Deck 19: Electrochemistry

Question 1

When the following equation is balanced with the lowest whole number coefficients,the coefficients are: Cu(s)+ H⁺(aq)+ NO₃^-(aq)→ NO(g)+ H₂O(l)+ Cu²⁺(aq)

A)1,2,1,1,1,1
B)3,2,1,1,1,3
C)3,2,4,2,4,3
D)1,8,2,2,4,1
E)3,8,2,2,4,3

Answer 1

3,8,2,2,4,3

Question 2

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)

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

Answer 2

10

Question 3

What is the oxidizing agent in the (unbalanced)reaction? Cu(s)+ H⁺(aq)+ NO₃^-(aq)→ NO(g)+ H₂O(l)+ Cu²⁺(aq)

A)Cu
B)H⁺
C)NO₃^-
D)NO
E)Cu²⁺

Answer 3

NO₃^-

Question 4

Which statement is correct?

A)The cathode is the electrode where the oxidation takes place.
B)The cathode is the electrode where the reduction takes place.
C)Both oxidation and reduction make take place at the cathode,depending on the cell.
D)The cathode is always positive.
E)The anode is always negative.

Question 5

If a substance is reduced,it must undergo a

A)gain of electrons.
B)loss of oxygen.
C)gain of hydrogen.
D)loss of electrons.
E)gain of oxygen.

Question 6

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient of Zn(s)? Zn(s)+ ReO₄^-(aq)→ Re(s)+ Zn²⁺(aq) (acidic solution)

A)2
B)7
C)8
D)16
E)None of these choices is correct.

Question 7

Complete and balance the following redox equation.When properly balanced using the smallest whole-number coefficients,the coefficient of S is H₂S + HNO₃ → S + NO + H₂O (acidic solution)

A)1.
B)2.
C)3.
D)5.
E)6.

Question 8

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

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 9

When the following redox equation is balanced using the smallest whole-number coefficients,what is the coefficient of NO₂? Sn + HNO₃ → SnO₂ + NO₂ + H₂O (acidic solution)

A)1
B)2
C)3
D)4
E)5

Question 10

Consider the following redox equation. Mn(OH)₂(s)+ MnO₄^-(aq)→ MnO₄^2-(aq) (basic solution)
When the equation is balanced with the smallest whole number coefficients,what is the coefficient for OH^-(aq)and on which side of the equation is OH^-(aq)present?

A)4,reactant side
B)4,product side
C)6,reactant side
D)6,product side
E)8,reactant side

Question 11

When the following redox equation is balanced with the smallest whole number coefficients,the coefficient for the hydrogen sulfate ion will be ______. Al(s)+ HSO₄^-(aq)+ OH^-(aq)→ Al₂O₃(s)+ S^2-(aq)+ H₂O(l)

A)1
B)3
C)4
D)6
E)8

Question 12

Which is not a redox reaction?

A)Al(OH)₄^-(aq)+ 4H⁺(aq)→ Al³⁺(aq)+ 4H₂O(l)
B)C₆H₁₂O₆(s)+ 6O₂(g)→ 6CO₂(g)+ 6H₂O(l)
C)Na₆FeCl₈(s)+ 2Na(l)→ 8NaCl(s)+ Fe(s)
D)2H₂O₂(aq)→ 2H₂O(l)+ O₂(g)
E)CO₂(g)+ H₂(g)→ CO(g)+ H₂O(g)

Question 13

Complete and balance the following redox equation using the set of smallest whole numbers coefficients.What is the sum of the coefficients? HI + HNO₃ → I₂ + NO (acidic solution)

A)5
B)7
C)14
D)17
E)None of these choices is correct.

Question 14

What is the name given to the apparatus where oxidation occurs in a cell where electricity flows?

A)Cathode
B)Electrode
C)Galvanic cell
D)Anode
E)Voltaic cell

Question 15

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient of Sn(OH)₃^-? Bi(OH)₃(s)+ Sn(OH)₃^-(aq)→ Sn(OH)₆^2-(aq)+ Bi(s) (basic solution)

A)1
B)2
C)3
D)6
E)12

Question 16

Consider the following balanced redox reaction. Mn²⁺(aq)+ S₂O8^2-(aq)+ 2H₂O(l)→ MnO₂(s)+ 4H⁺(aq)+ 2SO₄^2-(aq)
Which of the following statements is true?

A)Mn²⁺(aq)is the oxidizing agent and is reduced.
B)Mn²⁺ (aq)is the oxidizing agent and is oxidized.
C)Mn²⁺ (aq)is the reducing agent and is oxidized.
D)Mn²⁺ (aq)is the reducing agent and is reduced.
E)Manganese does not change its oxidation number in this reaction.

Question 17

Consider the reaction CuO(s)+ H₂(g)→ Cu(s)+ H₂O(l)
In this reaction,which substances are the oxidizing agent and reducing agent,
Respectively?

A)CuO and H₂
B)H₂ and CuO
C)CuO and Cu
D)H₂O and H₂
E)Cu and H₂O

Question 18

When the following redox equation is balanced with the smallest whole number coefficients,what is the coefficient of Sb³⁺(aq)? BrO₃^-(aq)+ Sb³⁺(aq)→ Br^-(aq)+ Sb⁵⁺(aq) (acidic solution)

A)1
B)2
C)3
D)4
E)6

Question 19

Complete and balance the following redox equation.Now sum the coefficients of all species in the balanced equation.(Remember to add the coefficients that are equal to one,and to add the coefficients of any species added to the equation.)The sum of the smallest whole number coefficients is Bi(OH)₃ + SnO₂^2- → Bi + SnO₃^2- (basic solution)

A)32
B)25
C)16
D)13
E)4

Question 20

What is the name given to the experimental apparatus for generating electricity through the use of a spontaneous reaction?

A)Electrolytic cell
B)Galvanic cell
C)Redox cell
D)Cathode
E)Anode

Question 21

The redox reaction of peroxydisulfate with iodide has been used for many years as part of the iodine clock reaction.If E°_cell = 1.587 V and E° of the cathode half-cell is 0.536 V, what is E° of the anode half-cell?
S₂O₈^2-(aq)+ 2H⁺ + 2I^-(aq)→ 2HSO₄^-(aq)+ I₂(aq)

A)-1.051 V
B)-2.123 V
C)1.051 V
D)2.123 V
E)None of these choices is correct.

Question 22

What is E°_cell for a galvanic cell represented by the combination of the following half-reactions? 2Hg²⁺(aq)+ 2e^-
Hg₂²⁺(aq)E°= 0.92V
Cr³⁺(aq)+ 3e^- Cr(s)E°= -0.74V

A)-0.18 V
B)0.18 V
C)1.28 V
D)1.66 V
E)2.12 V

Question 23

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

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

Question 24

What is E°_cell for the following reaction? 2Au(s)+ 3Ca²⁺(aq)→ 2Au³⁺(aq)+ 3Ca(s)
Au³⁺(aq)+ 3e^- → Au(s)E° = 1.50 V
Ca²⁺ (aq)+ 2e^- → Ca(s)E° = -2.87 V

A)-4.37 V
B)-1.37 V
C)-11.6 V
D)1.37 V
E)4.37 V

Question 25

Which is incorrect?

A)At equilibrium,E_cell = 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 26

Which is the correct cell notation for the following reaction? Au³⁺(aq)+ Al(s)→ Al³⁺(aq)+ Au(s)

A)Al³⁺(aq)|Al(s)||Au³⁺(aq)|Au(s)
B)Al(s)|Al³⁺(aq)||Au³⁺(aq)|Au(s)
C)Al³⁺(aq)|Au³⁺(aq)||Al(s)|Au(s)
D)Al³⁺(aq)|Au(s)||Au³⁺(aq)|Al(s)
E)Au(s)|Al(s)||Au³⁺(aq)|Al³⁺(aq)

Question 27

What is the purpose of a salt bridge in an electrochemical cell?

A)A salt bridge provides electrical contact between the electrodes that make up the cell.
B)A salt bridge carries electrons between the cathode and anode.
C)A salt bridge insulates the two electrodes.
D)A salt bridge allows the electrolyte solution to siphon from one side of the cell to the other so the levels remain equal.
E)A salt bridge allows electrolyte to flow from one half-cell to the other in order to maintain electroneutrality.

Question 28

What is the name given to the apparatus where reduction occurs in a cell where electricity flows?

A)Cathode
B)Electrode
C)Galvanic cell
D)Anode
E)Voltaic cell

Question 29

If E° for X + e^- → Y is larger than E° for A + 2e^- → B,then in a spontaneous process under standard-state conditions,

A)X will oxidize A.
B)Y will oxidize A.
C)Y will reduce A.
D)B will oxidize X.
E)B will reduce X.

Question 30

A voltaic cell is prepared using copper and silver.Its cell notation is shown below. Cu(s)| Cu²⁺(aq)|| Ag⁺(aq)| Ag(s)
Which reaction occurs at the cathode?

A)Cu(s)→ Cu²⁺(aq)+ 2e^-
B)Cu²⁺(aq)+ 2e^- → Cu(s)
C)Ag(s)→ Ag⁺(aq)+ e^-
D)Ag⁺(aq)+ e^- → Ag(s)
E)Cu(s)+ 2Ag⁺(aq)→ Cu²⁺(aq)+ 2Ag(s)

Question 31

A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s)| Al³⁺(aq)|| Ni²⁺(aq)| Ni(s)
Which reaction occurs at the anode?

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

Question 32

What is E°_cell for the following reaction? 2 Ag(s)+ Sn²⁺(aq)→ 2 Ag⁺(aq)+ Sn(s)
Ag⁺(aq)+ e^- → Ag(s)E° = 0.80 V
Sn⁴⁺(aq)+ 2e^? →Sn²⁺(aq)E° = 0.13 V
Sn²⁺(aq)+ 2e^- → Sn(s)E° = -0.14 V

A)+0.94 V
B)-0.94 V
C)+0.67 V
D)-0.67 V
E)+1.34 V

Question 33

What is E°_cell for a galvanic cell represented by the combination of the following half-reactions? ClO₄^-(aq)+ 8 H⁺(aq)+8e^-
Cl^-(aq)+4H₂O(l)E° = 1.389V
VO₂⁺(aq)+ 2H⁺(aq)+e^-
VO⁺(aq)+H₂O(l)E° = 0.991V

A)-0.398 V
B)-2.380 V
C)0.398 V
D)2.380 V
E)6.539 V

Question 34

Based on the data presented below,which is the strongest oxidizing agent? [PtCl₄]^2-(aq)+ 2e^-
Pt(s)+ 4Cl^-(aq)E° = 0.755V
RuO₄(s)+ 8H⁺(aq)+ 8e^- Ru(s)+ 4H₂O(l)E° = 1.038V
FeO₄^2-(aq)+ 8H⁺(aq)+ 3e^- Fe³⁺(aq)+4H₂O(l)E° = 2.07 V
H₄XeO₆(aq)+ 2H⁺(aq)+ 2e^- XeO₃(aq)+3H₂O(l)E° = 2.42 V

A)[PtCl₄]^2-(aq)
B)RuO₄(s)
C)HFeO₄^-(aq)
D)H₄XeO₆(aq)
E)Cl^-(aq)

Question 35

A cell can be prepared from copper and tin.What is the E°_cell for the galvanic cell that forms from the following half-reactions? Cu²⁺(aq)+ 2e^- Cu(s)E° = 0.34V
Sn⁴⁺(aq)+ 2e^- Sn²⁺(aq)E° = 0.13V

A)0.47 V
B)0.21 V
C)-0.21 V
D)-0.47 V
E)0.42 V

Question 36

What is E°_cell for the following reaction? Al(s)+ 3Ag⁺(aq)→ Al³⁺(aq)+ 3Ag(s)
Al³⁺(aq)+ 3e^- →Al(s)E° = -1.66 V
Ag⁺(aq)+ e^- →Ag(s)E° = 0.80 V

A)-2.46 V
B)0.86 V
C)-0.86 V
D)2.46 V
E)4.06 V

Question 37

What is meant by SHE?

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

Question 38

The voltaic cell composed of Co(s),Co²⁺(aq),Cu(s),and Cu²⁺(aq)has E°_cell = 0.62 V.If E° of the cathode half-cell is 0.34 V,what is E° of the anode half-cell? Cu²⁺(aq)+ Co(s)→ Cu(s)+ Co²⁺(aq)

A)-0.28 V
B)-0.96 V
C)0.28 V
D)0.96 V
E)0.21 V

Question 39

A certain electrochemical cell has for its cell reaction: Zn + HgO → ZnO + Hg
Which is the half-reaction occurring at the anode?

A)HgO + 2e^- → Hg + O^2-
B)Zn²⁺+ 2e^- → Zn
C)Zn → Zn²⁺ + 2e^-
D)ZnO + 2e^- → Zn

Question 40

What is the name given to the apparatus that connects the two solutions by a conducting medium through which the cations and anions can move from one half-cell to the other?

A)Cathode
B)Electrode
C)Galvanic cell
D)Salt bridge
E)Fuel cell

Question 41

What is the equilibrium constant at 25°C for the following reaction? (R = 8.314 J/K • mol,F = 96,500 C • mol^-1)
2Cr(s)+ 3Pb²⁺(aq) 3Pb(s)+2Cr³⁺(aq)E°_cell = 0.61V

A)4.1 × 10²⁰
B)8.2 × 10³⁰
C)3.3 × 10⁵¹
D)6.7 × 10⁶¹
E)> 9.9 × 10⁹⁹

Question 42

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

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 43

Consider the reaction of iodine with manganese dioxide. 3I₂(s)+ 2MnO₂(s)+ 8OH^-(aq) 6I^-(aq)+ 2MnO₄^-(aq)+ 4H₂O(l)
The equilibrium constant for the overall reaction is 8.3 × 10^-7.What is E°_cell for the reaction at 25°C? (R = 8.314 J/K • mol,F = 96,500 C • mol^-1)

A)-0.36 V
B)-0.18 V
C)-0.12 V
D)-0.060 V
E)+0.12 V

Question 44

What is E°_cell for the reaction of nickel(II)ions with cadmium metal at 25°C? (R = 8.314 J/K • mol,F = 96,500 C • mol^-1)
Ni²⁺(aq)+ Cd(s) Cd²⁺(aq)+ Ni(s)K = 1.17 × 10⁵

A)0.0750 V
B)0.100 V
C)0.120 V
D)0.150 V
E)0.300 V

Question 45

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

Question 46

What is ΔG° at 298 K for the following reaction? (F = 96,500 C • mol^-1) 2Cr³⁺(aq)+ 6Hg(l)→ 2Cr(s)+ 3Hg₂²⁺(aq)E°_cell = 1.59V

A)-921 kJ/mol
B)-767 kJ/mol
C)-460 kJ/mol
D)-307 kJ/mol
E)-1840 kJ/mol

Question 47

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.

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

Question 48

What is the equilibrium constant at 25°C for the following reaction? (R = 8.314 J/K • mol,F = 96,500 C • mol^-1)
Sn²⁺(aq)+ Fe(s) Sn(s)+ Fe²⁺(aq)E°_cell = 0.30V

A)1.2 × 10⁵
B)1.4 × 10¹⁰
C)8.6 × 10^-6
D)7.1 × 10^-11
E)2.3 × 10²³

Question 49

Given the following standard reduction potentials, Ag⁺(aq)+ e^- → Ag(s)E° = +0.80 V
AgCN(s)+ e^- → Ag(s)+ CN^-(aq)E° = -0.01 V
Calculate the solubility product of AgCN at 25°C.

A)4.3 × 10^-14
B)2.3 × 10¹³
C)2.1 × 10^-14
D)5.1 × 10¹³
E)None of these choices is correct.

Question 50

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

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

Question 51

Which metals may be oxidized by H⁺ under standard-state conditions? Ag⁺(aq)+ e^- →Ag(s)E° = 0.80 V
Cu²⁺ (aq)+ 2e^- →Cu(s)E° = 0.34 V
Sn²⁺(aq)+ 2e^- →Sn(s)E° = -0.14 V
Zn²⁺(aq)+ 2e^- →Zn(s)E° = -0.76 V

A)Ag,Cu,Sn,and Zn
B)Ag and Cu
C)Sn and Cu
D)Zn and Cu
E)Zn and Sn

Question 52

What is the cell potential at 25°C for the following reaction if [Zn²⁺] = 1.0 × 10^-4 M and [Sn²⁺] = 0.20 M ? (R = 8.314 J/K • mol,F = 96,500 C • mol^-1) Zn²⁺(aq)+ Sn(s)→ Zn(s)+ Sn²⁺(aq)E°_cell = -0.62 V

A)-0.62 V
B)+0.52 V
C)-0.52 V
D)-0.72 V
E)+0.72 V

Question 53

Based on the data presented below,which is the strongest reducing agent? PbI₂(s)+ 2e^- Pb(s)+2I^-(aq)E° = -0.365 V
Ca²⁺(aq)+ 2e^- Ca(s)E° = -2.868 V
Pt²⁺(aq)+ 2e^- Pt(s)E° = 1.18 V
Br₂(l)+ 2e^- 2Br^-(aq)E° = 1.066 V

A)Pb(s)
B)Ca(s)
C)Pt(s)
D)Br^-(aq)
E)Pt²⁺(aq)

Question 54

Which equation is correct?

A)E°_cell = E°_anode - E°_cathode
B)E°_cell = E°_cathode + E°_anode
C)E°_cell = E°_cathode - E°_anode
D)E°_cell = E°_cathode / E°_anode

Question 55

Based on the data presented below,which is the strongest reducing agent? E°(V)
Al³⁺ + 3e^- → Al(s)-1.66
AgBr(s)+ e^- → Ag(s)+Br^- +0.07
Sn⁴⁺ + 2e^- → Sn²⁺ +0.14
Fe³⁺ + e^- → Fe²⁺ +0.77

A)Fe³⁺
B)Fe²⁺
C)Br^-
D)Al³⁺
E)Al(s)

Question 56

Which equation is correct?

A)E = -(RT/nF)lnK
B)E° = (RT/nF)lnK
C)E° = (RT/nF)lnQ
D)E = -(RT/nF)lnQ
E)E = E° + lnQ

Question 57

What is E°_cell for the following reaction,and is it spontaneous or nonspontaneous under standard-state conditions? 2Fe³⁺(aq)+ 2H₂O(l)→ H₂O₂(aq)+ 2H⁺(aq)+ 2Fe²⁺(aq)
Given:
H₂O₂(aq)+ 2H⁺(aq)+ 2e^-
2H₂O(l)E° = 1.77V
Fe³⁺(aq)+ e^- Fe²⁺(aq)E° = 0.77V

A)E°_cell = -1.00 V,nonspontaneous
B)E°_cell = -1.00 V,spontaneous
C)E°_cell = 1.00 V,nonspontaneous
D)E°_cell = 1.00 V,spontaneous
E)E°_cell = -0.23 V,nonspontaneous

Question 58

Based on the data presented below,which is the strongest oxidizing agent? Half-Reaction E°(V)
Al³⁺+ 3e^- → Al(s)-1.66
AgBr(s)+ e^- → Ag(s)+ Br^- +0.07
Sn⁴⁺+ 2e^- → Sn²⁺ +0.14
Fe³⁺+ e^- → Fe²⁺ +0.77

A)Fe³⁺
B)Fe²⁺
C)Br^-
D)Al³⁺
E)Al(s)

Question 59

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)

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

Question 60

What is ΔG° for the reaction of iron(II)ions with one mole of permanganate ions? (F = 96,500 C • mol^-1)
MnO₄^-(aq)+ 8H⁺(aq)+ 5e^- Mn²⁺(aq)+4H₂O(l)E° = 1.51V
Fe³⁺(aq)+ e^- Fe²⁺(aq)E° = 0.77V

A)-71.4 kJ
B)-286 kJ
C)-357 kJ
D)-428 kJ
E)None of these choices is correct.

Question 61

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

A)Pb(s)+ PbO₂(s)+ 4H⁺(aq)+ 2SO₄^2-(aq)→ 2PbSO₄(s)+ 2H₂O(l)
B)PbO₂(s)+ 4H⁺(aq)+ 2SO₄^2-(aq)+ 2e^- → PbSO₄(s)+ 2H₂O(l)
C)Pb(s)+ SO₄^2-(aq)→ PbSO₄(s)+ 2e^-
D)Pb(s)→ Pb(s)+ 2e^-
E)H₂(g)→ 2H⁺(aq)+ 2e^-

Question 62

What mass of Cu may be deposited from a Cu²⁺ solution during electrolysis by a current of 3.00 A for 10.0 hours?

A)63.6 g Cu
B)35.6 g Cu
C)6.4 g Cu
D)3.6 g Cu
E)71.2 g Cu

Question 63

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

A)Pb(s)+ PbO₂(s)+ 4H⁺(aq)+ 2SO₄^2-(aq)→ 2PbSO₄(s)+ 2H₂O(l)
B)PbO₂(s)+ 4H⁺(aq)+ 2SO₄^2-(aq)+ 2e^- → PbSO₄(s)+ 2H₂O(l)
C)Pb(s)+ SO₄^2-(aq)→ PbSO₄(s)+ 2e^-
D)Pb(s)→ Pb(s)+ 2e^-
E)H₂(g)→ 2H⁺(aq)+ 2e^-

Question 64

How much charge must pass through an electrolytic cell to reduce 0.44 mol Ca²⁺ ion to calcium metal?

A)1.9 ×10⁵ C
B)8.5 ×10⁴ C
C)2.1 ×10⁴ C
D)4.3 ×10⁴ C
E)0.88 C

Question 65

How many minutes would be required to electroplate 25.0 g of chromium by passing a constant current of 4.80 A through a solution containing CrCl₃?

A)483 min
B)161 min
C)322 min
D)2.01 × 10⁴ min
E)1.11 × 10⁴ min

Question 66

What quantity of charge is required to cause reduction of 0.20 mole of Cr³⁺ to Cr?

A)0.60 C
B)3.0 C
C)1.9 × 10⁴ C
D)5.8 × 10⁴ C
E)9.7 × 10⁴ C

Question 67

Which,if any,of the following metals would be capable of acting as a sacrificial anode when used with iron pipe?

A)
B)
C)
D)
E)

Question 68

What mass of nickel may be electroplated by passing a constant current of 7.2 A through a solution of NiSO₄ for 90.0 min?

A)0.20 g Ni
B)0.40 g Ni
C)12 g Ni
D)24 g Ni
E)47 g Ni

Question 69

Which metal is not capable of acting as a sacrificial anode when used with iron pipe?

A)
B)
C)
D)
E)

Question 70

A metal object is to be gold-plated by an electrolytic procedure using aqueous AuCl₃ electrolyte.How much gold may be deposited in 3.0 min by a constant current of 10.A?

A)6.2 × 10^-3 mol
B)9.3 × 10^-3 mol
C)1.8 × 10^-2 mol
D)3.5 × 10^-5 mol
E)1.6 × 10² mol

Question 71

How many faradays are transferred in an electrolytic cell when a current of 2.0 A flows for 12 hours? (1 faraday = 96,500 C)

A)24 faradays
B)8.6 × 10⁴ faradays
C)0.90 faradays
D)6.2 × 10^-3 faradays
E)1.1 faradays

Question 72

Predict the products obtained from the electrolysis of a 1 M AlBr₃ solution. Note that 2H₂O(l)+ 2e^- → H₂(g)+2OH^-(aq),E° = -0.83 V
O₂(g)+ 4H⁺(aq)+ 4e^- → 2H₂O(l),E° = +1.23 V
Br₂(l)+ 2e^- → 2Br^-(aq)E° = +1.08 V,and
Al³⁺(aq)+ 3e^- → Al(s)E° = -1.66 V

A)Al and Br₂
B)Al and O₂
C)H₂ and O₂
D)H₂ and Br₂
E)Al and H₂

Question 73

A voltaic cell consists of a Hg/Hg₂²⁺ electrode (E°= 0.85 V)and a Sn/Sn²⁺ electrode (E°= -0.14 V).Calculate [Sn²⁺] if [Hg₂²⁺] = 0.24 M and E_cell = 1.04 V at 25°C.

A)0.00010 M
B)0.00070 M
C)0.0049 M
D)0.030 M
E)0.050 M

Question 74

A voltaic cell consists of an Au/Au³⁺ electrode (E° = 1.50 V)and a Cu/ Cu²⁺ electrode (E° = 0.34 V).Calculate [Au³⁺] if [Cu²⁺] = 1.20 M and E_cell = 1.15 V at 25°C.

A)0.0010 M
B)0.0020 M
C)0.010 M
D)0.020 M
E)0.41 M

Question 75

Which is the Nernst equation?

A)
B)
C)
D)
E)None of these statements is correct.

Question 76

A voltaic cell consists of a Cd/Cd²⁺ electrode (E° = -0.40 V)and a Fe/Fe²⁺ electrode (E° = -0.44 V).If E_cell = 0 and the temperature is 25°C,what is the ratio [Fe²⁺]/[Cd²⁺]?

A)2.3 × 10¹
B)1.0 × 10¹
C)1.0
D)1.0 × 10^-1
E)5.0 × 10^-2

Question 77

Which one of the following statements relating to the glass electrode is correct?

A)The glass electrode detects hydrogen gas.
B)The glass of a glass electrode serves to conduct electrons.
C)When pH is measured,only a single electrode,the glass electrode,need be used.
D)The potential of the glass electrode varies linearly with the pH of the solution.
E)None of these statements is correct.

Question 78

What is the minimum voltage required for the electrolysis of 1.0 M NaCl in neutral solution? 2H₂O + 2Cl^- (1.0 M)→ H₂(1 atm)+ Cl₂(1 atm)+ 2OH^-(1 × 10^-7 M)
Note that
2H₂O(l)+ 2e^- → H₂(g)+2OH^-(aq),E° = -0.83 V,
2H₂O(l)+ 2e^- → H₂(g)+2OH^-(aq),E = -0.41 V([OH^-] = 1 × 10^-7M),
O₂(g)+ 4H⁺(aq)+ 4e^- →2H₂O(l),E° = +1.23 V,
Cl₂(g)+ 2e^- → 2Cl^-(aq)E° = +1.36 V,and
Na⁺(aq)+ e^- → Na(s)E° = -2.71 V

A)2.19 V
B)1.77 V
C)0.41 V
D)-0.41 V
E)-1.78 V

Question 79

What is the half-reaction that occurs at the cathode during the electrolysis of an aqueous sodium iodide solution? Half-Reaction E° (V)
2H₂O(l)+ 2e^- → H₂(g)+2OH^-(aq)-0.83
O₂(g)+ 4H⁺(aq)+ 4e^- →2H₂O(l)+1.23
Na⁺(aq)+ e^- → Na(s)-2.71
I₂(s)+ 2e^- → 2I^-(aq)+0.53

A)Na⁺ + e^- →
B)O₂(g)+ 4H⁺(aq)+ 4e^- → 2H₂O(l)
C)2H₂O + 2e^- → H₂ + 2OH^-
D)I₂ + 2e^- → 2I^-
E)2I^- → I₂ + 2e^-

Question 80

What mass of oxygen gas is produced in the electrolysis of water,for every gram of hydrogen gas formed? Reaction: 2H₂O(l)→ 2H₂(g)+ O₂(g)

A)32 g O₂
B)16 g O₂
C)64 g O₂
D)20 g O₂
E)8 g O₂