Question 1

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

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 2

If the pH of a solution is 10,what is the hydronium ion concentration?

Accepted Answer

A) 1 × 10-10 M 
B) 1 × 1010 M 
C) 10 M 
D) -10 M 
E) - 1 × 1010 M 
A) 1 × 10-10 M 
B) 1 × 1010 M 
C) 10 M 
D) -10 M 
E) - 1 × 1010 M

Question 3

Which of the following statements is untrue about oxidation and reduction processes?

Accepted Answer

A) An oxidation can happen without a reduction. 
B) It involves the exchange of electrons. 
C) Often ions are generated or consumed. 
D) Electrons are often involved in oxidation and reduction reactions. 
E) All of the above are true. 
A) An oxidation can happen without a reduction. 
B) It involves the exchange of electrons. 
C) Often ions are generated or consumed. 
D) Electrons are often involved in oxidation and reduction reactions. 
E) All of the above are true.

Question 4

Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?

Accepted Answer

A) The pH of the battery fluid has increased. 
B) The pH of the battery fluid has decreased. 
C) The pH of the battery fluid does not change. 
D) Since the lights were left on and the battery is dead,the pH of the battery fluid must be zero. 
A) The pH of the battery fluid has increased. 
B) The pH of the battery fluid has decreased. 
C) The pH of the battery fluid does not change. 
D) Since the lights were left on and the battery is dead,the pH of the battery fluid must be zero.

Question 5

Hydrogen sulfide,H2S,burns in the presence of oxygen, $\mathrm { O } _ { 2 }$ ,to produce water, $\mathrm { H } _ { 2 }$ O,and sulfur dioxide,SO2.Through this reaction,is sulfur oxidized or reduced? 2 $\mathrm { H } _ { 2 }$ S + 3 $\mathrm { O } _ { 2 }$ ? 2 $\mathrm { H } _ { 2 }$ O + 2 $\mathrm { SO } _ { 2 }$

Accepted Answer

A) Sulfur is reduced. 
B) Sulfur is oxidized. 
C) Sulfur is both oxidized and reduced. 
D) Sulfur is neither oxidized nor reduced. 
A) Sulfur is reduced. 
B) Sulfur is oxidized. 
C) Sulfur is both oxidized and reduced. 
D) Sulfur is neither oxidized nor reduced.

Question 6

Glucose, $\mathrm { C } _ { 6 } \mathrm { H } _ { 12 } \mathrm { O } _ { 6 }$ ,is a simple sugar that the body metabolizes into two molecules of pyruvic acid, $\mathrm { C } _ { 3 } \mathrm { H } _ { 4 } \mathrm { O } _ { 3 }$ .Is the glucose oxidized or reduced as it transforms into pyruvic acid?

Accepted Answer

A) The glucose is oxidized. 
B) The glucose is reduced. 
C) Parts of the glucose molecule are oxidized while others are reduced. 
D) Glucose is neither oxidized or reduced as it transforms into pyruvic acid. 
A) The glucose is oxidized. 
B) The glucose is reduced. 
C) Parts of the glucose molecule are oxidized while others are reduced. 
D) Glucose is neither oxidized or reduced as it transforms into pyruvic acid.

Question 7

In the reaction below,what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3

Accepted Answer

A) It means that the forward and backward reactions are happening at the same time. 
B) It means that the reaction cannot decide which way to go. 
C) It means that the forward reaction does not progress. 
D) It means that the backward reaction happens as fast as the forward reaction and so the proton is not transferred at all. 
E) none of the above 
A) It means that the forward and backward reactions are happening at the same time. 
B) It means that the reaction cannot decide which way to go. 
C) It means that the forward reaction does not progress. 
D) It means that the backward reaction happens as fast as the forward reaction and so the proton is not transferred at all. 
E) none of the above

Question 8

The amphoteric reaction between two water molecules is endothermic,which means that this reaction requires the input of energy in order to proceed: Energy + $\mathrm { H } _ { 2 }$ O + $\mathrm { H } _ { 2 }$ O ? $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ + O $\mathrm { H } ^ { - }$ The warmer the temperature of the water,the more thermal energy is available for this reaction,and the more hydronium and hydroxide ions are formed.Based on this information,should the value of $\mathrm { K } _ { \mathrm { W } }$ be expected to increase,decrease,or stay the same with increasing temperature?

Accepted Answer

A) The value of $\mathrm { K } _ { \mathrm { W } }$ will stay the same,since it is a constant. 
B) The value of $\mathrm { K } _ { \mathrm { W } }$ will decrease,since there are more hydronium ions than hydroxide ions. 
C) The value of $\mathrm { K } _ { \mathrm { W } }$ will increase since the rise in temperature allows for a higher concentration of both ions. 
D) The value of $\mathrm { K } _ { \mathrm { W } }$ 
A) The value of $\mathrm { K } _ { \mathrm { W } }$ will stay the same,since it is a constant. 
B) The value of $\mathrm { K } _ { \mathrm { W } }$ will decrease,since there are more hydronium ions than hydroxide ions. 
C) The value of $\mathrm { K } _ { \mathrm { W } }$ will increase since the rise in temperature allows for a higher concentration of both ions. 
D) The value of $\mathrm { K } _ { \mathrm { W } }$

Question 9

What is the source of acid rain?

Accepted Answer

A) Acid rain is from dissolved carbon dioxide. 
B) All rain is acid rain because rain has a pH is less than 7. 
C) Rain is normally basic,but depending on the weather it can get slightly acidic. 
D) All rain is acid rain because rain has a hydronium ion concentration greater than 10-7 M. 
E) none of the above 
A) Acid rain is from dissolved carbon dioxide. 
B) All rain is acid rain because rain has a pH is less than 7. 
C) Rain is normally basic,but depending on the weather it can get slightly acidic. 
D) All rain is acid rain because rain has a hydronium ion concentration greater than 10-7 M. 
E) none of the above

Question 10

What is an acid?

Accepted Answer

A) anything that donates hydrogen ions 
B) anything that accepts hydrogen atoms 
C) anything that donates hydrogen atoms 
D) anything that dissolves metal 
E) anything that donates hydronium ions 
A) anything that donates hydrogen ions 
B) anything that accepts hydrogen atoms 
C) anything that donates hydrogen atoms 
D) anything that dissolves metal 
E) anything that donates hydronium ions

Question 11

How is electrolysis different from what is going on chemically inside a battery?

Accepted Answer

A) They are the same process,just reversed. 
B) Electrolysis does not use electrons. 
C) Electrolysis only uses electrons from a cathode. 
D) You cannot make pure compounds with electrolysis. 
E) You do not produce a chemical change in electrolysis. 
A) They are the same process,just reversed. 
B) Electrolysis does not use electrons. 
C) Electrolysis only uses electrons from a cathode. 
D) You cannot make pure compounds with electrolysis. 
E) You do not produce a chemical change in electrolysis.

Question 12

How does connecting a metal like iron with a wire to a metal that is easier to oxidize like zinc help prevent corrosion of the iron?

Accepted Answer

A) The other metal is oxidized instead and the electrons travel to the iron,keeping it from oxidizing. 
B) The other metal absorbs the electrons from the iron,which keeps the iron from undergoing oxidation. 
C) The wire is acting as an oxidant and keeps the two metals from undergoing other chemical reactions. 
D) There is no salt-bridge,so there is no reaction between the two metals. 
E) The other metal is oxidized and adsorbs all the oxidant,keeping it away from the iron. 
A) The other metal is oxidized instead and the electrons travel to the iron,keeping it from oxidizing. 
B) The other metal absorbs the electrons from the iron,which keeps the iron from undergoing oxidation. 
C) The wire is acting as an oxidant and keeps the two metals from undergoing other chemical reactions. 
D) There is no salt-bridge,so there is no reaction between the two metals. 
E) The other metal is oxidized and adsorbs all the oxidant,keeping it away from the iron.

Question 13

In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn
What is being formed at the anode?

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 14

-Which of the above images represents a solution of the strongest acid (HA)?

Accepted Answer

A) A 
B) B 
C) C 
D) All of the above are strong acids. 
E) None of the above are strong acids. 
A) A 
B) B 
C) C 
D) All of the above are strong acids. 
E) None of the above are strong acids.

Question 15

Which of the following compounds would least likely act as an acid?

Accepted Answer

A) SO4-2 
B) HSO4-1 
C) H2SO4 
D) NH3 
E) CH3CO2H 
A) SO4-2 
B) HSO4-1 
C) H2SO4 
D) NH3 
E) CH3CO2H

Question 16

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

Accepted Answer

A) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = 3 M.It is impossible because it is hard to measure such a small amount of hydronium ions accurately. 
B) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = 30 M.It is impossible because pH can not be negative. 
C) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = $10 ^ { 30 }$ M.It is impossible because any container used to hold the acid would immediately corrode. 
D) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = $10 ^ { 3 }$ 
A) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = 3 M.It is impossible because it is hard to measure such a small amount of hydronium ions accurately. 
B) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = 30 M.It is impossible because pH can not be negative. 
C) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = $10 ^ { 30 }$ M.It is impossible because any container used to hold the acid would immediately corrode. 
D) Concentration of $\mathrm { H } _ { 3 }$ $\mathrm { O } ^ { + }$ = $10 ^ { 3 }$

Question 17

Which of the following statements is not true about a neutralization reaction?

Accepted Answer

A) Water is always formed in a neutralization reaction. 
B) One molecule of acid neutralizes one molecule of base. 
C) A neutralization is the reaction of a hydroxide ion with a proton. 
D) All of the above are true. 
E) None of the above are true. 
A) Water is always formed in a neutralization reaction. 
B) One molecule of acid neutralizes one molecule of base. 
C) A neutralization is the reaction of a hydroxide ion with a proton. 
D) All of the above are true. 
E) None of the above are true.

Question 18

Identify the acid or base behavior of each substance in these reactions: HSO4- + $\mathrm { H } _ { 2 }$ O ? O $\mathrm { H } ^ { - }$ + $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$

Accepted Answer

A) HSO4- acts as an acid, $\mathrm { H } _ { 2 }$ O acts as a base,O $\mathrm { H } ^ { - }$ acts as an acid, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a base. 
B) HSO4- acts as an base, $\mathrm { H } _ { 2 }$ O acts as a acid,O $\mathrm { H } ^ { - }$ acts as an acid, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a base. 
C) HSO4- acts as an acid, $\mathrm { H } _ { 2 }$ O acts as a base,O $\mathrm { H } ^ { - }$ acts as an base, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a acid. 
D) HSO4- acts as an base, $\mathrm { H } _ { 2 }$ O acts as a acid,O $\mathrm { H } ^ { - }$ acts as an base, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ 
A) HSO4- acts as an acid, $\mathrm { H } _ { 2 }$ O acts as a base,O $\mathrm { H } ^ { - }$ acts as an acid, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a base. 
B) HSO4- acts as an base, $\mathrm { H } _ { 2 }$ O acts as a acid,O $\mathrm { H } ^ { - }$ acts as an acid, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a base. 
C) HSO4- acts as an acid, $\mathrm { H } _ { 2 }$ O acts as a base,O $\mathrm { H } ^ { - }$ acts as an base, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$ acts as a acid. 
D) HSO4- acts as an base, $\mathrm { H } _ { 2 }$ O acts as a acid,O $\mathrm { H } ^ { - }$ acts as an base, $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$

Question 19

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 so much of a problem.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 20

Which of the following species is the oxidizing agent? 2 CuBr → 2Cu + Br2

Accepted Answer

A) Cu 
B) CuBr 
C) Cu+ 
D) Br- 
E) Br2 
A) Cu 
B) CuBr 
C) Cu+ 
D) Br- 
E) Br2

Exam 18: Two Classes of Chemical Reactions

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

If the pH of a solution is 10,what is the hydronium ion concentration?

Which of the following statements is untrue about oxidation and reduction processes?

Your car lights were left on while you were shopping,and now your car battery is dead.Has the pH of the battery fluid increased or decreased?

In the reaction below,what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3

What is the source of acid rain?

What is an acid?

How is electrolysis different from what is going on chemically inside a battery?

How does connecting a metal like iron with a wire to a metal that is easier to oxidize like zinc help prevent corrosion of the iron?

In a battery,the following oxidation-reduction reactions are taking place: Mn2O3 + ZnO → 2 MnO2 + Zn What is being formed at the anode?

-Which of the above images represents a solution of the strongest acid (HA)?

Which of the following compounds would least likely act as an acid?

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

Which of the following statements is not true about a neutralization reaction?

Identify the acid or base behavior of each substance in these reactions: HSO4- + H2\mathrm { H } _ { 2 }H2​ O ? O H−\mathrm { H } ^ { - }H− + H2\mathrm { H } _ { 2 }H2​ S O4\mathrm { O } _ { 4 }O4​

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 so much of a problem.Why?

Which of the following species is the oxidizing agent? 2 CuBr → 2Cu + Br2

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

How Chemicals React

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Time - Reading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: The Nature of Science

Filters

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

In the reaction below,what does the symbol ⇌ mean? OH^- + NH₄⁺ ⇌ H₂O + NH₃

In a battery,the following oxidation-reduction reactions are taking place: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What is being formed at the anode?

Identify the acid or base behavior of each substance in these reactions: HSO₄^- + $\mathrm { H } _ { 2 }$ O ? O $\mathrm { H } ^ { - }$ + $\mathrm { H } _ { 2 }$ S $\mathrm { O } _ { 4 }$

Which of the following species is the oxidizing agent? 2 CuBr → 2Cu + Br₂