Question 1

Which of the following materials is most likely to undergo oxidation?

Accepted Answer

A) Na 
B) Na+ 
C) Cl2 
D) Cl- 
E) both A and B 
A) Na 
B) Na+ 
C) Cl2 
D) Cl- 
E) both A and B

Question 2

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

Accepted Answer

A) Thick zinc walls prevent the battery from over heating. 
B) Thicker zinc walls prevent electrons from being lost into the surrounding environment. 
C) Thicker zinc walls last longer at holding in the battery acid. 
D) The zinc walls are transformed into zinc ions as the battery provides electricity. 
A) Thick zinc walls prevent the battery from over heating. 
B) Thicker zinc walls prevent electrons from being lost into the surrounding environment. 
C) Thicker zinc walls last longer at holding in the battery acid. 
D) The zinc walls are transformed into zinc ions as the battery provides electricity.

Question 3

What correlation might you expect between an element's ionization energy and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

Accepted Answer

A) An element with a high ionization energy tends to behave as a weak oxidizing agent and strong reducing agent. 
B) An element with a high ionization energy tends to behave as a strong oxidizing agent and strong reducing agent. 
C) An element with a high ionization energy tends to behave as a weak oxidizing agent and weak reducing agent. 
D) An element with a high ionization energy tends to behave as a strong oxidizing agent and weak reducing agent. 
A) An element with a high ionization energy tends to behave as a weak oxidizing agent and strong reducing agent. 
B) An element with a high ionization energy tends to behave as a strong oxidizing agent and strong reducing agent. 
C) An element with a high ionization energy tends to behave as a weak oxidizing agent and weak reducing agent. 
D) An element with a high ionization energy tends to behave as a strong oxidizing agent and weak reducing agent.

Question 4

What correlation might you expect between an element's electronegativity and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

Accepted Answer

A) Atoms with great electronegativity tend to behave as strong oxidizing agents and weak reducing agents. 
B) Atoms with great electronegativity tend to behave as weak oxidizing agents and weak reducing agents. 
C) Atoms with great electronegativity tend to behave as strong oxidizing agents and strong reducing agents. 
D) Atoms with great electronegativity tend to behave as weak oxidizing agents and strong reducing agents. 
A) Atoms with great electronegativity tend to behave as strong oxidizing agents and weak reducing agents. 
B) Atoms with great electronegativity tend to behave as weak oxidizing agents and weak reducing agents. 
C) Atoms with great electronegativity tend to behave as strong oxidizing agents and strong reducing agents. 
D) Atoms with great electronegativity tend to behave as weak oxidizing agents and strong reducing agents.

Question 5

Which of the following elements would be most useful for creating a p-type silicon?

Accepted Answer

A) As 
B) Sn 
C) Pb 
D) B 
E) Bi 
A) As 
B) Sn 
C) Pb 
D) B 
E) Bi

Question 6

The charge on the sulfur in the compound copper sulfide, Cu2S, is ________.

Accepted Answer

A) neutral 
B) -1 
C) -2 
D) +1 
E) +2 
A) neutral 
B) -1 
C) -2 
D) +1 
E) +2

Question 7

Why is the formation of iron hydroxide, Fe   , from   and O   not considered an oxidation-reduction reaction?

Accepted Answer

A) The iron is only oxidized and nothing is reduced. 
B) The iron is only reduced, not oxidized. 
C) The   ion is not changed during this chemical reaction. 
D) Iron can never be oxidized or reduced. 
A) The iron is only oxidized and nothing is reduced. 
B) The iron is only reduced, not oxidized. 
C) The   ion is not changed during this chemical reaction. 
D) Iron can never be oxidized or reduced.

Question 8

In a battery, if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn
What reaction would be taking place if you were charging the battery?

Accepted Answer

A) 2 MnO2 + Zn → Mn2O3 + ZnO 
B) ZnO → Zn 
C) Mn2O3 → MnO2 
D) all of the above 
E) none of the above 
A) 2 MnO2 + Zn → Mn2O3 + ZnO 
B) ZnO → Zn 
C) Mn2O3 → MnO2 
D) all of the above 
E) none of the above

Question 9

In a battery, the following oxidation-reduction reaction is taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is undergoing reduction as written?

Accepted Answer

A) Zn 
B) ZnO 
C) MnO2 
D) Mn2O3 
E) none of the above 
A) Zn 
B) ZnO 
C) MnO2 
D) Mn2O3 
E) none of the above

Question 10

The oxidation of iron to rust is a problem structural engineers need to be concerned about, but the oxidation of aluminum to aluminum oxide is not. Why?

Accepted Answer

A) Since aluminum is so light and inexpensive, it is easily replaced when corroded. 
B) Aluminum oxide is insoluble in water and thus forms a protective coating that prevents continued oxidation of the aluminum. 
C) Aluminum oxide is even stronger than aluminum. 
D) The oxidation of aluminum is a very slow reaction, taking hundreds of years before any structural changes are noticed. 
A) Since aluminum is so light and inexpensive, it is easily replaced when corroded. 
B) Aluminum oxide is insoluble in water and thus forms a protective coating that prevents continued oxidation of the aluminum. 
C) Aluminum oxide is even stronger than aluminum. 
D) The oxidation of aluminum is a very slow reaction, taking hundreds of years before any structural changes are noticed.

Question 11

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na+

Accepted Answer

A) 2 electrons are lost 
B) 1/2 electron is gained 
C) 1/2 electron is lost 
D) 2 electrons are gained 
E) 4 electrons are gained 
A) 2 electrons are lost 
B) 1/2 electron is gained 
C) 1/2 electron is lost 
D) 2 electrons are gained 
E) 4 electrons are gained

Question 12

When boron is added to a layer of ultrapure silicon, the result is ________.

Accepted Answer

A) n-type silicon 
B) p-type silicon 
C) an excess of negative charges 
D) electrons that are free to roam 
E) A and C 
A) n-type silicon 
B) p-type silicon 
C) an excess of negative charges 
D) electrons that are free to roam 
E) A and C

Question 13

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O
What is the fuel ?

Accepted Answer

A) H2 
B) O2 
C) H2O 
D) all of the above 
E) none of the above 
A) H2 
B) O2 
C) H2O 
D) all of the above 
E) none of the above

Question 14

How would you purify a metal sulfide?

Accepted Answer

A) react it with oxygen at high temperature 
B) react it with a reducing agent at high temperatures 
C) roast it with carbon 
D) mix it with slag and heat 
E) none of the above 
A) react it with oxygen at high temperature 
B) react it with a reducing agent at high temperatures 
C) roast it with carbon 
D) mix it with slag and heat 
E) none of the above

Question 15

Electrolysis is an example of ________.

Accepted Answer

A) a physical change 
B) a chemical change 
C) an acid-base reaction 
D) an exothermic reaction 
A) a physical change 
B) a chemical change 
C) an acid-base reaction 
D) an exothermic reaction

Question 16

What is the purpose of the salt bridge in a voltaic cell?

Accepted Answer

A) to prevent any further migration of electrons through the wire 
B) to allow for the build up of positively charged ions in one container and negatively charged ions in the other container 
C) to allow the   and the   to flow freely between the two containers 
D) to allow for a balance of charge between the two chambers 
A) to prevent any further migration of electrons through the wire 
B) to allow for the build up of positively charged ions in one container and negatively charged ions in the other container 
C) to allow the   and the   to flow freely between the two containers 
D) to allow for a balance of charge between the two chambers

Question 17

Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O2 → 2 Fe2O3
What is happening at the cathodic region?

Accepted Answer

A) Iron is being oxidized. 
B) Oxygen is being oxidized. 
C) Oxygen is being reduced 
D) Iron is being reduced. 
E) none of the above 
A) Iron is being oxidized. 
B) Oxygen is being oxidized. 
C) Oxygen is being reduced 
D) Iron is being reduced. 
E) none of the above

Question 18

The following set of redox reactions takes place as shown.   If you had two containers filled with the ion solution described above with a wire connecting a piece of iron (in container A)and a piece of copper (in container B)and a salt-bridge connecting the two containers, which way do the positive ions in the salt-bridge flow?

Accepted Answer

A) There is no flow of positive ions in the salt-bridge 
B) The positive ions flow from container A to container B. 
C) The positive ions flow from container B to container A. 
D) The positive ions flow back and forth between the two containers. 
E) The ions only move in the containers they originate in. 
A) There is no flow of positive ions in the salt-bridge 
B) The positive ions flow from container A to container B. 
C) The positive ions flow from container B to container A. 
D) The positive ions flow back and forth between the two containers. 
E) The ions only move in the containers they originate in.

Question 19

Zinc, Zn, is more easily oxidized than copper, Cu. Two strips of these metals are placed within separate salt solutions and then connected by a wire. Does an electric current pass through this wire?

Accepted Answer

A) Yes, as the zinc is oxidized in the salt solution, its released electrons pass through the wire producing an electric current. 
B) No, an electric current does not pass through the wire because this would result in a prohibitive build up of charge. 
C) Yes and No. The passage of an electric current depends on whether the salt solutions are sufficiently concentrated to cause the oxidation of the zinc metal. The answer is yes only if the salt solution concentration is greater than 1M. 
D) There is insufficient information given to know. The passage of electric current depends on three things: the size of the plates, the concentration of the salt solution, and the gauge of the wire. 
A) Yes, as the zinc is oxidized in the salt solution, its released electrons pass through the wire producing an electric current. 
B) No, an electric current does not pass through the wire because this would result in a prohibitive build up of charge. 
C) Yes and No. The passage of an electric current depends on whether the salt solutions are sufficiently concentrated to cause the oxidation of the zinc metal. The answer is yes only if the salt solution concentration is greater than 1M. 
D) There is insufficient information given to know. The passage of electric current depends on three things: the size of the plates, the concentration of the salt solution, and the gauge of the wire.

Question 20

Aluminum metal undergoes the same basic corrosion process that iron does yet it does not decompose as rapidly. Why?

Accepted Answer

A) The aluminum oxide does not flake off like rust and acts as a protective layer. 
B) Aluminum is harder to oxidize than iron. 
C) Aluminum is harder to reduce than iron. 
D) The aluminum oxide product undergoes a reduction to produce aluminum metal. 
E) The aluminum is galvanized, which prevents oxidation. 
A) The aluminum oxide does not flake off like rust and acts as a protective layer. 
B) Aluminum is harder to oxidize than iron. 
C) Aluminum is harder to reduce than iron. 
D) The aluminum oxide product undergoes a reduction to produce aluminum metal. 
E) The aluminum is galvanized, which prevents oxidation.

Which of the following materials is most likely to undergo oxidation?

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

What correlation might you expect between an element's ionization energy and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

What correlation might you expect between an element's electronegativity and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

Which of the following elements would be most useful for creating a p-type silicon?

The charge on the sulfur in the compound copper sulfide, Cu₂S, is ________.

Why is the formation of iron hydroxide, Fe , from and O not considered an oxidation-reduction reaction?

In a battery, if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

In a battery, the following oxidation-reduction reaction is taking place: Mn₂O₃ + ZnO → 2 MnO₂+ Zn What is undergoing reduction as written?

The oxidation of iron to rust is a problem structural engineers need to be concerned about, but the oxidation of aluminum to aluminum oxide is not. Why?

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na⁺

When boron is added to a layer of ultrapure silicon, the result is ________.

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H₂ + O₂ → 2 H₂O What is the fuel ?

How would you purify a metal sulfide?

Electrolysis is an example of ________.

What is the purpose of the salt bridge in a voltaic cell?

Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O₂ → 2 Fe₂O₃ _{What is happening at the cathodic region?}

Zinc, Zn, is more easily oxidized than copper, Cu. Two strips of these metals are placed within separate salt solutions and then connected by a wire. Does an electric current pass through this wire?

Aluminum metal undergoes the same basic corrosion process that iron does yet it does not decompose as rapidly. Why?

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Exam 11: Oxidations and Reductions Charge the World

Which of the following materials is most likely to undergo oxidation?

Why does a battery that has thick zinc walls last longer than one that has thin zinc walls?

What correlation might you expect between an element's ionization energy and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

What correlation might you expect between an element's electronegativity and its ability to behave as an oxidizing agent? How about its ability to behave as a reducing agent?

Which of the following elements would be most useful for creating a p-type silicon?

The charge on the sulfur in the compound copper sulfide, Cu2S, is ________.

Why is the formation of iron hydroxide, Fe , from and O not considered an oxidation-reduction reaction?

In a battery, if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn What reaction would be taking place if you were charging the battery?

In a battery, the following oxidation-reduction reaction is taking place: Mn2O3 + ZnO → 2 MnO2 + Zn What is undergoing reduction as written?

The oxidation of iron to rust is a problem structural engineers need to be concerned about, but the oxidation of aluminum to aluminum oxide is not. Why?

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na+

When boron is added to a layer of ultrapure silicon, the result is ________.

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O What is the fuel ?

How would you purify a metal sulfide?

Electrolysis is an example of ________.

What is the purpose of the salt bridge in a voltaic cell?

Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O2 → 2 Fe2O3 What is happening at the cathodic region?

Zinc, Zn, is more easily oxidized than copper, Cu. Two strips of these metals are placed within separate salt solutions and then connected by a wire. Does an electric current pass through this wire?

Aluminum metal undergoes the same basic corrosion process that iron does yet it does not decompose as rapidly. Why?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

How Chemicals React

Acids and Bases in Our Environment

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

The charge on the sulfur in the compound copper sulfide, Cu₂S, is ________.

In a battery, if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

In a battery, the following oxidation-reduction reaction is taking place: Mn₂O₃ + ZnO → 2 MnO₂+ Zn What is undergoing reduction as written?

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na⁺

In one type of fuel cell the following oxidation-reduction reactions are taking place: 2 H₂ + O₂ → 2 H₂O What is the fuel ?

Rust has a tendency to form when iron in contact with water reacts according to the following reaction: 4 Fe + 3 O₂ → 2 Fe₂O₃ _{What is happening at the cathodic region?}