Deck 17: Electrochemistry

Question 1

What species is oxidized in the reaction: CuSO₄(aq)+ Fe(s)→ FeSO₄(aq)+ Cu(s)?

A)CuSO₄ (aq)
B)Fe (s)
C)FeSO₄ (aq)
D)Cu (s)

Answer 1

Fe (s)

Question 2

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?

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^-

Answer 2

Ag(s)+ Cl^-(aq)? AgCl(s)+ e^-

Question 3

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

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

Answer 3

positive,reduction

Question 4

What is the shorthand notation that represents the following galvanic cell reaction?
Fe(s)+ Cu(NO₃)₂(aq)→ Fe(NO₃)₂(aq)+ Cu(s)

A)Fe(s)∣ Fe²⁺(aq)∣∣ Cu²⁺(aq)∣ Cu(s)
B)Cu(s)∣ Cu²⁺(aq)∣∣ Fe²⁺(aq)∣ Fe(s)
C)Fe(s)∣ NO₃^-(aq)∣∣ NO₃^-(aq)∣ Cu(s)
D)Cu(s)∣ Cu(NO₃)₂(aq)∣∣ Fe(NO₃)₂(aq)∣ Fe(s)

Question 5

Which cell involves a nonspontaneous redox reaction?

A)concentration cell
B)electrolytic cell
C)fuel cell
D)galvanic cell

Question 6

What is the shorthand notation for a galvanic cell that represents the following galvanic cell reaction?
Br₂(l)+ 2 I^-(aq)→ 2 Br^-(aq)+ I₂(s)

A)I^-(aq)|I₂(s)∣∣Br₂(l)|Br^-(aq)
B)I^-(aq)|I₂(s)∣∣Br₂(l)|Br^-(aq)|Pt(s)
C)Pt(s)|I^-(aq)|I₂(s)∣∣Br₂(l)|Br^-(aq)
D)Pt(s)|I^-(aq)|I₂(s)∣∣Br₂(l)|Br^-(aq)}Pt(s)

Question 7

A galvanic cell employs the reaction
Mg²⁺(aq)+ Cu(s)→ Mg(s)+ Cu²⁺(aq)
And NaNO₃ is the salt used in the salt bridge.During the course of the reaction

A)Na⁺ leaves the salt bridge and enters the anode compartment.
B)NaNO₃ leaves the salt bridge and enters the anode compartment.
C)Na⁺ leaves the salt bridge and enters the cathode compartment.
D)NaNO₃ leaves the salt bridge and enters the cathode compartment.

Question 8

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

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 9

The iron content of foods can be determined by dissolving them in acid (forming Fe³⁺),reducing the iron(III)to iron(II),and titrating with cerium(IV):
Fe²⁺(aq)+ Ce⁴⁺(aq)→ Fe³⁺(aq)+ Ce³⁺(aq).
Identify the two half-reactions in the above reaction.

A)oxidation half-reaction reduction half-reaction Fe²⁺(aq)+ e^-→ Fe³⁺(aq)Ce⁴⁺(aq)→ Ce³⁺(aq)+ e^-
B)oxidation half-reaction reduction half-reaction Fe²⁺(aq)→ Fe³⁺(aq)+ e^- Ce⁴⁺(aq)+ e^- → Ce³⁺(aq)
C)oxidation half-reaction reduction half-reaction Ce⁴⁺(aq)+ e^- → Ce³⁺(aq)Fe²⁺(aq)→ Fe³⁺(aq)+ e^-
D)oxidation half-reaction reduction half-reaction Ce⁴⁺(aq)→ Ce³⁺(aq)+ e^- Fe²⁺(aq)+ e^- → Fe³⁺(aq)

Question 10

In a galvanic cell,the half-reaction H₂(g)+ 2 OH^-(aq)→ 2 H₂O(l)+ 2 e^- is

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 11

For the galvanic cell reaction,expressed below using shorthand notation,what half-reaction occurs at the cathode?
Zn(s)∣ Zn²⁺(aq)∣∣ Ni²⁺(aq)∣ Ni(s)

A)Zn(s)→ Zn²⁺(aq)+ 2 e^-
B)Zn²⁺(aq)+ 2 e^- → Zn(s)
C)Ni(s)→ Ni²⁺(aq)+ 2 e^-
D)Ni²⁺(aq)+ 2 e^- → Ni(s)

Question 12

In the shorthand notation for a galvanic cell,a double vertical line (∣∣)represents

A)a double phase boundary
B)an inert electrode
C)a phase boundary
D)a salt bridge

Question 13

What is the reduction half-reaction for the following overall cell reaction?
Ni²⁺(aq)+ 2 Ag(s)→ Ni(s)+ 2 Ag⁺(aq)

A)Ag(s)+ e^- → Ag⁺(aq)
B)Ag⁺(aq)+ e^- → Ag(s)
C)Ni²⁺(aq)+ 2 e^- → Ni(s)
D)Ni²⁺(aq)+ e^- → Ni(s)

Question 14

Which of the following terms can be used to describe an electrochemical cell in which a spontaneous chemical reaction generates an electric current?
I.an electrolytic cell
II.a galvanic cell
III.a voltaic cell

A)only I
B)only II
C)only III
D)II and III

Question 15

A salt bridge is used to

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 16

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-?

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

Question 17

During an electrochemical reaction,electrons move through the external circuit toward the ________ and positive ions in the cell move toward the ________.

A)anode,anode
B)anode,cathode
C)cathode,anode
D)cathode,cathode

Question 18

What is the shorthand notation that represents the following galvanic cell reaction?
2 Fe²⁺(aq)+ Cl₂(g)→ 2 Fe³⁺(aq)+ 2 Cl^-(aq)

A)Fe²⁺(aq)∣ Fe³⁺(aq)∣∣ Cl₂(g)∣ Cl^-(aq)
B)Fe(s)∣ Fe²⁺(aq)∣∣ Fe³⁺(aq)Cl₂(g)∣ Cl^-(aq)∣ C(s)
C)Pt(s)∣ Fe³⁺(aq),Fe²⁺(aq),Cl₂(g)∣∣ Cl^-(aq)∣ C(s)
D)Pt(s)∣ Fe²⁺(aq),Fe³⁺(aq)∣∣ Cl₂(g)∣ Cl^-(aq)∣ C(s)

Question 19

The shorthand notation for the galvanic cell reaction Fe³⁺(aq)+ 2 I^-(aq)→ Fe²⁺(aq)+ I₂(s)requires an inert electrode on

A)both sides of the salt bridge
B)neither side of the salt bridge
C)only on the left side of the salt bridge
D)only on the right side of the salt bridge

Question 20

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below?
Pt(s)|Sn²⁺(aq)|Sn⁴⁺(aq)∣∣Br₂(l)|Br^-(aq)|Pt(s)

A)Sn²⁺(aq)+ Br₂(l)→ Sn⁴⁺(aq)+ 2 Br^-(aq)
B)Sn²⁺(aq)+ 2 Br^-(aq)→ Sn⁴⁺(aq)+ Br₂(l)
C)Sn⁴⁺(aq)+ Br₂(l)→ Sn²⁺(aq)+ 2 Br^-(aq)
D)Sn⁴⁺(aq)+ 2 Br^-(aq)→ Sn²⁺(aq)+ Br₂(l)

Question 21

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

Question 22

For the galvanic cell reaction,expressed below using shorthand notation,what half-reaction occurs at the anode?
Mg(s)∣ Mg²⁺(aq)∣∣ Cd²⁺(aq)∣Cd(s)

A)Mg(s)→ Mg²⁺(aq)+ 2 e^-
B)Mg²⁺(aq)+ 2 e^- → Mg(s)
C)Cd(s)→ Cd²⁺(aq)+ 2 e^-
D)Cd²⁺(aq)+ 2 e^- → Cd(s)

Question 23

For the reaction 2 Al(s)+ 3 Co²⁺(aq)→ 2 Al³⁺(aq)+ 3 Co(s),ΔG° is -799 kJ.What is E° for a standard cell based on this reaction?

A)+1.38 V
B)+2.76 V
C)+4.14 V
D)+8.28 V

Question 24

What is the standard cell potential for the reaction below?
Mg(s)+ Br₂(l)→ Mg²⁺(aq)+ 2 Br^-(aq)
The standard reduction potential is -2.37 V for the Mg²⁺/Mg half-cell and +1.09 V for the Br₂/Br^- half-cell.

A)-3.46 V
B)-1.28 V
C)+1.28 V
D)+3.46 V

Question 25

What is the relationship between the standard cell potentials,E°,for the following two galvanic cell reactions?
I.2 Ag⁺(aq)+ Sn²⁺(aq)→ Sn⁴⁺(aq)+ 2 Ag(s)
II.Ag(s)+ 1/2 Sn⁴⁺(aq)→ 1/2 Sn²⁺(aq)+ Ag⁺(aq)

A)E°(I)= E°(II)
B)E°(I)= 2E°(II)
C)E°(I)= - E°(II)
D)E°(I)= - 2E°(II)

Question 26

Which is not true for standard electrode potentials?

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.

Question 27

What is the relation between joules (J),volts (V),and coulombs (C)?

A)1 J = 1 V × 1 C
B)1 J = 1 V ÷ 1 C
C)1 J = 1 C ÷ 1 V
D)1 J = 1 V × 1 C²

Question 28

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?

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

Question 29

For the galvanic cell Pt(s)∣ Sn²⁺(aq),Sn⁴⁺(aq)∣∣ Pb²⁺(aq)∣ Pb(s),what is the function of the Pt(s)?

A)Pt is the anode and is a reactant in the overall cell reaction.
B)Pt is the anode and does not appear in the overall cell reaction.
C)Pt is the cathode and is a product in the overall cell reaction.
D)Pt is the cathode and does not appear in the overall cell reaction.

Question 30

The nickel-cadmium battery cell has a standard potential of +1.20 V.The cell reaction is
2 NiO(OH)(s)+ Cd(s)+ 2 H₂O(l)→ 2 Ni(OH)₂(s)+ Cd(OH)₂(s).
What is the standard free energy change for this reaction?

A)-38.7 kJ
B)-116 kJ
C)-232 kJ
D)-463 kJ

Question 31

What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand notation below?
Al(s)∣ Al³⁺(aq)∣∣ Ni²⁺(aq)∣ Ni(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 32

In the relationship ΔG = -nFE°,what is the value of n for the reaction shown below?
3 Cu^2+(aq)+ 2 Al(s)→ 3 Cu(s)+ 2 Al³⁺(aq)

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

Question 33

Doubling all the coefficients in the equation for the cell reaction

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 34

For the hypothetical reaction A + 2 B^x → A^y + 2 B,E° = 1.50 V = and ΔG° = -305 kJ.For this reaction,if the value of x is 4,then the value of y = .

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

Question 35

A galvanic cell consists of a La³⁺/La half-cell and a standard hydrogen electrode.If the La³⁺/La half-cell standard cell functions as the anode,and the standard cell potential is 2.52 V,what is the standard reduction potential for the La³⁺/La half-cell?

A)-2.52 V
B)-0.84 V
C)+0.84 V
D)+2.52 V

Question 36

What is the relationship between the standard cell potentials,E°,for the following two galvanic cell reactions?
I.3 Cu^2+(aq)+ 2 Al(s)→ 3 Cu(s)+ 2 Al³⁺(aq)
II.6 Cu^2+(aq)+ 4 Al(s)→ 6 Cu(s)+ 4 Al³⁺(aq)

A)E°(I)= E°(II)
B)E°(I)= E°(II)
C)E°(I)= 2E°(II)
D)E°(I)= E°(II)²

Question 37

What is the balanced equation for the galvanic cell reaction expressed using shorthand notation below?
Mg(s)∣ Mg²⁺(aq)∣∣ Cl₂(g)∣ Cl^-(aq)∣ C(s)

A)Mg(s)+ 2 Cl^-(aq)→ Mg²⁺(aq)+ Cl₂(g)
B)Mg(s)+ Cl₂(g)→ Mg²⁺(aq)+ 2 Cl^-(aq)
C)Mg²⁺(aq)+ 2 Cl^-(aq)→ Mg(s)+ Cl₂(g)
D)Mg²⁺(aq)+ 2 Cl^-(aq)→ MgCl₂(s)

Question 38

What is the relation between ΔG° and E° for the cell reaction below?
Ni²⁺(aq)+ Cd(s)→ Cd²⁺(aq)+ Ni(s)

A)ΔG° = F E°
B)ΔG° = 2 F E°
C)ΔG° = -F E°
D)ΔG° = -2 F E°

Question 39

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 = .

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

Question 40

Write the overall cell reaction for the galvanic cell given below.
Pt(s)∣ H₂(g)∣ H⁺(aq)∣∣ Cl₂(g)∣ Cl^-(aq)∣ Pt(s)

A)Pt(s)+ H₂(g)+ Cl^-(aq)→ Pt(s)+ 2 H⁺(aq)+ 2 Cl₂(g)
B)2 H⁺(aq)+ 2 Cl₂(g)→ 2 HCl(aq)
C)H₂(g)+ Cl₂(g)→ 2 H⁺(aq)+ 2 Cl^-(aq)
D)No reaction would occur because there is no salt bridge.

Question 41

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)

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 42

Based on the half-reactions and their respective standard reduction potentials below,which addition to an aqueous solution containing Fe(NO₃)₂ will result in a reaction under standard-state conditions?
O₂(g)+ 4 H⁺ +4 e^- → 2 H₂O(l)1.23 V
Fe³⁺(aq)+ e^- → Fe²⁺(aq)0.77 V
Cu²⁺(aq)+ 2 e^- → Cu(s)0.34 V
2 H⁺(aq)+ 2 e^- → H₂(g)0.00 V
Ni²⁺(aq)+ + 2 e^- → Ni(s)-0.26 V
Fe²⁺(aq)+ 2 e^- → Fe(s)-0.45 V

A)aqueous copper(II)acetate
B)nickel wire
C)hydrogen gas
D)oxygen gas

Question 43

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

A)Al³⁺(aq)
B)Al(s)
C)Na⁺(aq)
D)Na(s)

Question 44

What is the Al³⁺:Ag⁺concentration ratio in the cell Al(s)| Al³⁺(aq)∣∣ Ag⁺(aq)| Ag(s)if the measured cell potential is 2.34 V?

A)0)0094:1
B)0)21:1
C)4)7:1
D)110:1

Question 45

Calculate the value of the reaction quotient,Q,for the galvanic cell expressed using shorthand notation below.Use the balanced chemical equation that has the smallest whole number stoichiometric coefficients.
Zn(s)∣ Zn²⁺(aq,0.0100 M)∣∣ Ag+(aq,1.25 M)∣ Ag(s)

A)156
B)125
C)8)00 × 10^-3
D)6)40 × 10^-3

Question 46

Consider the galvanic cell,Pt(s)| H₂(1 atm)| H⁺(1 M)|| Cl^-(1 M)| Hg₂Cl₂(s)| Hg(l).Which one of the following changes to the cell would cause the cell potential to increase (i.e. ,become more positive)?

A)decrease the mass of Pt
B)increase the mass of Pt
C)decrease the pH
D)increase the pH

Question 47

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)Ag,Cd²⁺
B)Ag⁺,Cd
C)Cd,Ag⁺
D)Cd²⁺,Ag

Question 48

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

A)Ag(s)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 49

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)?

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 50

Use Table 17.1 to calculate the standard potential for the reaction
O₂(g)+ 4 H⁺(aq)+ 2 Cu(s)→ 2 Cu²⁺(aq)+ 2 H₂O(l).

A)-1.57 V
B)-0.89 V
C)+0.89 V
D)+1.57 V

Question 51

Based on the following information,
F₂(g)+ 2 e^- → 2 F^-(aq)E° = +2.87 V
Mg²⁺(aq)+ 2 e^- → 2 Mg(s)E° = -2.37 V
Which of the following chemical species is the strongest reducing agent?

A)F₂(g)
B)Mg²⁺(aq)
C)F^-(aq)
D)Mg(s)

Question 52

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

A)Fe³⁺
B)I₂
C)MnO₄^-
D)Pb²⁺

Question 53

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,

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 54

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.

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

Question 55

Based on the half-reactions and their respective standard reduction potentials below,what is the standard cell potential for the reaction that is expected to occur?
Fe³⁺(aq)+ e^- → Fe²⁺(aq)0.77 V
Sn⁴⁺(aq)+ 2 e^- → Sn²⁺(aq)0.15 V
Pb²⁺(aq)+ 2 e^- → Pb(s)-0.13 V

A)0)28 V
B)0)64 V
C)0)90 V
D)1)03 V

Question 56

Given: Ag⁺(aq)+ e^- → Ag(s)E° = +0.799 V
AgI(s)+ e^- → Ag(s)+ I^-(aq)E° = -0.152 V
Ni²⁺(aq)+ 2 e^- → Ni(s)E° = -0.267 V
Which of the following reactions should be spontaneous under standard conditions?
I.2 AgI(s)+ Ni(s)→ 2 Ag(s)+ 2 I^-(aq)+ Ni²⁺(aq)
II.Ag+(aq)+ I^-(aq)→ AgI(s)

A)I and II are both nonspontaneous.
B)I is nonspontaneous and II is spontaneous.
C)I is spontaneous and II is nonspontaneous.
D)I and II are both spontaneous.

Question 57

According to Table 17.1,which aqueous metal ion will reduce Ag⁺,but not Cu²⁺?

A)Fe²⁺
B)Fe³⁺
C)Mn²⁺
D)Sn²⁺

Question 58

Using Table 17.1,find E° for 2 H₂O(l)→ 2 H₂(g)+ O₂(g).

A)-2.06 V
B)-1.23 V
C)-0.80 V
D)-0.40 V

Question 59

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.

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

Question 60

Consider the following table of standard half-cell potentials:
A₂ + 2 e^- → 2 A^- E° = + 1.09 V
B⁴⁺ + 2 e^- → B²⁺ E° = + 0.15 V
C³⁺ + 3 e^- → C E° = - 1.66 V
D²⁺ + 2 e^- → D E° = - 2.37 V
Which substance is the strongest oxidizing agent?

A)A₂
B)B⁴⁺
C)C³⁺
D)D²⁺

Question 61

Given that E° = +0.897 V,calculate E at 25°C for
Pb(s)∣ Pb²⁺(0.0400 M)∣∣ Fe³⁺(0.200 M),Fe²⁺(0.0100 M)∣ Pt(s)

A)+0.779 V
B)+0.935 V
C)+1.015 V
D)+1.134 V

Question 62

Which battery does not use MnO₂(s)as a cell reactant?

A)an alkaline dry cell.
B)a Leclanche' dry cell.
C)a lithium battery.
D)a "ni-cad" battery.

Question 63

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?

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

Question 64

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)

A)3)55
B)7)09
C)10.6
D)14.2

Question 65

Consider the following cell:
Pt(s)∣ H₂(g,p₁)∣ H⁺(aq,pH_A)∣∣ H⁺(aq,pH_C)∣ H₂(g,p₂)∣ Pt(s)
Where pH_A is the pH of the aqueous solution in the anode half-cell and pH_C is the pH of the aqueous solution in the cathode half-cell.If the partial pressure of H₂(g)is the same for both half-cells, (p₁ = p₂),then E for the cell at 25°C is

A)0)0296 V log (pH_A/pH_C).
B)0)0296 V log (pH_C/pH_A).
C)0)0592 V (pH_A - pH_C).
D)0)0592 V (pH_C - pH_A).

Question 66

The cell reaction for a lead storage battery is:
Pb(s)+ PbO₂(s)+ 2 H⁺(aq)+ 2 HSO₄^-(aq)→ 2 PbSO₄(s)+ 2 H₂O(l)
E° = +1.92 V
To provide a potential of about 12 V,one could

A)adjust the pH to 12.
B)adjust the pH to 1.
C)connect six cells in series.
D)greatly increase the surface area of the Pb(s)and PbO₂(s).

Question 67

Given that E°_red = -0.26 V for Ni²⁺/Ni at 25°C,find E° and E for the concentration cell expressed using shorthand notation below.
Ni(s)∣ Ni²⁺(aq,1.0 × 10^-5 M)∣∣ Ni²⁺(aq,0.100 M)∣ Ni(s)

A)E° = 0.00 V and E = +0.24 V
B)E° = 0.00 V and E = +0.12 V
C)E° = -0.26 V and E = -0.02 V
D)E° = -0.26 V and E = -0.14 V

Question 68

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

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

Question 69

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

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 70

Given p_H2 = 0.100 atm,[Cd²⁺] = 0.200 M,and [H⁺] = 1.00 × 10^-5 M,calculate E at 25°C for a cell based on the reaction:
Cd(s)+ 2 H⁺(aq) $\rarr$ H₂(g)+ Cd²⁺(aq)E^o = +0.40 V.

A)-0.09 V
B)+0.12 V
C)+0.15 V
D)+0.30 V

Question 71

The equilibrium constant,K,can be calculated from

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

Question 72

At 25°C,E° = +1.88 V for a cell based on the reaction
3 AgCl(s)+ Al(s)→ 3 Ag(s)+ Al³⁺(aq)+ 3 Cl^-(aq).
Find the cell potential E if [Al³⁺] = 0.20 M and [Cl^-] = 0.010 M.

A)+2.01 V
B)+2.04 V
C)+2.28 V
D)cannot be calculated without the amounts of AgCl,Al,and Ag

Question 73

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?

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

Question 74

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

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

Question 75

Consider the half-reaction: MnO₄^- (aq)+ 8 H⁺ (aq)+ 5 e^- → Mn²⁺ (aq)+ 4 H₂O(l).The formation of MnO₄^- from Mn²⁺ occurs most readily when the solution is

A)acidic.
B)neutral.
C)basic.
D)The reaction is not dependent upon pH.

Question 76

When a cell reaction reaches equilibrium,

A)E° = 0.
B)E = 0.
C)both E° and E = 0.
D)neither E° nor E = 0.

Question 77

Ag⁺(aq)+ e^- → Ag(s)E° = +0.800 V
AgBr(s)+ e^- → Ag(s)+ Br^-(aq)E° = +0.071 V
Br₂(l)+ 2 e^- → 2 Br^-(aq)E° = +1.066 V
Use some of the data above to calculate K_sp at 25°C for AgBr.

A)6.3 × 10^-2
B)4.9 × 10^-13
C)1.9 × 10^-15
D)(^2.4 × 10^-34)

Question 78

How many moles of electrons,n,are transferred in the following reduction-oxidation reaction?
2 MnO₄^-(aq)+ 16 H⁺(aq)+ 10 Cl^-(aq)→ 2 Mn²⁺(aq)+ 5 Cl₂(g)+ 8 H₂O(l)

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

Question 79

For a particular battery based on one of the following reactions,E is expected to remain constant with time until the cell reactants are almost completely consumed.Which is the appropriate reaction?

A)Zn(s)+ 2 MnO₂(s)+ 2 NH₄⁺(aq)→ 2 NH₃(aq)+ Mn₂O₃(s)+ Zn²⁺(aq)+ H₂O(l)
B)2 NiO(OH)(s)+ Cd(s)+ 2 H₂O(l)→ 2 Ni(OH)₂(s)+ Cd(OH)₂(s)
C)Pb(s)+ PbO₂(s)+ 2 H⁺(aq)+ 2 HSO₄^-(aq)→ 2 PbSO₄(s)+ 2 H₂O(l)
D)Zn(s)+ Cu²⁺(aq)→ Zn²⁺(aq)+ Cu(s)

Question 80

If the cell reaction involves ions in solution,as the cell reaction in a galvanic cell continues,

A)E for the cell increases.
B)E for the cell decreases.
C)E° for the cell increases.
D)E° for the cell decreases.