Question 1

Which is not true for standard electrode potentials?

Accepted Answer

A) Cell constituents are in their standard states. 
B) E° for oxidation is the negative of E° for reduction. 
C) The half-reactions are written as reductions. 
D) The potential for the standard hydrogen electrode is chosen to be +1.00 V. 
A) Cell constituents are in their standard states. 
B) E° for oxidation is the negative of E° for reduction. 
C) The half-reactions are written as reductions. 
D) The potential for the standard hydrogen electrode is chosen to be +1.00 V. D

Question 2

For the hypothetical reaction A + Bx → Ax + B,E° = 1.19 V = and ΔG° = -115 kJ.For this reaction the value of x = .

Accepted Answer

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

Question 3

Consider the galvanic cell shown below.  
-Identify the anode and cathode,and indicate the direction of ion flow to and from each electrode.

Accepted Answer

A) Al is the anode and Co is the cathode;Al3+ ions flow to the anode and Co2+ ions flow from the cathode. 
B) Al is the anode and Co is the cathode;Co2+ ions flow to the cathode and Al3+ ions flow from the anode. 
C) Co is the anode and Al is the cathode;Al3+ ions flow to the cathode and Co2+ ions flow from the anode. 
D) Co is the anode and Al is the cathode;Co2+ ions flow to the anode and Al3+ ions flow from the cathode. 
A) Al is the anode and Co is the cathode;Al3+ ions flow to the anode and Co2+ ions flow from the cathode. 
B) Al is the anode and Co is the cathode;Co2+ ions flow to the cathode and Al3+ ions flow from the anode. 
C) Co is the anode and Al is the cathode;Al3+ ions flow to the cathode and Co2+ ions flow from the anode. 
D) Co is the anode and Al is the cathode;Co2+ ions flow to the anode and Al3+ ions flow from the cathode. B

Question 4

Given the half-cell potentials below,calculate the cell potential. Ag+(aq)+ e- → Ag(s)0.80 V
Cu2+(aq)+ 2 e- → Cu(s)0.34 V

Accepted Answer

A) 0.46 V 
B) 1.14 V 
C) 1.26 V 
D) 1.94 V 
A) 0.46 V 
B) 1.14 V 
C) 1.26 V 
D) 1.94 V

Question 5

Galvanized steel is steel coated with a layer of

Accepted Answer

A) Fe2O3. 
B) Ag. 
C) Pb. 
D) Zn. 
A) Fe2O3. 
B) Ag. 
C) Pb. 
D) Zn.

Question 6

-According to Table 17.1,which will reduce water but not Mg2+?

Accepted Answer

A) Al3+(aq) 
B) Al(s) 
C) Na+(aq) 
D) Na(s) 
A) Al3+(aq) 
B) Al(s) 
C) Na+(aq) 
D) Na(s)

Question 7

Calculate the cell potential E at 25°C for the reaction 2 Al(s)+ 3 Fe2+(aq)→ 2 Al3+(aq)+ 3 Fe(s)
Given that [Fe2+] = 0.020 M,[Al3+] = 0.10 M,and the standard reduction potential is -1.66 V for Al3+/Al and -0.45 V for Fe2+/Fe.

Accepted Answer

A) +1.03 V 
B) +1.17 V 
C) +1.18 V 
D) +1.20 V 
A) +1.03 V 
B) +1.17 V 
C) +1.18 V 
D) +1.20 V

Question 8

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 3.50 moles of copper metal?

Accepted Answer

A) 0.267 hours 
B) 0.533 hours 
C) 1.88 hours 
D) 3.75 hours 
A) 0.267 hours 
B) 0.533 hours 
C) 1.88 hours 
D) 3.75 hours

Question 9

For the galvanic cell reaction,expressed below using shorthand notation,what half-reaction occurs at the anode? Fe(s)∣ Fe2+(aq)∣∣ Cd2+(aq)∣Cd(s)

Accepted Answer

A) Fe(s)→ Fe2+(aq)+ 2 e- 
B) Fe2+(aq)+ 2 e- → Fe(s) 
C) Cd(s)→ Cd2+(aq)+ 2 e- 
D) Cd2+(aq)+ 2 e- → Cd(s) 
A) Fe(s)→ Fe2+(aq)+ 2 e- 
B) Fe2+(aq)+ 2 e- → Fe(s) 
C) Cd(s)→ Cd2+(aq)+ 2 e- 
D) Cd2+(aq)+ 2 e- → Cd(s)

Question 10

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 11

According to the balanced equation shown below,3.00 mole of oxalic acid,H2C2O4,reacts with ________ moles of permanganate,MnO4-. 5 H2C2O4(aq)+ 2 MnO4-(aq)+ 6 H+(aq)→ 10 CO2(g)+ Mn2+(aq)+ 8 H2O(l)

Accepted Answer

A) 1.20 
B) 3.00 
C) 6.00 
D) 7.75 
A) 1.20 
B) 3.00 
C) 6.00 
D) 7.75

Question 12

What is the reduction half reaction for the following chemical reaction in a basic solution? ClO-(aq)+ Cr(OH)4-(aq)→ CrO42-(aq)+ Cl-(aq)

Accepted Answer

A) ClO-(aq)+ 2 H+(aq)+ 2e- → Cl-(aq)+ H2O(l) 
B) ClO-(aq)+ H2O(l)+ 2e- → Cl-(aq)+ 2 OH-(aq) 
C) Cr(OH)4-(aq)+ 4 OH-(aq)→ CrO42-(aq)+ 4 H2O(l)+ 3e- 
D) Cr(OH)4-(aq)→ CrO42-(aq)+ 4 H+(aq)+ 3e- 
A) ClO-(aq)+ 2 H+(aq)+ 2e- → Cl-(aq)+ H2O(l) 
B) ClO-(aq)+ H2O(l)+ 2e- → Cl-(aq)+ 2 OH-(aq) 
C) Cr(OH)4-(aq)+ 4 OH-(aq)→ CrO42-(aq)+ 4 H2O(l)+ 3e- 
D) Cr(OH)4-(aq)→ CrO42-(aq)+ 4 H+(aq)+ 3e-

Question 13

For a galvanic cell that uses the following two half-reactions, Cr2O72-(aq)+ 14 H+(aq)+ 6 e- → 2 Cr3+(aq)+ 7 H2O(l)
Pb(s)→ Pb2+(aq)+ 2 e-
How many moles of Pb(s)are oxidized by one mole of Cr2O72-?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 6 
A) 1 
B) 2 
C) 3 
D) 6

Question 14

In the galvanic cell represented by the shorthand notation shown below,
Cd(aq)|Cd2+(aq)|| I2(g)|I-(aq)|Pt(s)
the inert electrode is ________,and the balanced cathode half-reaction reaction is ________.

Accepted Answer

Pt,I₂(g)+ 2

Question 15

Using the following standard reduction potentials Fe3+(aq)+ e- → Fe2+(aq)E° = +0.77 V
Pb2+(aq)+ 2 e- → Pb(s)E° = -0.13 V
Calculate the standard cell potential for the galvanic cell reaction given below,and determine whether or not this reaction is spontaneous under standard conditions.
Pb2+(aq)+ 2 Fe2+(aq)→ 2 Fe3+(aq)+ Pb(s)

Accepted Answer

A) E° = -0.90 V,nonspontaneous 
B) E° = -0.90 V,spontaneous 
C) E° = +0.90 V,nonspontaneous 
D) E° = +0.90 V,spontaneous 
A) E° = -0.90 V,nonspontaneous 
B) E° = -0.90 V,spontaneous 
C) E° = +0.90 V,nonspontaneous 
D) E° = +0.90 V,spontaneous

Question 16

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 17

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 3.00 moles of copper metal?

Accepted Answer

A) 0.311 hours 
B) 0.621 hours 
C) 1.61 hours 
D) 3.22 hours 
A) 0.311 hours 
B) 0.621 hours 
C) 1.61 hours 
D) 3.22 hours

Question 18

A cell based on the reaction below has a standard potential of +0.42 V at 25°C.If all of the species are at standard conditions except [H+],at what pH will the cell have a potential of zero? H2O2(aq)+ 2 H+(aq)+ 2 Cl-(aq)→ Cl2(aq)+ 2 H2O(l)

Accepted Answer

A) 3.55 
B) 7.09 
C) 10.6 
D) 14.2 
A) 3.55 
B) 7.09 
C) 10.6 
D) 14.2

Question 19

Calculate the equilibrium constant,K,at 25°C for the galvanic cell reaction shown below: 8 H+(aq)+ 5 Fe2+(aq)+ MnO4-(aq)→ Mn2+(aq)+ 5 Fe3+(aq)+ 4 H2O(l)E° = +0.74 V

Accepted Answer

A) 3.2 × 10-59 
B) 3.2 × 10-10 
C) 3.2 × 1010 
D) 3.2 × 1062 
A) 3.2 × 10-59 
B) 3.2 × 10-10 
C) 3.2 × 1010 
D) 3.2 × 1062

Question 20

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:    
-Identify the electrodes and the direction of electron flow.

Accepted Answer

A) a is Ag,c is Cu and electrons flow from a to c. 
B) a is Ag,c is Cu and electrons flow from c to a. 
C) a is Cu,c is Ag and electrons flow from a to c. 
D) a is Cu,c is Ag and electrons flow from c to a. 
A) a is Ag,c is Cu and electrons flow from a to c. 
B) a is Ag,c is Cu and electrons flow from c to a. 
C) a is Cu,c is Ag and electrons flow from a to c. 
D) a is Cu,c is Ag and electrons flow from c to a.

Exam 18: Electrochemistry

Which is not true for standard electrode potentials?

For the hypothetical reaction A + Bx → Ax + B,E° = 1.19 V = and ΔG° = -115 kJ.For this reaction the value of x = .

Consider the galvanic cell shown below. -Identify the anode and cathode,and indicate the direction of ion flow to and from each electrode.

Given the half-cell potentials below,calculate the cell potential. Ag+(aq)+ e- → Ag(s)0.80 V Cu2+(aq)+ 2 e- → Cu(s)0.34 V

Galvanized steel is steel coated with a layer of

-According to Table 17.1,which will reduce water but not Mg2+?

Calculate the cell potential E at 25°C for the reaction 2 Al(s)+ 3 Fe2+(aq)→ 2 Al3+(aq)+ 3 Fe(s) Given that [Fe2+] = 0.020 M,[Al3+] = 0.10 M,and the standard reduction potential is -1.66 V for Al3+/Al and -0.45 V for Fe2+/Fe.

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 3.50 moles of copper metal?

For the galvanic cell reaction,expressed below using shorthand notation,what half-reaction occurs at the anode? Fe(s)∣ Fe2+(aq)∣∣ Cd2+(aq)∣Cd(s)

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

According to the balanced equation shown below,3.00 mole of oxalic acid,H2C2O4,reacts with ________ moles of permanganate,MnO4-. 5 H2C2O4(aq)+ 2 MnO4-(aq)+ 6 H+(aq)→ 10 CO2(g)+ Mn2+(aq)+ 8 H2O(l)

What is the reduction half reaction for the following chemical reaction in a basic solution? ClO-(aq)+ Cr(OH)4-(aq)→ CrO42-(aq)+ Cl-(aq)

For a galvanic cell that uses the following two half-reactions, Cr2O72-(aq)+ 14 H+(aq)+ 6 e- → 2 Cr3+(aq)+ 7 H2O(l) Pb(s)→ Pb2+(aq)+ 2 e- How many moles of Pb(s)are oxidized by one mole of Cr2O72-?

In the galvanic cell represented by the shorthand notation shown below, Cd(aq)|Cd2+(aq)|| I2(g)|I-(aq)|Pt(s) the inert electrode is ________,and the balanced cathode half-reaction reaction is ________.

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)?

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu2+ ions to produce 3.00 moles of copper metal?

A cell based on the reaction below has a standard potential of +0.42 V at 25°C.If all of the species are at standard conditions except [H+],at what pH will the cell have a potential of zero? H2O2(aq)+ 2 H+(aq)+ 2 Cl-(aq)→ Cl2(aq)+ 2 H2O(l)

Calculate the equilibrium constant,K,at 25°C for the galvanic cell reaction shown below: 8 H+(aq)+ 5 Fe2+(aq)+ MnO4-(aq)→ Mn2+(aq)+ 5 Fe3+(aq)+ 4 H2O(l)E° = +0.74 V

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For the hypothetical reaction A + B^x → A^x + B,E° = 1.19 V = and ΔG° = -115 kJ.For this reaction the value of x = .

Given the half-cell potentials below,calculate the cell potential. Ag⁺(aq)+ e^- → Ag(s)0.80 V Cu²⁺(aq)+ 2 e^- → Cu(s)0.34 V

-According to Table 17.1,which will reduce water but not Mg²⁺?

Calculate the cell potential E at 25°C for the reaction 2 Al(s)+ 3 Fe²⁺(aq)→ 2 Al³⁺(aq)+ 3 Fe(s) Given that [Fe²⁺] = 0.020 M,[Al³⁺] = 0.10 M,and the standard reduction potential is -1.66 V for Al³⁺/Al and -0.45 V for Fe²⁺/Fe.

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu²⁺ ions to produce 3.50 moles of copper metal?

For the galvanic cell reaction,expressed below using shorthand notation,what half-reaction occurs at the anode? Fe(s)∣ Fe²⁺(aq)∣∣ Cd²⁺(aq)∣Cd(s)

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

According to the balanced equation shown below,3.00 mole of oxalic acid,H₂C₂O₄,reacts with ________ moles of permanganate,MnO₄^-. 5 H₂C₂O₄(aq)+ 2 MnO₄^-(aq)+ 6 H⁺(aq)→ 10 CO₂(g)+ Mn²⁺(aq)+ 8 H₂O(l)

What is the reduction half reaction for the following chemical reaction in a basic solution? ClO^-(aq)+ Cr(OH)₄^-(aq)→ CrO₄^2-(aq)+ Cl^-(aq)

For a galvanic cell that uses the following two half-reactions, Cr₂O₇^2-(aq)+ 14 H⁺(aq)+ 6 e^- → 2 Cr³⁺(aq)+ 7 H₂O(l) Pb(s)→ Pb²⁺(aq)+ 2 e^- How many moles of Pb(s)are oxidized by one mole of Cr₂O₇^2-?

In the galvanic cell represented by the shorthand notation shown below, Cd(aq)|Cd²⁺(aq)|| I₂(g)|I^-(aq)|Pt(s) the inert electrode is ,and the balanced cathode half-reaction reaction is .

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)?

How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous Cu²⁺ ions to produce 3.00 moles of copper metal?

A cell based on the reaction below has a standard potential of +0.42 V at 25°C.If all of the species are at standard conditions except [H⁺],at what pH will the cell have a potential of zero? H₂O₂(aq)+ 2 H⁺(aq)+ 2 Cl^-(aq)→ Cl₂(aq)+ 2 H₂O(l)

Calculate the equilibrium constant,K,at 25°C for the galvanic cell reaction shown below: 8 H⁺(aq)+ 5 Fe²⁺(aq)+ MnO₄^-(aq)→ Mn²⁺(aq)+ 5 Fe³⁺(aq)+ 4 H₂O(l)E° = +0.74 V