Question 1

Which is most often used in the laboratory to measure pH?

Accepted Answer

A) a standard hydrogen electrode 
B) a glass electrode 
C) a Daniell cell 
D) a conductivity cell 
A) a standard hydrogen electrode 
B) a glass electrode 
C) a Daniell cell 
D) a conductivity cell

Question 2

Shown below is an electrochemical cell with anode a and cathode c.Both the anode and the cathode are inert electrodes.The liquid shown in compartment b of the cell is molten potassium chloride,KCl(l).  
-Determine the direction of electron flow and the direction of ion flow.

Accepted Answer

A) Electrons flow from a to c;K+ ions flow toward a and Cl- ions flow toward c. 
B) Electrons flow from a to c;Cl- ions flow toward a and K+ ions flow toward c. 
C) Electrons flow from c to a;K+ ions flow toward a and Cl- ions flow toward c. 
D) Electrons flow from c to a;Cl- ions flow toward a and K+ ions flow toward c. 
A) Electrons flow from a to c;K+ ions flow toward a and Cl- ions flow toward c. 
B) Electrons flow from a to c;Cl- ions flow toward a and K+ ions flow toward c. 
C) Electrons flow from c to a;K+ ions flow toward a and Cl- ions flow toward c. 
D) Electrons flow from c to a;Cl- ions flow toward a and K+ ions flow toward c.

Question 3

Shown below is a galvanic cell with anode compartment b containing anode a and cathode compartment d containing cathode c.Electrons flow through wire f,ions flow through salt bridge e,and the cell potential is read using voltmeter g.
This galvanic cell uses the reaction: Cu(s)+ 2 AgS1U1P1+S1S1P0(aq) $\rarr$ 2 Ag(s)+ CuS1U1P12+S1S1P0(aq).  
-Identify the anode and cathode half-reactions and categorize each as either oxidation or reduction.

Accepted Answer

A) Anode reaction: Ag+(aq)+ e- → Ag(s)(oxidation) Cathode reaction: Cu(s)→ Cu2+(aq)+ 2e- (reduction) 
B) Anode reaction: Ag+(aq)+ e- → Ag(s)(reduction) Cathode reaction: Cu(s)→ Cu2+(aq)+ 2e- (oxidation) 
C) Anode reaction: Cu(s)→ Cu2+(aq)+ 2e- (oxidation) Cathode reaction: Ag+(aq)+ e- → Ag(s)(reduction) 
D) Anode reaction: Cu(s)→ Cu2+(aq)+ 2e- (reduction) Cathode reaction: Ag+(aq)+ e- → Ag(s)(oxidation) 
A) Anode reaction: Ag+(aq)+ e- → Ag(s)(oxidation) Cathode reaction: Cu(s)→ Cu2+(aq)+ 2e- (reduction) 
B) Anode reaction: Ag+(aq)+ e- → Ag(s)(reduction) Cathode reaction: Cu(s)→ Cu2+(aq)+ 2e- (oxidation) 
C) Anode reaction: Cu(s)→ Cu2+(aq)+ 2e- (oxidation) Cathode reaction: Ag+(aq)+ e- → Ag(s)(reduction) 
D) Anode reaction: Cu(s)→ Cu2+(aq)+ 2e- (reduction) Cathode reaction: Ag+(aq)+ e- → Ag(s)(oxidation)

Question 4

Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid,H2CrO4.What current is required to deposit chromium at a rate of 1.25 g/min?

Accepted Answer

A) 38.1 A 
B) 38.7 A 
C) 116 A 
D) 232 A 
A) 38.1 A 
B) 38.7 A 
C) 116 A 
D) 232 A

Question 5

Doubling all the coefficients in the equation for the cell reaction

Accepted Answer

A) doubles both E° and ΔG°. 
B) doubles E°,but does not change ΔG°. 
C) doubles ΔG°,but does not change E°. 
D) does not change E° or ΔG°. 
A) doubles both E° and ΔG°. 
B) doubles E°,but does not change ΔG°. 
C) doubles ΔG°,but does not change E°. 
D) does not change E° or ΔG°.

Question 6

The cell reaction for a dry cell battery is
Zn(s)+ 2 MnO2(s)+ 2 NH4+(aq)→ 2 NH3(aq)+ Mn2O3(s)+ Zn2+(aq)+ H2O(l).
The standard cell potential for this cell is 1.56 V.What is the standard free energy change for this cell?

Accepted Answer

A) +151 kJ 
B) -151 kJ 
C) -301 kJ 
D) -602 kJ 
A) +151 kJ 
B) -151 kJ 
C) -301 kJ 
D) -602 kJ

Question 7

Based on the half-reactions and their respective standard reduction potentials below,the strongest reducing agent is ________,and the strongest oxidizing agent is ________.
Ag+(aq)+ e- → Ag(s)0.80 V
2 H+(aq)+ 2 e- → H2(g)0.00 V
Cd2+(aq)+ 2 e- → Cd(s)-0.40 V

Accepted Answer

A) Ag,Cd2+ 
B) Ag+,Cd 
C) Cd,Ag+ 
D) Cd2+,Ag 
A) Ag,Cd2+ 
B) Ag+,Cd 
C) Cd,Ag+ 
D) Cd2+,Ag

Question 8

A particular 12V battery is based on a reaction having a standard cell potential,E° = +1.92 V.What happens when the battery "dies"?

Accepted Answer

A) E° = 0 V and E = 0 V 
B) E° = 0 V and E = 12 V 
C) E° = +1.92 V and E = 0 V 
D) E° = +1.92 V and E = 12 V 
A) E° = 0 V and E = 0 V 
B) E° = 0 V and E = 12 V 
C) E° = +1.92 V and E = 0 V 
D) E° = +1.92 V and E = 12 V

Question 9

Shown below is a galvanic cell with anode compartment b containing anode a and cathode compartment d containing cathode c.Electrons flow through wire f,ions flow through salt bridge e,and the cell potential is read using voltmeter g.
This galvanic cell uses the reaction: Cu(s)+ 2 AgS1U1P1+S1S1P0(aq) $\rarr$ 2 Ag(s)+ CuS1U1P12+S1S1P0(aq).  
-NaNO3(aq)is employed in the salt bridge.Give the direction of electron flow and the direction of ion flow from the salt bridge.

Accepted Answer

A) Electrons flow from a to c;Na+ flows into b and NO3- flows into d. 
B) Electrons flow from a to c;NO3- flows into b and Na+ flows into d. 
C) electrons flow from c to a;Na+ flows into b and NO3- flows into d. 
D) Electrons flow from c to a;NO3- flows into b and Na+ flows into d. 
A) Electrons flow from a to c;Na+ flows into b and NO3- flows into d. 
B) Electrons flow from a to c;NO3- flows into b and Na+ flows into d. 
C) electrons flow from c to a;Na+ flows into b and NO3- flows into d. 
D) Electrons flow from c to a;NO3- flows into b and Na+ flows into d.

Question 10

The two half-reactions that are used in the direct methanol fuel cell are shown below.
I.2 CH3OH(aq)+ 2 H2O(l)→ 2 CO2(g)+ 12 H+(aq)+ 12 e-
II.3 O2(g)+ 12 H+(aq)+ 12 e- → 6 H2O(l)
The electrode at which half-reaction I occurs is the ________ at which ________ is oxidized,and half-reaction II occurs at the ________ at which ________ is reduced.

Accepted Answer

anode,CH₃OH

Question 11

For a galvanic cell,the cathode has a ________ sign and is the site of ________.

Accepted Answer

A) negative,oxidation 
B) negative,reduction 
C) positive,oxidation 
D) positive,reduction 
A) negative,oxidation 
B) negative,reduction 
C) positive,oxidation 
D) positive,reduction

Question 12

The chlor-alkali industry is based on the electrolysis of aqueous NaCl.What are the products of this electrolysis?

Accepted Answer

A) Na and Cl2 
B) NaOH,H2,and O2 
C) NaOH,H2,and Cl2 
D) NaOH,O2,and Cl2 
A) Na and Cl2 
B) NaOH,H2,and O2 
C) NaOH,H2,and Cl2 
D) NaOH,O2,and Cl2

Question 13

The following cell has a potential of 0.45 V at 25°C.
Pt(s)∣ H2(1 atm)|H+(? M)∣∣ Cl-(1 M)∣ Hg2Cl2(s)|Hg(l)
The standard half-cell potential for the half-reaction Hg2Cl2(s)+ 2 e- → 2 Hg(l)+ 2 Cl-(aq)is 0.28 V.What is the pH in the anode compartment?

Accepted Answer

A) 2)9 
B) 4)7 
C) 7)6 
D) 12.3 
A) 2)9 
B) 4)7 
C) 7)6 
D) 12.3

Question 14

-The cell reaction 2 Fe3+(aq)+ Zn(s)→ Zn2+(aq)+ 2 Fe2+(aq)occurs in the galvanic cell shown above.Which would be the most appropriate choices for the solid electrode in half-cell (A)and in half-cell (B)?

Accepted Answer

A) Fe(s)for half-cell (
A) and Zn(s)for half-cell (
B)  
B) Pt(s)for half-cell (
A) and Zn(s)for half-cell (
B)  
C) Fe(s)for half-cell (
A) and Fe(s)for half-cell (
B)  
D) Zn(s)for half-cell (
A) and Pt(s)for half-cell (
B)  
A) Fe(s)for half-cell (
A) and Zn(s)for half-cell (
B)  
B) Pt(s)for half-cell (
A) and Zn(s)for half-cell (
B)  
C) Fe(s)for half-cell (
A) and Fe(s)for half-cell (
B)  
D) Zn(s)for half-cell (
A) and Pt(s)for half-cell (
B)

Question 15

O2(g)+ 4 H+(aq)+ 4 e- → 2 H2O(l)E° = +1.23 V
Pb2+(aq)+ 2 e- → Pb(s)E° = -0.13 V
2 H2O(l)+ 2 e- → H2(g)+ 2 OH-(aq)E° = -0.83 V
Based on the half-reactions above,electrolysis of an aqueous solution of Pb(NO3)2 is expected to produce.

Accepted Answer

A) Pb at the cathode and H2 at the anode. 
B) Pb at the cathode and O2 at the anode. 
C) H2 at the cathode and Pb at the anode. 
D) O2 at the cathode and Pb at the anode. 
A) Pb at the cathode and H2 at the anode. 
B) Pb at the cathode and O2 at the anode. 
C) H2 at the cathode and Pb at the anode. 
D) O2 at the cathode and Pb at the anode.

Question 16

Galvanized steel is steel coated with a layer of

Accepted Answer

A) Fe2O3. 
B) Mg. 
C) Sn. 
D) Zn. 
A) Fe2O3. 
B) Mg. 
C) Sn. 
D) Zn.

Question 17

Consider the galvanic cell shown below.  
-What is the balanced equation for the cell reaction?

Accepted Answer

A) 2 Al(s)+ 3 Co(s)→ 2 Al3+(aq)+ 3 Co2+(aq) 
B) 2 Al3+(aq)+ 3 Co2+(aq)→ 2 Al(s)+ 3 Co(s) 
C) 2 Al(s)+ 3 Co2+(aq)→ 2 Al3+(aq)+ 3 Co(s) 
D) 2 Al3+(aq)+ 3 Co(s)→ 2 Al(s)+ 3 Co2+(aq) 
A) 2 Al(s)+ 3 Co(s)→ 2 Al3+(aq)+ 3 Co2+(aq) 
B) 2 Al3+(aq)+ 3 Co2+(aq)→ 2 Al(s)+ 3 Co(s) 
C) 2 Al(s)+ 3 Co2+(aq)→ 2 Al3+(aq)+ 3 Co(s) 
D) 2 Al3+(aq)+ 3 Co(s)→ 2 Al(s)+ 3 Co2+(aq)

Question 18

Consider the following galvanic cell.  
-Identify the anode and cathode,and indicate the direction of Na+ ion and NO3- ion flow from the salt bridge.

Accepted Answer

A) Fe is the anode and Sn is the cathode;Na+ ions flow into half-cell compartment (
A) and NO3- ions flow into half-cell compartment (
B) . 
B) Fe is the anode and Sn is the cathode;NO3- ions flow into half-cell compartment (
A) and Na+ ions flow into half-cell compartment (
B) . 
C) Sn is the anode and Fe is the cathode;Na+ ions flow into half-cell compartment (
A) and NO3- ions flow into half-cell compartment (
B) . 
D) Sn is the anode and Fe is the cathode;NO3- ions flow into half-cell compartment (
A) and Na+ ions flow into half-cell compartment (
B) . 
A) Fe is the anode and Sn is the cathode;Na+ ions flow into half-cell compartment (
A) and NO3- ions flow into half-cell compartment (
B) . 
B) Fe is the anode and Sn is the cathode;NO3- ions flow into half-cell compartment (
A) and Na+ ions flow into half-cell compartment (
B) . 
C) Sn is the anode and Fe is the cathode;Na+ ions flow into half-cell compartment (
A) and NO3- ions flow into half-cell compartment (
B) . 
D) Sn is the anode and Fe is the cathode;NO3- ions flow into half-cell compartment (
A) and Na+ ions flow into half-cell compartment (
B) .

Question 19

A galvanic cell consists of one half-cell that contains Ag(s)and Ag+(aq),and one half-cell that contains Cu(s)and Cu2+(aq).What species are produced at the electrodes under standard conditions?
Ag+(aq)+ e- → Ag(s)E° = +0.80 V
Cu2+(aq)+ 2 e- → Cu(s)E° = +0.34 V

Accepted Answer

A) Ag(aq)is formed at the cathode and,Cu(s)is formed at the anode. 
B) Ag(s)is formed at the cathode,and Cu2+(aq)is formed at the anode. 
C) Cu(s)is formed at the cathode,and Ag+(aq)is formed at the anode. 
D) Cu2+(aq)is formed at the cathode,and Cu(s)is formed at the anode. 
A) Ag(aq)is formed at the cathode and,Cu(s)is formed at the anode. 
B) Ag(s)is formed at the cathode,and Cu2+(aq)is formed at the anode. 
C) Cu(s)is formed at the cathode,and Ag+(aq)is formed at the anode. 
D) Cu2+(aq)is formed at the cathode,and Cu(s)is formed at the anode.

Question 20

The equilibrium constant,K,can be calculated from

Accepted Answer

A) E°. 
B) 
E)  
C) either E° or E. 
D) neither E° nor E. 
A) E°. 
B) 
E)  
C) either E° or E. 
D) neither E° nor E.

Which is most often used in the laboratory to measure pH?

Shown below is an electrochemical cell with anode a and cathode c.Both the anode and the cathode are inert electrodes.The liquid shown in compartment b of the cell is molten potassium chloride,KCl(l). -Determine the direction of electron flow and the direction of ion flow.

Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid,H₂CrO₄.What current is required to deposit chromium at a rate of 1.25 g/min?

Doubling all the coefficients in the equation for the cell reaction

The cell reaction for a dry cell battery is Zn(s)+ 2 MnO₂(s)+ 2 NH₄⁺(aq)→ 2 NH₃(aq)+ Mn₂O₃(s)+ Zn²⁺(aq)+ H₂O(l). The standard cell potential for this cell is 1.56 V.What is the standard free energy change for this cell?

Based on the half-reactions and their respective standard reduction potentials below,the strongest reducing agent is ,and the strongest oxidizing agent is . Ag⁺(aq)+ e^- → Ag(s)0.80 V 2 H⁺(aq)+ 2 e^- → H₂(g)0.00 V Cd²⁺(aq)+ 2 e^- → Cd(s)-0.40 V

A particular 12V battery is based on a reaction having a standard cell potential,E° = +1.92 V.What happens when the battery "dies"?

For a galvanic cell,the cathode has a sign and is the site of .

The chlor-alkali industry is based on the electrolysis of aqueous NaCl.What are the products of this electrolysis?

The following cell has a potential of 0.45 V at 25°C. Pt(s)∣ H₂(1 atm)|H⁺(? M)∣∣ Cl^-(1 M)∣ Hg₂Cl₂(s)|Hg(l) The standard half-cell potential for the half-reaction Hg₂Cl₂(s)+ 2 e^- → 2 Hg(l)+ 2 Cl^-(aq)is 0.28 V.What is the pH in the anode compartment?

-The cell reaction 2 Fe³⁺(aq)+ Zn(s)→ Zn²⁺(aq)+ 2 Fe²⁺(aq)occurs in the galvanic cell shown above.Which would be the most appropriate choices for the solid electrode in half-cell (A)and in half-cell (B)?

O₂(g)+ 4 H⁺(aq)+ 4 e^- → 2 H₂O(l)E° = +1.23 V Pb²⁺(aq)+ 2 e^- → Pb(s)E° = -0.13 V 2 H₂O(l)+ 2 e^-→ H₂(g)+ 2 OH^-(aq)E° = -0.83 V Based on the half-reactions above,electrolysis of an aqueous solution of Pb(NO₃)₂ is expected to produce.

Galvanized steel is steel coated with a layer of

Consider the galvanic cell shown below. -What is the balanced equation for the cell reaction?

Consider the following galvanic cell. -Identify the anode and cathode,and indicate the direction of Na⁺ ion and NO₃^- ion flow from the salt bridge.

A galvanic cell consists of one half-cell that contains Ag(s)and Ag⁺(aq),and one half-cell that contains Cu(s)and Cu²⁺(aq).What species are produced at the electrodes under standard conditions? Ag⁺(aq)+ e^- → Ag(s)E° = +0.80 V Cu²⁺(aq)+ 2 e^- → Cu(s)E° = +0.34 V

The equilibrium constant,K,can be calculated from

Chemistry: Matter and Measurement

Atoms, molecules, and Ions

Formulas, equations, and Moles

Reactions in Aqueous Solutions

Periodicity and the Atomic Structure of Atoms

Ionic Bonds and Some Main-Group Chemistry

Covalent Bonds and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids,solids,and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Hydrogen, oxygen, and Water

The Main-Group Elements

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

Nuclear Chemistry

Organic and Biological Chemistry

Filters

Exam 17: Electrochemistry

Which is most often used in the laboratory to measure pH?

Shown below is an electrochemical cell with anode a and cathode c.Both the anode and the cathode are inert electrodes.The liquid shown in compartment b of the cell is molten potassium chloride,KCl(l). -Determine the direction of electron flow and the direction of ion flow.

Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid,H2CrO4.What current is required to deposit chromium at a rate of 1.25 g/min?

Doubling all the coefficients in the equation for the cell reaction

The cell reaction for a dry cell battery is Zn(s)+ 2 MnO2(s)+ 2 NH4+(aq)→ 2 NH3(aq)+ Mn2O3(s)+ Zn2+(aq)+ H2O(l). The standard cell potential for this cell is 1.56 V.What is the standard free energy change for this cell?

Based on the half-reactions and their respective standard reduction potentials below,the strongest reducing agent is ________,and the strongest oxidizing agent is ________. Ag+(aq)+ e- → Ag(s)0.80 V 2 H+(aq)+ 2 e- → H2(g)0.00 V Cd2+(aq)+ 2 e- → Cd(s)-0.40 V

A particular 12V battery is based on a reaction having a standard cell potential,E° = +1.92 V.What happens when the battery "dies"?

For a galvanic cell,the cathode has a ________ sign and is the site of ________.

The chlor-alkali industry is based on the electrolysis of aqueous NaCl.What are the products of this electrolysis?

The following cell has a potential of 0.45 V at 25°C. Pt(s)∣ H2(1 atm)|H+(? M)∣∣ Cl-(1 M)∣ Hg2Cl2(s)|Hg(l) The standard half-cell potential for the half-reaction Hg2Cl2(s)+ 2 e- → 2 Hg(l)+ 2 Cl-(aq)is 0.28 V.What is the pH in the anode compartment?

-The cell reaction 2 Fe3+(aq)+ Zn(s)→ Zn2+(aq)+ 2 Fe2+(aq)occurs in the galvanic cell shown above.Which would be the most appropriate choices for the solid electrode in half-cell (A)and in half-cell (B)?

O2(g)+ 4 H+(aq)+ 4 e- → 2 H2O(l)E° = +1.23 V Pb2+(aq)+ 2 e- → Pb(s)E° = -0.13 V 2 H2O(l)+ 2 e- → H2(g)+ 2 OH-(aq)E° = -0.83 V Based on the half-reactions above,electrolysis of an aqueous solution of Pb(NO3)2 is expected to produce.

Galvanized steel is steel coated with a layer of

Consider the galvanic cell shown below. -What is the balanced equation for the cell reaction?

Consider the following galvanic cell. -Identify the anode and cathode,and indicate the direction of Na+ ion and NO3- ion flow from the salt bridge.

A galvanic cell consists of one half-cell that contains Ag(s)and Ag+(aq),and one half-cell that contains Cu(s)and Cu2+(aq).What species are produced at the electrodes under standard conditions? Ag+(aq)+ e- → Ag(s)E° = +0.80 V Cu2+(aq)+ 2 e- → Cu(s)E° = +0.34 V

The equilibrium constant,K,can be calculated from

Chemistry: Matter and Measurement

Atoms, molecules, and Ions

Formulas, equations, and Moles

Reactions in Aqueous Solutions

Periodicity and the Atomic Structure of Atoms

Ionic Bonds and Some Main-Group Chemistry

Covalent Bonds and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids,solids,and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Hydrogen, oxygen, and Water

The Main-Group Elements

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

Nuclear Chemistry

Organic and Biological Chemistry

Filters

Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid,H₂CrO₄.What current is required to deposit chromium at a rate of 1.25 g/min?

The cell reaction for a dry cell battery is Zn(s)+ 2 MnO₂(s)+ 2 NH₄⁺(aq)→ 2 NH₃(aq)+ Mn₂O₃(s)+ Zn²⁺(aq)+ H₂O(l). The standard cell potential for this cell is 1.56 V.What is the standard free energy change for this cell?

Based on the half-reactions and their respective standard reduction potentials below,the strongest reducing agent is ,and the strongest oxidizing agent is . Ag⁺(aq)+ e^- → Ag(s)0.80 V 2 H⁺(aq)+ 2 e^- → H₂(g)0.00 V Cd²⁺(aq)+ 2 e^- → Cd(s)-0.40 V

For a galvanic cell,the cathode has a sign and is the site of .

The following cell has a potential of 0.45 V at 25°C. Pt(s)∣ H₂(1 atm)|H⁺(? M)∣∣ Cl^-(1 M)∣ Hg₂Cl₂(s)|Hg(l) The standard half-cell potential for the half-reaction Hg₂Cl₂(s)+ 2 e^- → 2 Hg(l)+ 2 Cl^-(aq)is 0.28 V.What is the pH in the anode compartment?

-The cell reaction 2 Fe³⁺(aq)+ Zn(s)→ Zn²⁺(aq)+ 2 Fe²⁺(aq)occurs in the galvanic cell shown above.Which would be the most appropriate choices for the solid electrode in half-cell (A)and in half-cell (B)?

O₂(g)+ 4 H⁺(aq)+ 4 e^- → 2 H₂O(l)E° = +1.23 V Pb²⁺(aq)+ 2 e^- → Pb(s)E° = -0.13 V 2 H₂O(l)+ 2 e^-→ H₂(g)+ 2 OH^-(aq)E° = -0.83 V Based on the half-reactions above,electrolysis of an aqueous solution of Pb(NO₃)₂ is expected to produce.

Consider the following galvanic cell. -Identify the anode and cathode,and indicate the direction of Na⁺ ion and NO₃^- ion flow from the salt bridge.

A galvanic cell consists of one half-cell that contains Ag(s)and Ag⁺(aq),and one half-cell that contains Cu(s)and Cu²⁺(aq).What species are produced at the electrodes under standard conditions? Ag⁺(aq)+ e^- → Ag(s)E° = +0.80 V Cu²⁺(aq)+ 2 e^- → Cu(s)E° = +0.34 V