Question 1

According to the following reaction,which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-

Accepted Answer

A) H2SO4 
B) H2O 
C) H3O+ 
D) HSO4- 
E) none of the above 
A) H2SO4 
B) H2O 
C) H3O+ 
D) HSO4- 
E) none of the above

Question 2

Water is 88.88 percent oxygen by mass.Oxygen is exactly what a fire needs to grow brighter and stronger.So why doesn't a fire grow brighter and stronger when water is added to it?

Accepted Answer

A) Oxygen in water is already "reduced" from the hydrogen atoms,so this oxygen atom no longer has a great attraction for additional electrons. 
B) The oxygen is chemically bound to hydrogen atoms. 
C) Oxygen in water is completely different from oxygen $\mathrm { O } _ { 2 }$ ,which is what is required for combustion. 
D) all of the above 
A) Oxygen in water is already "reduced" from the hydrogen atoms,so this oxygen atom no longer has a great attraction for additional electrons. 
B) The oxygen is chemically bound to hydrogen atoms. 
C) Oxygen in water is completely different from oxygen $\mathrm { O } _ { 2 }$ ,which is what is required for combustion. 
D) all of the above

Question 3

The following set of redox reactions takes place when iron is dipped into a solution of copper ions. Fe → Fe+2 + 2e-
Cu+2 + 2e- → Cu
Which of the following describes what is happening with the electrons in the solution?

Accepted Answer

A) The iron metal is releasing electrons and they are traveling to the copper ions. 
B) The copper is releasing electrons and they are traveling to the iron ions. 
C) The iron ions are gaining electrons from the copper metal. 
D) The copper ions are releasing electrons and they are traveling to the iron metal. 
E) none of the above 
A) The iron metal is releasing electrons and they are traveling to the copper ions. 
B) The copper is releasing electrons and they are traveling to the iron ions. 
C) The iron ions are gaining electrons from the copper metal. 
D) The copper ions are releasing electrons and they are traveling to the iron metal. 
E) none of the above

Question 4

What is the main characteristic of a strong base?

Accepted Answer

A) It is completely dissociated in water. 
B) It readily accepts an acidic proton. 
C) It is corrosive. 
D) It will damage your skin. 
E) all of the above 
A) It is completely dissociated in water. 
B) It readily accepts an acidic proton. 
C) It is corrosive. 
D) It will damage your skin. 
E) all of the above

Question 5

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

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 6

Sodium hydroxide,NaOH,is a strong base,which means that it readily accepts hydrogen ions.What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?

Accepted Answer

A) water and sodium hydroxide 
B) sodium hydroxide and hydronium ions 
C) sodium ions and hydronium ions 
D) sodium ions and water 
A) water and sodium hydroxide 
B) sodium hydroxide and hydronium ions 
C) sodium ions and hydronium ions 
D) sodium ions and water

Question 7

What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-1M? [H3O+] × [OH-] = Kw = 1 × 10-14

Accepted Answer

A) 1 × 10-3 
B) 1 × 10-2 
C) 1 × 10-4 
D) 1 × 1013 
E) none of the above 
A) 1 × 10-3 
B) 1 × 10-2 
C) 1 × 10-4 
D) 1 × 1013 
E) none of the above

Question 8

What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-5M? [H3O+] × [OH-] = Kw = 1 × 10-14

Accepted Answer

A) 1 × 10-14 
B) 1 × 10-5 
C) 1 × 109 
D) 1 × 105 
E) 1 × 10-9 
A) 1 × 10-14 
B) 1 × 10-5 
C) 1 × 109 
D) 1 × 105 
E) 1 × 10-9

Question 9

In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn + 2 OH- → ZnO + H2O + 2e-
Rxn B: 2 MnO2 + H2O + 2e- → Mn2O3 + 2 OH-
What is undergoing reduction?

Accepted Answer

A) Zn 
B) ZnO 
C) MnO2 
D) H2O 
E) OH- 
A) Zn 
B) ZnO 
C) MnO2 
D) H2O 
E) OH-

Question 10

According to the following reaction,which molecule is acting as a base? H3O+ + HSO4- → H2O + H2SO4

Accepted Answer

A) H2SO4 
B) H2O 
C) H3O+ 
D) HSO4- 
E) none of the above 
A) H2SO4 
B) H2O 
C) H3O+ 
D) HSO4- 
E) none of the above

Question 11

Qualitatively,what happens to the hydronium ion concentration if you increase the hydroxide ion concentration?

Accepted Answer

A) The concentration of H3O+ stays the same but the ratio changes. 
B) The concentration of H3O+ increases but the ratio stays the same. 
C) The concentration of H3O+ increases to neutralize the excess hydroxide. 
D) none of the above 
A) The concentration of H3O+ stays the same but the ratio changes. 
B) The concentration of H3O+ increases but the ratio stays the same. 
C) The concentration of H3O+ increases to neutralize the excess hydroxide. 
D) none of the above

Question 12

Chemical equations need to be balanced not only in terms of the number of atoms,but also by the charge.In other words,just as there should be the same number of atoms before and after the arrow of an equation,there should be the same charge.What set of coefficients is necessary to balance the following chemical equation? ________ $\mathrm { Ce } ^ { 4 + }$ + ________ Cl? ? ________ $\mathrm { Ce } ^ { 3 + }$ + ________ $\mathrm { Cl } _ { 2 }$

Accepted Answer

A) 1,2,1,1 
B) 2,2,2,1 
C) 1,4,1,2 
D) 3,4,3,2 
A) 1,2,1,1 
B) 2,2,2,1 
C) 1,4,1,2 
D) 3,4,3,2

Question 13

-In the above diagram,which atom is oxidized,the darker colored atom or the lighter colored atom?

Accepted Answer

A) Both of the atoms are oxidized. 
B) Neither of the atoms is oxidized. 
C) Only the darker colored atom is oxidized. 
D) Only the lighter colored atom is oxidized. 
A) Both of the atoms are oxidized. 
B) Neither of the atoms is oxidized. 
C) Only the darker colored atom is oxidized. 
D) Only the lighter colored atom is oxidized.

Question 14

Why might an area with a large amount of limestone (CaCO3)be less susceptible to acid rain?

Accepted Answer

A) The acid in the rain is neutralized by the natural base in the limestone. 
B) The rain travels quickly through the porous limestone and therefore the rate of reaction is slower. 
C) Limestone is degraded by acid rain and therefore acid rain has the same damaging effects. 
D) Only acid rain made from sulfur compounds reacts with the limestone. 
E) none of the above 
A) The acid in the rain is neutralized by the natural base in the limestone. 
B) The rain travels quickly through the porous limestone and therefore the rate of reaction is slower. 
C) Limestone is degraded by acid rain and therefore acid rain has the same damaging effects. 
D) Only acid rain made from sulfur compounds reacts with the limestone. 
E) none of the above

Question 15

For the following acid-base reaction,identify what is formed in the space marked. HF + KOH ⇌ ???? + H2O

Accepted Answer

A) KF 
B) H3OF 
C) KOH2 
D) KOH2F 
E) none of the above 
A) KF 
B) H3OF 
C) KOH2 
D) KOH2F 
E) none of the above

Question 16

Upon ingestion,grain alcohol, $\mathrm { C } _ { 2 }$ $\mathrm { H } _ { 6 }$ O,is metabolized into acetaldehyde, $\mathrm { C } _ { 2 }$ $\mathrm { H } _ { 4 }$ O,which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?

Accepted Answer

A) The grain alcohol is reduced. 
B) The grain alcohol is oxidized. 
C) Some of the grain alcohol is oxidized and some is reduced to other products. 
D) The grain alcohol is neither oxidized nor reduced. 
A) The grain alcohol is reduced. 
B) The grain alcohol is oxidized. 
C) Some of the grain alcohol is oxidized and some is reduced to other products. 
D) The grain alcohol is neither oxidized nor reduced.

Question 17

One of the products of combustion is water.Why doesn't this water extinguish the combustion?

Accepted Answer

A) While areas of combustion are being extinguished,new areas are combusting. 
B) Combustion only produces micro amounts of water. 
C) The chemical combustion reaction is happening too fast for the water to have an effect on the fire. 
D) This water is in the gaseous phase and merely floats away from the fire. 
A) While areas of combustion are being extinguished,new areas are combusting. 
B) Combustion only produces micro amounts of water. 
C) The chemical combustion reaction is happening too fast for the water to have an effect on the fire. 
D) This water is in the gaseous phase and merely floats away from the fire.

Exam 18: Two Classes of Chemical Reactions

According to the following reaction,which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-

Water is 88.88 percent oxygen by mass.Oxygen is exactly what a fire needs to grow brighter and stronger.So why doesn't a fire grow brighter and stronger when water is added to it?

The following set of redox reactions takes place when iron is dipped into a solution of copper ions. Fe → Fe+2 + 2e- Cu+2 + 2e- → Cu Which of the following describes what is happening with the electrons in the solution?

What is the main characteristic of a strong base?

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

Sodium hydroxide,NaOH,is a strong base,which means that it readily accepts hydrogen ions.What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?

What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-1M? [H3O+] × [OH-] = Kw = 1 × 10-14

What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-5M? [H3O+] × [OH-] = Kw = 1 × 10-14

In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn + 2 OH- → ZnO + H2O + 2e- Rxn B: 2 MnO2 + H2O + 2e- → Mn2O3 + 2 OH- What is undergoing reduction?

According to the following reaction,which molecule is acting as a base? H3O+ + HSO4- → H2O + H2SO4

Qualitatively,what happens to the hydronium ion concentration if you increase the hydroxide ion concentration?

-In the above diagram,which atom is oxidized,the darker colored atom or the lighter colored atom?

Why might an area with a large amount of limestone (CaCO3)be less susceptible to acid rain?

For the following acid-base reaction,identify what is formed in the space marked. HF + KOH ⇌ ???? + H2O

One of the products of combustion is water.Why doesn't this water extinguish the combustion?

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

According to the following reaction,which molecule is acting as an acid? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

The following set of redox reactions takes place when iron is dipped into a solution of copper ions. Fe → Fe⁺² + 2e- Cu⁺² + 2e- → Cu Which of the following describes what is happening with the electrons in the solution?

What would the concentration of H₃O⁺ be if the concentration of OH^- was 1 × 10^-1M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-1⁴

What would the concentration of OH^- be if the concentration of H₃O⁺ was 1 × 10^-⁵M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

In a battery,the following two oxidation-reduction reactions are taking place: rxn A: Zn + 2 OH^- → ZnO + H₂O + 2e^- Rxn B: 2 MnO₂ + H₂O + 2e^- → Mn₂O₃+ 2 OH^- What is undergoing reduction?

According to the following reaction,which molecule is acting as a base? H₃O⁺ + HSO₄^- → H₂O + H₂SO₄

Why might an area with a large amount of limestone (CaCO₃)be less susceptible to acid rain?

For the following acid-base reaction,identify what is formed in the space marked. HF + KOH ⇌ ???? + H₂O