaCl
Sodium Chloride
+
2H2O
Water
B.
2Ag
+
Silver
S
→
Sulfur
Ag2S
Silver Sulfide
C.
H2
+
Hydrogen
S
Sulfur
→
H2 O
Water
D. All of the above
7. Adam combined vinegar and baking soda inside the flask and balloon below. During the reaction,
the baking soda was used up. Also, gas was created and trapped inside the balloon. Before the
reaction, the flask and the reactants had a mass of 300 g. What statement could be made about the
total mass of the flask’s contents after the reaction?
A. The mass is greater than 300g.
B. The mass is less than 300 g.
C. The mass equals 300g.
D. The mass cannot be determined.
Cognitive Learning Systems, Inc.
© 2015
3
LabLearner™
Pre-Test
Chemical Reactions
8. True or False
The amount of product that can be produced is determined by the rate of reaction.
9. Four students are combining reactants to produce chemical reactions. The amount of each reactant
and the catalyst that the students used are shown in the table below. All four reactions are presented
in the table below. Based on the information in the table, which reaction graphed probably shows
Mary’s results.
Student
Name
Bill
Mary
Jen
Sam
Reactant A
(g)
10
100
50
20
Reactant B
(ml)
10
0
50
50
Catalyst
(ml)
2
100
10
10
A. Reaction 1
B. Reaction 2
C. Reaction 3
D. Reaction 4
10. Keith is combining two reactants in order to create a chemical reaction. If he adds a catalyst to the
reactants as well, what can he expect to happen?
A. The rate of reaction will change.
B. The amount of product will increase.
C. The amount of product will decrease.
D. The catalyst will have no effect on the reaction.
Cognitive Learning Systems, Inc.
© 2015
4
LabLearner™
Pre-Test
Chemical Reactions
11. Look at the chemical reaction below. Which of the following is a product of the reaction?
CH4
+
2O2
Methane Gas
Oxygen
→
CO2
+
Carbon Dioxide
2H2O
+
Heat
Water
A. Heat
B. CH4
C. CO2
D. A and C
12. True or False
Sometimes a product can look unchanged even though a chemical reaction has taken place.
13. Ben, Dave and Mary are each combining two solutions: hydrochloric acid (HCl) and sodium
hydroxide (NaOH). The equation for this chemical reaction is shown below. The chart shows the
volumes and concentrations that the students used when preparing their reactions. Should each
student get the same amount of product when the reactions are complete? Explain your answer.
HCl
+
Hydrochloric Acid
NaOH
→
Sodium Hydroxide
Student
Ben
Dave
Mary
Concentration of
HCl and NaOH
(g/100 ml)
5.4
10.8
16.2
NaCl
Sodium Chloride
+
H2 O
Water
Volume of
HCl and NaOH
(ml)
30
30
30
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Cognitive Learning Systems, Inc.
© 2015
5
Chemical Reactions
Pre-Test Key
Name:
Date:
1. The chart below shows the amount of gas that is produced when two reactants (a solid and a liquid)
are combined. However, one of the boxes is missing information. Which is most likely the missing
value?
Reactant A (g)
2
3.3
1
Reactant B (ml)
20
33
10
Product (ml)
250
150
A. 29
B. 172
C. 246
D. 413
2. When zinc (Zn) is added to hydrochloric acid (HCl), hydrogen gas (H2) is produced. The graph
below shows the volume of hydrogen gas produced when different quantities of hydrochloric acid
are added to 5g of zinc. Explain why the graph’s line flattens out at a certain point.
1200
1000
Volume H2 gas
(ml)
800
600
400
200
0
0
20
40
60
80
100
120
Volume of HCl (ml)
Student answers may vary. In order for a reaction to take place, both products must be present in
the reaction. Once one reactant is used up, the reaction can no longer take place. The flat line on
the graph indicates that 50 ml of hydrochloric acid causes all of the zinc to completely react.
Adding more hydrochloric acid will not increase the volume of gas produced because there won’t
be enough zinc to react to the extra acid
Cognitive Learning Systems, Inc.
© 2015
1
LabLearner™
Pre-Test Key
Chemical Reactions
3. Peter is timing the rate of reaction between two substances when they are combined. The amount of
each reactant that will be used for each trial is shown in the table below. Which trial will likely have
the fastest rate of reaction?
Trial
Reactant A
Reactant B
1
2
3
2g
2g
2g
10ml
20ml
30ml
A. Trial 1
B. Trial 2
C. Trial 3
D. The reaction rate will be the same for all Trials.
4. True or False
An increase in temperature is an indication that a chemical reaction is occurring between two
reactants.
5. Which of the following is most likely NOT a chemical reaction?
A. NaCl + H2O → H2O + NaCl
B. Two substances combine and produce hydrogen gas.
C. Two reactants combine to form two products.
D. All of the above.
Cognitive Learning Systems, Inc.
© 2015
2
LabLearner™
Pre-Test Key
Chemical Reactions
6. Considering the types and numbers of reactants and products, which of the following is a valid
equation for a chemical reaction?
A.
Na
+
Sodium
Cl
→
Chlorine
NaCl
Sodium Chloride
+
2H2O
Water
B.
2Ag
+
Silver
S
→
Sulfur
Ag2S
Silver Sulfide
C.
H2
+
Hydrogen
S
Sulfur
→
H2 O
Water
D. All of the above
7. Adam combined vinegar and baking soda inside the flask and balloon below. During the reaction,
the baking soda was used up. Also, gas was created and trapped inside the balloon. Before the
reaction, the flask and the reactants had a mass of 300 g. What statement could be made about the
total mass of the flask’s contents after the reaction?
A. The mass is greater than 300g.
B. The mass is less than 300 g.
C. The mass equals 300g.
D. The mass cannot be determined.
Cognitive Learning Systems, Inc.
© 2015
3
LabLearner™
Pre-Test Key
Chemical Reactions
8. True or False
The amount of product that can be produced is determined by the rate of reaction.
9. Four students are combining reactants to produce chemical reactions. The amount of each reactant
and the catalyst that the students used are shown in the table below. All four reactions are presented
in the table below. Based on the information in the table, which reaction graphed probably shows
Mary’s results.
Student
Name
Bill
Mary
Jen
Sam
Reactant A
(g)
10
100
50
20
Reactant B
(ml)
10
0
50
50
Catalyst
(ml)
2
100
10
10
A. Reaction 1
B. Reaction 2
C. Reaction 3
D. Reaction 4
10. Keith is combining two reactants in order to create a chemical reaction. If he adds a catalyst to the
reactants as well, what can he expect to happen?
A. The rate of reaction will change.
B. The amount of product will increase.
C. The amount of product will decrease.
D. The catalyst will have no effect on the reaction.
Cognitive Learning Systems, Inc.
© 2015
4
LabLearner™
Pre-Test Key
Chemical Reactions
11. Look at the chemical reaction below. Which of the following is a product of the reaction?
CH4
+
2O2
Methane Gas
Oxygen
→
CO2
+
Carbon Dioxide
2H2O
+
Heat
Water
A. Heat
B. CH4
C. CO2
D. A and C
12. True or False
Sometimes a product can look unchanged even though a chemical reaction has taken place.
13. Ben, Dave and Mary are each combining two solutions: hydrochloric acid (HCl) and sodium
hydroxide (NaOH). The equation for this chemical reaction is shown below. The chart shows the
volumes and concentrations that the students used when preparing their reactions. Should each
student get the same amount of product when the reactions are complete? Explain your answer.
HCl
+
Hydrochloric Acid
NaOH
→
Sodium Hydroxide
Student
Ben
Dave
Mary
Concentration of
HCl and NaOH
(g/100 ml)
5.4
10.8
16.2
NaCl
Sodium Chloride
+
H2 O
Water
Volume of
HCl and NaOH
(ml)
30
30
30
Student answers may vary. The amount of reactants increases when their concentrations
increase but their volumes stay the same. Therefore, even though each student is using the same
volume of reactants, they are using different amounts of reactants because the concentrations are
different. Ben’s reaction will produce the least amount of product while Mary’s reaction will
produce the most product.
Cognitive Learning Systems, Inc.
© 2015
5
Chemical Reactions
Post-Test
Name:
Date:
1. Ben, Dave and Mary are each combining two solutions: hydrochloric acid (HCl) and sodium
hydroxide (NaOH). The equation for this chemical reaction is shown below. The chart shows the
volumes and concentrations that the students used when preparing their reactions. Should each
student get the same amount of product when the reactions are complete? Explain your answer.
HCl
+
Hydrochloric Acid
NaOH
→
Sodium Hydroxide
Student
Ben
Dave
Mary
Concentration of
HCl and NaOH
(g/100 ml)
5.4
10.8
16.2
NaCl
Sodium Chloride
+
H2 O
Water
Volume of
HCl and NaOH
(ml)
30
30
30
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
2. The chart below shows the amount of gas that is produced when two reactants (a solid and a liquid)
are combined. However, one of the boxes is missing information. Which is most likely the missing
value?
Reactant A (g)
2
3.3
1
Reactant B (ml)
20
33
10
Product (ml)
250
150
A. 29
B. 172
C. 246
D. 413
Cognitive Learning Systems, Inc.
© 2015
1
LabLearner™
Post-Test
Chemical Reactions
3. Keith is combining two reactants in order to create a chemical reaction. If he adds a catalyst to the
reactants as well, what can he expect to happen?
A. The rate of reaction will change.
B. The amount of product will increase.
C. The amount of product will decrease.
D. The catalyst will have no effect on the reaction.
4. True or False
Sometimes a product can look unchanged even though a chemical reaction has taken place.
5. True or False
An increase in temperature is an indication that a chemical reaction is occurring between two
reactants.
6. Considering the types and numbers of reactants and products, which of the following is a valid
equation for a chemical reaction?
A.
Na
+
Sodium
Cl
→
Chlorine
NaCl
Sodium Chloride
+
2H2O
Water
B.
2Ag
+
Silver
S
→
Sulfur
Ag2S
Silver Sulfide
C.
H2
Hydrogen
+
S
Sulfur
→
H2 O
Water
D. All of the above
Cognitive Learning Systems, Inc.
© 2015
2
LabLearner™
Post-Test
Chemical Reactions
7. Peter is timing the rate of reaction between two substances when they are combined. The amount of
each reactant that will be used for each trial is shown in the table below. Which trial will likely have
the fastest rate of reaction?
Trial
Reactant A
Reactant B
1
2
3
2g
2g
2g
10ml
20ml
30ml
A. Trial 1
B. Trial 2
C. Trial 3
D. The reaction rate will be the same for all Trials.
8. Adam combined vinegar and baking soda inside the flask and balloon below. During the reaction,
the baking soda was used up. Also, gas was created and trapped inside the balloon. Before the
reaction, the flask and the reactants had a mass of 300 g. What statement could be made about the
total mass of the flask’s contents after the reaction?
A. The mass is greater than 300g.
B. The mass is less than 300 g.
C. The mass equals 300g.
D. The mass cannot be determined.
Cognitive Learning Systems, Inc.
© 2015
3
LabLearner™
Post-Test
Chemical Reactions
9. True or False
The amount of product that can be produced is determined by the rate of reaction.
10. Four students are combining reactants to produce chemical reactions. The amount of each reactant
and the catalyst that the students used are shown in the table below. All four reactions are presented
in the table below. Based on the information in the table, which reaction graphed probably shows
Mary’s results.
Student
Name
Bill
Mary
Jen
Sam
Reactant A
(g)
10
100
50
20
Reactant B
(ml)
10
0
50
50
Catalyst
(ml)
2
100
10
10
A. Reaction 1
B. Reaction 2
C. Reaction 3
D. Reaction 4
11. Which of the following is most likely NOT a chemical reaction?
A. NaCl + H2O → H2O + NaCl
B. Two substances combine and produce hydrogen gas.
C. Two reactants combine to form two products.
D. All of the above.
Cognitive Learning Systems, Inc.
© 2015
4
LabLearner™
Post-Test
Chemical Reactions
12. When zinc (Zn) is added to hydrochloric acid (HCl), hydrogen gas (H2) is produced. The graph
below shows the volume of hydrogen gas produced when different quantities of hydrochloric acid
are added to 5g of zinc. Explain why the graph’s line flattens out at a certain point.
1200
1000
Volume H2 gas
(ml)
800
600
400
200
0
0
20
40
60
80
100
120
Volume of HCl (ml)
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
13. Look at the chemical reaction below. Which of the following is a product of the reaction?
CH4
Methane Gas
+
2O2
Oxygen
→
CO2
Carbon Dioxide
+
2H2O
+
Heat
Water
A. Heat
B. CH4
C. CO2
D. A and C
Cognitive Learning Systems, Inc.
© 2015
5
Chemical Reactions
Post-Test Key
Name:
Date:
1. Ben, Dave and Mary are each combining two solutions: hydrochloric acid (HCl) and sodium
hydroxide (NaOH). The equation for this chemical reaction is shown below. The chart shows the
volumes and concentrations that the students used when preparing their reactions. Should each
student get the same amount of product when the reactions are complete? Explain your answer.
HCl
+
Hydrochloric Acid
NaOH
→
Sodium Hydroxide
Student
Ben
Dave
Mary
Concentration of
HCl and NaOH
(g/100 ml)
5.4
10.8
16.2
NaCl
Sodium Chloride
+
H2 O
Water
Volume of
HCl and NaOH
(ml)
30
30
30
Student answers may vary. The amount of reactants increases when their concentrations
increase but their volumes stay the same. Therefore, even though each student is using the same
volume of reactants, they are using different amounts of reactants because the concentrations are
different. Ben’s reaction will produce the least amount of product while Mary’s reaction will
produce the most product.
2. The chart below shows the amount of gas that is produced when two reactants (a solid and a liquid)
are combined. However, one of the boxes is missing information. Which is most likely the missing
value?
Reactant A (g)
2
3.3
1
Reactant B (ml)
20
33
10
Product (ml)
250
150
A. 29
B. 172
C. 246
D. 413
Cognitive Learning Systems, Inc.
© 2015
1
LabLearner™
Post-Test Key
Chemical Reactions
3. Keith is combining two reactants in order to create a chemical reaction. If he adds a catalyst to the
reactants as well, what can he expect to happen?
A. The rate of reaction will change.
B. The amount of product will increase.
C. The amount of product will decrease.
D. The catalyst will have no effect on the reaction.
4. True or False
Sometimes a product can look unchanged even though a chemical reaction has taken place.
5. True or False
An increase in temperature is an indication that a chemical reaction is occurring between two
reactants.
6. Considering the types and numbers of reactants and products, which of the following is a valid
equation for a chemical reaction?
A.
Na
+
Sodium
Cl
→
Chlorine
NaCl
Sodium Chloride
+
2H2O
Water
B.
2Ag
+
Silver
S
→
Sulfur
Ag2S
Silver Sulfide
C.
H2
Hydrogen
+
S
Sulfur
→
H2 O
Water
D. All of the above
Cognitive Learning Systems, Inc.
© 2015
2
LabLearner™
Post-Test Key
Chemical Reactions
7. Peter is timing the rate of reaction between two substances when they are combined. The amount of
each reactant that will be used for each trial is shown in the table below. Which trial will likely have
the fastest rate of reaction?
Trial
Reactant A
Reactant B
1
2
3
2g
2g
2g
10ml
20ml
30ml
A. Trial 1
B. Trial 2
C. Trial 3
D. The reaction rate will be the same for all Trials.
8. Adam combined vinegar and baking soda inside the flask and balloon below. During the reaction,
the baking soda was used up. Also, gas was created and trapped inside the balloon. Before the
reaction, the flask and the reactants had a mass of 300 g. What statement could be made about the
total mass of the flask’s contents after the reaction?
A. The mass is greater than 300g.
B. The mass is less than 300 g.
C. The mass equals 300g.
D. The mass cannot be determined.
Cognitive Learning Systems, Inc.
© 2015
3
LabLearner™
Post-Test Key
Chemical Reactions
9. True or False
The amount of product that can be produced is determined by the rate of reaction.
10. Four students are combining reactants to produce chemical reactions. The amount of each reactant
and the catalyst that the students used are shown in the table below. All four reactions are presented
in the table below. Based on the information in the table, which reaction graphed probably shows
Mary’s results.
Student
Name
Bill
Mary
Jen
Sam
Reactant A
(g)
10
100
50
20
Reactant B
(ml)
10
0
50
50
Catalyst
(ml)
2
100
10
10
A. Reaction 1
B. Reaction 2
C. Reaction 3
D. Reaction 4
11. Which of the following is most likely NOT a chemical reaction?
A. NaCl + H2O → H2O + NaCl
B. Two substances combine and produce hydrogen gas.
C. Two reactants combine to form two products.
D. All of the above.
Cognitive Learning Systems, Inc.
© 2015
4
LabLearner™
Post-Test Key
Chemical Reactions
12. When zinc (Zn) is added to hydrochloric acid (HCl), hydrogen gas (H2) is produced. The graph
below shows the volume of hydrogen gas produced when different quantities of hydrochloric acid
are added to 5g of zinc. Explain why the graph’s line flattens out at a certain point.
1200
1000
Volume H2 gas
(ml)
800
600
400
200
0
0
20
40
60
80
100
120
Volume of HCl (ml)
Student answers may vary. In order for a reaction to take place, both products must be present in
the reaction. Once one reactant is used up, the reaction can no longer take place. The flat line on
the graph indicates that 50 ml of hydrochloric acid causes all of the zinc to completely react.
Adding more hydrochloric acid will not increase the volume of gas produced because there won’t
be enough zinc to react to the extra acid
13. Look at the chemical reaction below. Which of the following is a product of the reaction?
CH4
Methane Gas
+
2O2
Oxygen
→
CO2
Carbon Dioxide
+
2H2O
+
Heat
Water
A. Heat
B. CH4
C. CO2
D. A and C
Cognitive Learning Systems, Inc.
© 2015
5