Question 1

Calculate the equilibrium constant,K,at 25°C for the galvanic cell reaction shown below:

Accepted Answer

A) 3)2 × 10-63 
B) 3)2 × 10-13 
C) 3)2 × 1012 
D) 3)2 × 1062 
A) 3)2 × 10-63 
B) 3)2 × 10-13 
C) 3)2 × 1012 
D) 3)2 × 1062

Question 2

What is least easily oxidized?

Accepted Answer

A) Al 
B) Fe 
C) Mg 
D) Zn 
A) Al 
B) Fe 
C) Mg 
D) Zn

Question 3

For a particular cell based on the reaction:
3 AgCl(s)+ Al(s)→ 3 Ag(s)+ Al3+(aq)+ 3 Cl-(aq)
E = +1.750 V and E° = +1.884 V at 25°C.
What is the value of the equilibrium constant,K,at 25°C for the reaction?

Accepted Answer

A) 3)6 × 1029 
B) 6)7 × 1031 
C) 4)8 × 1088 
D) 3)0 × 1095 
A) 3)6 × 1029 
B) 6)7 × 1031 
C) 4)8 × 1088 
D) 3)0 × 1095

Question 4

-For the galvanic cell shown above,in what direction should the anions and cations in half-cell A move?

Accepted Answer

A) The anions tend to move to the solid electrode and the cations into the salt bridge. 
B) The anions tend to move into the salt bridge and the cations toward the solid electrode. 
C) The anions tend to move toward the solid electrode and the cations should not move. 
D) The cations tend to move toward the solid electrode and the anions should not move. 
A) The anions tend to move to the solid electrode and the cations into the salt bridge. 
B) The anions tend to move into the salt bridge and the cations toward the solid electrode. 
C) The anions tend to move toward the solid electrode and the cations should not move. 
D) The cations tend to move toward the solid electrode and the anions should not move.

Question 5

-Use Table 17.1 to determine which of the following is the best oxidizing agent.

Accepted Answer

A) Fe3+ 
B) I2 
C) MnO4- 
D) Pb2+ 
A) Fe3+ 
B) I2 
C) MnO4- 
D) Pb2+

Question 6

The standard potential for the following galvanic cell is +0.90 V:
3 Cu2+(aq)+ 2 Ga(s)⇌ 3 Cu(s)+ 2 Ga3+(aq)
Given that the standard reduction potential for the Cu2+/Cu half-cell is +0.34 V,what is the standard reduction potential for the Ga3+/Ga half-cell?

Accepted Answer

A) -1.34 V 
B) -0.56 V 
C) +0.56 V 
D) +1.36 V 
A) -1.34 V 
B) -0.56 V 
C) +0.56 V 
D) +1.36 V

Question 7

A salt bridge is used to

Accepted Answer

A) provide reactants in a fuel cell. 
B) determine the direction of the cell reaction. 
C) control whether the cell is electrolytic or galvanic. 
D) allow the ion flow necessary for cell neutrality. 
A) provide reactants in a fuel cell. 
B) determine the direction of the cell reaction. 
C) control whether the cell is electrolytic or galvanic. 
D) allow the ion flow necessary for cell neutrality.

Question 8

What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below?
Al(s)∣ Al3+(aq)∣∣ Ni2+(aq)∣ Ni(s)

Accepted Answer

A) 2 Al(s)+ 3 Ni2+(aq)→ 2 Al3+(aq)+ 3 Ni(s) 
B) 3 Al(s)+ 2 Ni2+(aq)→ 3 Al3+(aq)+ 2 Ni(s) 
C) 2 Ni(s)+ 3 Al3+(aq)→ 2 Ni2+(aq)+ 3 Al(s) 
D) 3 Ni(s)+ 2 Al3+(aq)→ 3 Ni2+(aq)+ 2 Al(s) 
A) 2 Al(s)+ 3 Ni2+(aq)→ 2 Al3+(aq)+ 3 Ni(s) 
B) 3 Al(s)+ 2 Ni2+(aq)→ 3 Al3+(aq)+ 2 Ni(s) 
C) 2 Ni(s)+ 3 Al3+(aq)→ 2 Ni2+(aq)+ 3 Al(s) 
D) 3 Ni(s)+ 2 Al3+(aq)→ 3 Ni2+(aq)+ 2 Al(s)

Question 9

Given that Cl2(g)+ 2 e- ? 2 Cl-(aq)is the reduction half-reaction for the overall reaction
2 Ag(s)+ Cl2 (g) $\rarr$ 2 AgCl(s),what is the oxidation half reaction?

Accepted Answer

A) Ag(s)? Ag+(aq)+ e- 
B) Ag(s)+ Cl-(aq)? AgCl(s)+ e- 
C) Ag(s)+ Cl2(g)+ e- ? AgCl(s)+ Cl-(aq) 
D) 2 Cl-(aq)? Cl2(g)+ 2 e- 
A) Ag(s)? Ag+(aq)+ e- 
B) Ag(s)+ Cl-(aq)? AgCl(s)+ e- 
C) Ag(s)+ Cl2(g)+ e- ? AgCl(s)+ Cl-(aq) 
D) 2 Cl-(aq)? Cl2(g)+ 2 e-

Question 10

-Is the cell shown above a galvanic or an electrolytic cell? What is the direction of ion flow?

Accepted Answer

A) Electrolytic cell;Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y. 
B) Electrolytic cell;Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x. 
C) Galvanic cell;Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y. 
D) Galvanic cell;Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x. 
A) Electrolytic cell;Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y. 
B) Electrolytic cell;Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x. 
C) Galvanic cell;Cu2+ ions flow toward electrode x and SO42- ions flow toward electrode y. 
D) Galvanic cell;Cu2+ ions flow toward electrode y and SO42- ions flow toward electrode x.

Question 11

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 5.00 moles of copper metal?

Accepted Answer

A) 0)187 hours 
B) 0)373 hours 
C) 2)68 hours 
D) 5)36 hours 
A) 0)187 hours 
B) 0)373 hours 
C) 2)68 hours 
D) 5)36 hours

Question 12

Consider the galvanic cell,Pb(s)| Pb2+(aq)|| Cu2+(aq)| Cu(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

Accepted Answer

A) increase the [Pb2+] concentration 
B) increase the [Cu2+] concentration 
C) increase the mass of Pb(s) 
D) decrease the mass of Pb(s) 
A) increase the [Pb2+] concentration 
B) increase the [Cu2+] concentration 
C) increase the mass of Pb(s) 
D) decrease the mass of Pb(s)

Question 13

Consider the galvanic cell,Zn(s)∣ Zn2+(aq)∣∣ Pb2+(aq)∣ Pb(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

Accepted Answer

A) increase the [ Zn2+] concentration 
B) increase the [ Pb2+] concentration 
C) increase the mass of Zn(s) 
D) decrease the mass of Zn(s) 
A) increase the [ Zn2+] concentration 
B) increase the [ Pb2+] concentration 
C) increase the mass of Zn(s) 
D) decrease the mass of Zn(s)

Question 14

In a galvanic cell,the half-reaction MnO4-(aq)+ 8 H+(aq)+ 5 e- → Mn2+(aq)+ 4 H2O(l)is

Accepted Answer

A) an oxidation half-reaction and occurs at the anode. 
B) an oxidation half-reaction and occurs at the cathode. 
C) a reduction half-reaction and occurs at the anode. 
D) a reduction half-reaction and occurs at the cathode. 
A) an oxidation half-reaction and occurs at the anode. 
B) an oxidation half-reaction and occurs at the cathode. 
C) a reduction half-reaction and occurs at the anode. 
D) a reduction half-reaction and occurs at the cathode.

Question 15

Calculate the cell potential at 25°C for the cell
Fe(s)∣ (Fe2+(0.100 M)∣∣ Pd2+(1.0 × 10-5 M)∣ Pd(s)
Given that the standard reduction potential for Fe2+/Fe is -0.45 V and for Pd2+/Pd is +0.95 V.

Accepted Answer

A) +1.16 V 
B) +1.28 V 
C) +1.52 V 
D) +1.68 V 
A) +1.16 V 
B) +1.28 V 
C) +1.52 V 
D) +1.68 V

Question 16

Consider the following galvanic cell.  
-What is the quantitative change in the cell voltage on increasing the ion concentration in the cathode compartment by a factor of 10?

Accepted Answer

A) +0.06 V 
B) +0.03 V 
C) -0.03 V 
D) -0.06 V 
A) +0.06 V 
B) +0.03 V 
C) -0.03 V 
D) -0.06 V

Question 17

Consider the following standard reduction potentials,
Al3+(aq)+ 3 e- → Al(s)E° = -1.66 V
I2(s)+ 2 e- → 2 I-(aq)E° = +0.54 V
Under standard conditions,

Accepted Answer

A) Al3+(aq)is a stronger oxidizing agent than I2(s),and I-(aq)is a stronger reducing agent than Al(s). 
B) I2(s)is a stronger oxidizing agent than Al3+(aq),and Al(s)is a stronger reducing agent than I-(aq). 
C) Al(s)is a stronger oxidizing agent than I-(aq),and Al3+(aq)is a stronger reducing agent than I2(s). 
D) I-(aq)is a stronger oxidizing agent than Al(s),and I2(s)is a stronger reducing agent than Al3+(aq). 
A) Al3+(aq)is a stronger oxidizing agent than I2(s),and I-(aq)is a stronger reducing agent than Al(s). 
B) I2(s)is a stronger oxidizing agent than Al3+(aq),and Al(s)is a stronger reducing agent than I-(aq). 
C) Al(s)is a stronger oxidizing agent than I-(aq),and Al3+(aq)is a stronger reducing agent than I2(s). 
D) I-(aq)is a stronger oxidizing agent than Al(s),and I2(s)is a stronger reducing agent than Al3+(aq).

Question 18

Using the following standard reduction potentials,
Fe3+(aq)+ e- → Fe2+(aq)E° = +0.77 V
Ni2+(aq)+ 2 e- →Ni(s)E° = -0.26 V
Calculate the standard cell potential for the cell reaction given below,and determine whether or not this reaction is spontaneous under standard conditions.
Ni2+(aq)+ 2 Fe2+(aq)→ 2 Fe3+(aq)+ Ni(s)

Accepted Answer

A) E° = - 1.03 V,nonspontaneous 
B) E° = - 1.03 V,spontaneous 
C) E° = + 1.03,nonspontaneous 
D) E° = + 1.03,spontaneous 
A) E° = - 1.03 V,nonspontaneous 
B) E° = - 1.03 V,spontaneous 
C) E° = + 1.03,nonspontaneous 
D) E° = + 1.03,spontaneous

Question 19

O2(g)+ 4 H+(aq)+ 4 e-→ 2 H2O(l)E° = +1.23 V
I2(s)+ 2 e- → 2 I-(aq)E° = +0.54 V
2 H2O(l)+ 2 e- → H2(g)+ 2 OH-(aq)E° = -0.83 V
Mg2+(aq)+ 2 e- → Mg(s)E° = -2.37 V
Based on the data above,electrolysis of an aqueous solution of MgI2,with inert electrodes,is expected to produce

Accepted Answer

A) Mg at the cathode and I2 at the anode. 
B) H2 at the cathode and I2 at the anode. 
C) Mg at the cathode and O2 at the anode. 
D) H2 at the cathode and O2 at the anode. 
A) Mg at the cathode and I2 at the anode. 
B) H2 at the cathode and I2 at the anode. 
C) Mg at the cathode and O2 at the anode. 
D) H2 at the cathode and O2 at the anode.

Question 20

Which statement concerning overvoltage is false?

Accepted Answer

A) Overvoltage is the additional voltage above the calculated voltage required to bring about electrolysis. 
B) Overvoltage is often due to a high activation energy for the reaction at one electrode. 
C) Overvoltage is small for half-reactions involving the formation of O2(g)or H2(g). 
D) Overvoltage must be experimentally determined. 
A) Overvoltage is the additional voltage above the calculated voltage required to bring about electrolysis. 
B) Overvoltage is often due to a high activation energy for the reaction at one electrode. 
C) Overvoltage is small for half-reactions involving the formation of O2(g)or H2(g). 
D) Overvoltage must be experimentally determined.

Exam 17: Electrochemistry

Calculate the equilibrium constant,K,at 25°C for the galvanic cell reaction shown below:

What is least easily oxidized?

For a particular cell based on the reaction: 3 AgCl(s)+ Al(s)→ 3 Ag(s)+ Al3+(aq)+ 3 Cl-(aq) E = +1.750 V and E° = +1.884 V at 25°C. What is the value of the equilibrium constant,K,at 25°C for the reaction?

-For the galvanic cell shown above,in what direction should the anions and cations in half-cell A move?

-Use Table 17.1 to determine which of the following is the best oxidizing agent.

The standard potential for the following galvanic cell is +0.90 V: 3 Cu2+(aq)+ 2 Ga(s)⇌ 3 Cu(s)+ 2 Ga3+(aq) Given that the standard reduction potential for the Cu2+/Cu half-cell is +0.34 V,what is the standard reduction potential for the Ga3+/Ga half-cell?

A salt bridge is used to

What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below? Al(s)∣ Al3+(aq)∣∣ Ni2+(aq)∣ Ni(s)

Given that Cl2(g)+ 2 e- ? 2 Cl-(aq)is the reduction half-reaction for the overall reaction 2 Ag(s)+ Cl2 (g) →\rarr→ 2 AgCl(s),what is the oxidation half reaction?

-Is the cell shown above a galvanic or an electrolytic cell? What is the direction of ion flow?

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 5.00 moles of copper metal?

Consider the galvanic cell,Pb(s)| Pb2+(aq)|| Cu2+(aq)| Cu(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

Consider the galvanic cell,Zn(s)∣ Zn2+(aq)∣∣ Pb2+(aq)∣ Pb(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

In a galvanic cell,the half-reaction MnO4-(aq)+ 8 H+(aq)+ 5 e- → Mn2+(aq)+ 4 H2O(l)is

Calculate the cell potential at 25°C for the cell Fe(s)∣ (Fe2+(0.100 M)∣∣ Pd2+(1.0 × 10-5 M)∣ Pd(s) Given that the standard reduction potential for Fe2+/Fe is -0.45 V and for Pd2+/Pd is +0.95 V.

Consider the following galvanic cell. -What is the quantitative change in the cell voltage on increasing the ion concentration in the cathode compartment by a factor of 10?

Consider the following standard reduction potentials, Al3+(aq)+ 3 e- → Al(s)E° = -1.66 V I2(s)+ 2 e- → 2 I-(aq)E° = +0.54 V Under standard conditions,

O2(g)+ 4 H+(aq)+ 4 e-→ 2 H2O(l)E° = +1.23 V I2(s)+ 2 e- → 2 I-(aq)E° = +0.54 V 2 H2O(l)+ 2 e- → H2(g)+ 2 OH-(aq)E° = -0.83 V Mg2+(aq)+ 2 e- → Mg(s)E° = -2.37 V Based on the data above,electrolysis of an aqueous solution of MgI2,with inert electrodes,is expected to produce

Which statement concerning overvoltage is false?

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For a particular cell based on the reaction: 3 AgCl(s)+ Al(s)→ 3 Ag(s)+ Al³⁺(aq)+ 3 Cl^-(aq) E = +1.750 V and E° = +1.884 V at 25°C. What is the value of the equilibrium constant,K,at 25°C for the reaction?

The standard potential for the following galvanic cell is +0.90 V: 3 Cu²⁺(aq)+ 2 Ga(s)⇌ 3 Cu(s)+ 2 Ga³⁺(aq) Given that the standard reduction potential for the Cu²⁺/Cu half-cell is +0.34 V,what is the standard reduction potential for the Ga³⁺/Ga half-cell?

What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below? Al(s)∣ Al³⁺(aq)∣∣ Ni²⁺(aq)∣ Ni(s)

Given that Cl₂(g)+ 2 e^- ? 2 Cl^-(aq)is the reduction half-reaction for the overall reaction 2 Ag(s)+ Cl₂ (g) $\rarr$ 2 AgCl(s),what is the oxidation half reaction?

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu²⁺ ions to produce 5.00 moles of copper metal?

Consider the galvanic cell,Pb(s)| Pb2+(aq)|| Cu²⁺(aq)| Cu(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

Consider the galvanic cell,Zn(s)∣ Zn²⁺(aq)∣∣ Pb²⁺(aq)∣ Pb(s).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

In a galvanic cell,the half-reaction MnO₄^-(aq)+ 8 H⁺(aq)+ 5 e^- → Mn²⁺(aq)+ 4 H₂O(l)is

Calculate the cell potential at 25°C for the cell Fe(s)∣ (Fe²⁺(0.100 M)∣∣ Pd²⁺(1.0 × 10^-5 M)∣ Pd(s) Given that the standard reduction potential for Fe²⁺/Fe is -0.45 V and for Pd²⁺/Pd is +0.95 V.

Consider the following standard reduction potentials, Al³⁺(aq)+ 3 e^- → Al(s)E° = -1.66 V I₂(s)+ 2 e^- → 2 I^-(aq)E° = +0.54 V Under standard conditions,