Question 1

Which is incorrect?

Accepted Answer

A) At equilibrium,Ecell = 0. B) E > 0 for a spontaneous process. C) E = 0 for a spontaneous process. D) ΔG < 0 for a spontaneous process. E) ΔG = 0 at equilibrium. A) At equilibrium,Ecell = 0. B) E > 0 for a spontaneous process. C) E = 0 for a spontaneous process. D) ΔG < 0 for a spontaneous process. E) ΔG = 0 at equilibrium.

Question 2

What is the standard free-energy change for the following reaction at 25°C? (F = 96,500 C • mol-1) 2Al(s)+ 3Sn4+(aq,1 M)→ 2Al3+(aq,1 M)+ 3Sn2+(aq,1 M)
Half-Reaction Eo (V)
Al3+(aq)+ 3e- → Al(s)-1.66
Sn4+(aq)+ 2e- →Sn2+(aq)+0.13

Accepted Answer

A) -1.79 kJ/mol 
B) 1.79 kJ/mol 
C) -1.04 × 103 kJ/mol 
D) -3.45 × 102 kJ/mol 
E) 5.18 × 102 kJ/mol 
A) -1.79 kJ/mol 
B) 1.79 kJ/mol 
C) -1.04 × 103 kJ/mol 
D) -3.45 × 102 kJ/mol 
E) 5.18 × 102 kJ/mol

Question 3

Consider the following balanced redox reaction. 3CuO(s)+ 2NH3(aq)→ N2(g)+ 3H2O(l)+ 3Cu(s)
Which of the following statements is true?

Accepted Answer

A) CuO(s)is the oxidizing agent and copper is reduced. 
B) CuO(s)is the oxidizing agent and copper is oxidized. 
C) CuO(s)is the reducing agent and copper is oxidized. 
D) CuO(s)is the reducing agent and copper is reduced. 
E) CuO(s)is the oxidizing agent and N2(g)is the reducing agent. 
A) CuO(s)is the oxidizing agent and copper is reduced. 
B) CuO(s)is the oxidizing agent and copper is oxidized. 
C) CuO(s)is the reducing agent and copper is oxidized. 
D) CuO(s)is the reducing agent and copper is reduced. 
E) CuO(s)is the oxidizing agent and N2(g)is the reducing agent.

Question 4

In a fuel cell,an external source of electrical power is used to drive a nonspontaneous reaction in which a fuel is produced.

Accepted Answer

A) True 
 B)False

Question 5

What product forms at the anode during the electrolysis of molten NaBr?

Accepted Answer

A) Na+(l) 
B) Na(l) 
C) Br-(l) 
D) Br3-(l) 
E) Br2(g) 
A) Na+(l) 
B) Na(l) 
C) Br-(l) 
D) Br3-(l) 
E) Br2(g)

Question 6

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient for nitrogen dioxide? I2(s)+ HNO3(aq)→ HIO3(aq)+ NO2(g)+ H2O(l)

Accepted Answer

A) 1 
B) 2 
C) 4 
D) 5 
E) 10 
A) 1 
B) 2 
C) 4 
D) 5 
E) 10

Question 7

What is ΔG° at 200°C for the following reaction? (F = 96,500 C • mol-1) 2Na(l)+ FeCl2(s)   2NaCl(s)+ Fe(s)E°cell = 2.35 V

Accepted Answer

A) 454 kJ/mol 
B) -454 kJ/mol 
C) 907 kJ/mol 
D) -907 kJ/mol 
E) 227 kJ/mol 
A) 454 kJ/mol 
B) -454 kJ/mol 
C) 907 kJ/mol 
D) -907 kJ/mol 
E) 227 kJ/mol

Question 8

Which is the half-reaction at the cathode in a lead storage battery?

Accepted Answer

A) Pb(s)+ PbO2(s)+ 4H+(aq)+ 2SO42-(aq)→ 2PbSO4(s)+ 2H2O(l) 
B) PbO2(s)+ 4H+(aq)+ 2SO42-(aq)+ 2e- → PbSO4(s)+ 2H2O(l) 
C) Pb(s)+ SO42-(aq)→ PbSO4(s)+ 2e- 
D) Pb(s)→ Pb(s)+ 2e- 
E) H2(g)→ 2H+(aq)+ 2e- 
A) Pb(s)+ PbO2(s)+ 4H+(aq)+ 2SO42-(aq)→ 2PbSO4(s)+ 2H2O(l) 
B) PbO2(s)+ 4H+(aq)+ 2SO42-(aq)+ 2e- → PbSO4(s)+ 2H2O(l) 
C) Pb(s)+ SO42-(aq)→ PbSO4(s)+ 2e- 
D) Pb(s)→ Pb(s)+ 2e- 
E) H2(g)→ 2H+(aq)+ 2e-

Question 9

What is E°cell for the following reaction? 2Fe2+(aq)+ Cd2+(aq)→ 2Fe3+(aq)+ Cd(s)
Fe3+(aq)+ e- →Fe2+ (aq)E° = 0.77 V
Cd2+(aq)+ 2e- → Cd(s)E° = -0.40 V

Accepted Answer

A) -0.37 V 
B) 0.37 V 
C) -1.17 V 
D) 1.17 V 
E) None of these choices is correct 
A) -0.37 V 
B) 0.37 V 
C) -1.17 V 
D) 1.17 V 
E) None of these choices is correct

Question 10

If ΔG° of the following reaction is -110 kJ/mol,what is E°cell? (F = 96,500 C • mol-1) A3+(aq)+ 3B(s)→ A(s)+ 3B+(aq)

Accepted Answer

A) +0.38 V 
B) -0.09 V 
C) -0.38 V 
D) +0.00038 V 
E) +0.09 V 
A) +0.38 V 
B) -0.09 V 
C) -0.38 V 
D) +0.00038 V 
E) +0.09 V

Question 11

Consider the reaction in the lead-acid cell Pb(s)+ PbO2(s)+ 2H2SO4(aq)→ 2PbSO4(aq)+ 2H2O(l)
For which E°cell = 2.04 V at 298 K.ΔG° for this reaction is

Accepted Answer

A) -3.94 × 105 kJ/mol. 
B) -3.94 × 102 kJ/mol. 
C) -1.97 × 105 kJ/mol. 
D) -7.87 × 102 kJ/mol. 
E) -7.87 × 105 kJ/mol. 
A) -3.94 × 105 kJ/mol. 
B) -3.94 × 102 kJ/mol. 
C) -1.97 × 105 kJ/mol. 
D) -7.87 × 102 kJ/mol. 
E) -7.87 × 105 kJ/mol.

Question 12

What is ΔG° for the following reaction? (F = 96,500 C • mol-1) I2(s)+ 2Br-(aq)→ 2I-(aq)+ Br2(l)
Given:
I2(s) (aq)+ 2e- → 2I-(aq)E°= 0.53 V
Br2(l)+ 2e- → 2Br-(aq)E° = 1.07 V

Accepted Answer

A) +104 kJ/mol 
B) -104 kJ/mol 
C) +309 kJ/mol 
D) +52 kJ/mol 
E) -52 kJ/mol 
A) +104 kJ/mol 
B) -104 kJ/mol 
C) +309 kJ/mol 
D) +52 kJ/mol 
E) -52 kJ/mol

Question 13

A voltaic cell consists of a Mn/Mn2+ electrode (E° = -1.18 V)and a Fe/Fe2+ electrode (E° = -0.44 V).Calculate [Fe2+] if [Mn2+] = 0.050 M and Ecell = 0.78 V at 25°C.

Accepted Answer

A) 0.040 M 
B) 0.24 M 
C) 1.1 M 
D) 1.8 M 
E) None of these choices is correct. 
A) 0.040 M 
B) 0.24 M 
C) 1.1 M 
D) 1.8 M 
E) None of these choices is correct.

Question 14

Which of the following is correct?

Accepted Answer

A) total charge = volts/coulombs 
B) electrical energy = volts × coulombs 
C) Faraday = coulombs/joules 
D) coulombs = joules × volts 
E) electrical work = Faraday's constant/Ecell 
A) total charge = volts/coulombs 
B) electrical energy = volts × coulombs 
C) Faraday = coulombs/joules 
D) coulombs = joules × volts 
E) electrical work = Faraday's constant/Ecell

Question 15

E > 0 and ΔG < 0 for a spontaneous process.

Accepted Answer

A) True 
 B)False

Question 16

___________ - _________ fuel cells provide electrical power and drinking water for space flights.

Accepted Answer

The answer of ___________ - _________ fuel cells provide electrical...

Question 17

What is meant by SHE?

Accepted Answer

A) Shared half electrodes 
B) Shifting half of the electricity 
C) Standard hydrogen electrode 
D) Small helium electrode 
E) Standard Hg electrode 
A) Shared half electrodes 
B) Shifting half of the electricity 
C) Standard hydrogen electrode 
D) Small helium electrode 
E) Standard Hg electrode

Question 18

______________ is the process that uses electrical energy to drive a nonspontaneous chemical reaction.

Accepted Answer

The answer of ______________ is the process that uses electrical...

Question 19

If the following electrochemical cell is constructed,what voltage will be measured on the voltmeter?   Half-Reaction E° (V) Zn2+(aq)+ 2e- →Zn(s)-0.76
Ag+(aq)+ e- → Ag(s)+0.80

Accepted Answer

A) 2.36 V 
B) 1.56 V 
C) 0.04 V 
D) -0.04 V 
E) -2.36 V 
A) 2.36 V 
B) 1.56 V 
C) 0.04 V 
D) -0.04 V 
E) -2.36 V

Question 20

Which of the following elements can be isolated by electrolysis of the aqueous salt shown?

Accepted Answer

A) Phosphorus from K3PO4(aq) 
B) Sodium from NaBr(aq) 
C) Aluminum from AlCl3(aq) 
D) Fluorine from KF(aq) 
E) Iodine from NaI(aq) 
A) Phosphorus from K3PO4(aq) 
B) Sodium from NaBr(aq) 
C) Aluminum from AlCl3(aq) 
D) Fluorine from KF(aq) 
E) Iodine from NaI(aq)

Exam 19: Electrochemistry

Which is incorrect?

What is the standard free-energy change for the following reaction at 25°C? (F = 96,500 C • mol-1) 2Al(s)+ 3Sn4+(aq,1 M)→ 2Al3+(aq,1 M)+ 3Sn2+(aq,1 M) Half-Reaction Eo (V) Al3+(aq)+ 3e- → Al(s)-1.66 Sn4+(aq)+ 2e- →Sn2+(aq)+0.13

Consider the following balanced redox reaction. 3CuO(s)+ 2NH3(aq)→ N2(g)+ 3H2O(l)+ 3Cu(s) Which of the following statements is true?

In a fuel cell,an external source of electrical power is used to drive a nonspontaneous reaction in which a fuel is produced.

What product forms at the anode during the electrolysis of molten NaBr?

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient for nitrogen dioxide? I2(s)+ HNO3(aq)→ HIO3(aq)+ NO2(g)+ H2O(l)

What is ΔG° at 200°C for the following reaction? (F = 96,500 C • mol-1) 2Na(l)+ FeCl2(s) 2NaCl(s)+ Fe(s)E°cell = 2.35 V

Which is the half-reaction at the cathode in a lead storage battery?

What is E°cell for the following reaction? 2Fe2+(aq)+ Cd2+(aq)→ 2Fe3+(aq)+ Cd(s) Fe3+(aq)+ e- →Fe2+ (aq)E° = 0.77 V Cd2+(aq)+ 2e- → Cd(s)E° = -0.40 V

If ΔG° of the following reaction is -110 kJ/mol,what is E°cell? (F = 96,500 C • mol-1) A3+(aq)+ 3B(s)→ A(s)+ 3B+(aq)

Consider the reaction in the lead-acid cell Pb(s)+ PbO2(s)+ 2H2SO4(aq)→ 2PbSO4(aq)+ 2H2O(l) For which E°cell = 2.04 V at 298 K.ΔG° for this reaction is

What is ΔG° for the following reaction? (F = 96,500 C • mol-1) I2(s)+ 2Br-(aq)→ 2I-(aq)+ Br2(l) Given: I2(s) (aq)+ 2e- → 2I-(aq)E°= 0.53 V Br2(l)+ 2e- → 2Br-(aq)E° = 1.07 V

A voltaic cell consists of a Mn/Mn2+ electrode (E° = -1.18 V)and a Fe/Fe2+ electrode (E° = -0.44 V).Calculate [Fe2+] if [Mn2+] = 0.050 M and Ecell = 0.78 V at 25°C.

Which of the following is correct?

E > 0 and ΔG < 0 for a spontaneous process.

___________ - _________ fuel cells provide electrical power and drinking water for space flights.

What is meant by SHE?

______________ is the process that uses electrical energy to drive a nonspontaneous chemical reaction.

If the following electrochemical cell is constructed,what voltage will be measured on the voltmeter? Half-Reaction E° (V) Zn2+(aq)+ 2e- →Zn(s)-0.76 Ag+(aq)+ e- → Ag(s)+0.80

Which of the following elements can be isolated by electrolysis of the aqueous salt shown?

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Filters

What is the standard free-energy change for the following reaction at 25°C? (F = 96,500 C • mol^-1) 2Al(s)+ 3Sn⁴⁺(aq,1 M)→ 2Al³⁺(aq,1 M)+ 3Sn²⁺(aq,1 M) Half-Reaction Eo (V) Al³⁺(aq)+ 3e^- → Al(s)-1.66 Sn⁴⁺(aq)+ 2e^- →Sn²⁺(aq)+0.13

Consider the following balanced redox reaction. 3CuO(s)+ 2NH₃(aq)→ N₂(g)+ 3H₂O(l)+ 3Cu(s) Which of the following statements is true?

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient for nitrogen dioxide? I₂(s)+ HNO₃(aq)→ HIO₃(aq)+ NO₂(g)+ H₂O(l)

What is ΔG° at 200°C for the following reaction? (F = 96,500 C • mol^-1) 2Na(l)+ FeCl₂(s) 2NaCl(s)+ Fe(s)E°_cell = 2.35 V

What is E°_cell for the following reaction? 2Fe²⁺(aq)+ Cd²⁺(aq)→ 2Fe³⁺(aq)+ Cd(s) Fe³⁺(aq)+ e^- →Fe²⁺ (aq)E° = 0.77 V Cd²⁺(aq)+ 2e^- → Cd(s)E° = -0.40 V

If ΔG° of the following reaction is -110 kJ/mol,what is E°_cell? (F = 96,500 C • mol^-1) A³⁺(aq)+ 3B(s)→ A(s)+ 3B⁺(aq)

Consider the reaction in the lead-acid cell Pb(s)+ PbO₂(s)+ 2H₂SO₄(aq)→ 2PbSO₄(aq)+ 2H₂O(l) For which E°_cell = 2.04 V at 298 K.ΔG° for this reaction is

What is ΔG° for the following reaction? (F = 96,500 C • mol^-1) I₂(s)+ 2Br^-(aq)→ 2I^-(aq)+ Br₂(l) Given: I₂(s) (aq)+ 2e^- → 2I^-(aq)E°= 0.53 V Br₂(l)+ 2e^- → 2Br^-(aq)E° = 1.07 V

A voltaic cell consists of a Mn/Mn²⁺ electrode (E° = -1.18 V)and a Fe/Fe²⁺ electrode (E° = -0.44 V).Calculate [Fe²⁺] if [Mn²⁺] = 0.050 M and E_cell = 0.78 V at 25°C.

___ - _ fuel cells provide electrical power and drinking water for space flights.

If the following electrochemical cell is constructed,what voltage will be measured on the voltmeter? Half-Reaction E° (V) Zn²⁺(aq)+ 2e^- →Zn(s)-0.76 Ag⁺(aq)+ e^- → Ag(s)+0.80