Free Printable AP Electrochemistry Review

Worksheets

AP Electrochemistry Review

Total questions: 107

Worksheet time: 1hrs 13mins

Name

Class

Date

Which species is oxidized in the following reaction?

2 Ag⁺(aq) + Cu(s) ⟶ 2 Ag(s) + Cu²⁺(aq)

Ag⁺

Cu²⁺

The diagram shows the electrolysis of lead(II) bromide using inert electrodes. Why does the lead(II) bromide need to be melted in order for this reaction to occur?

Bromine atoms in lead(II) bromide are converted to ions when it is melted

Electrons flow through the lead(II) bromide when it is melted

The ions in lead(II) bromide are mobile in the molten state.

There are no ions in solid lead(II) bromide

What is the product formed at the cathode during the electrolysis of molten magnesium fluoride?

magnesium

hydrogen

fluorine

oxygen

Reactions in voltaic cells are

spontaneous, redox reactions

non-spontaneous, redox reactions

spontaneous, non-redox reactions

non-spontaneous, non-redox reactions

Reactions in electrolytic cells are

spontaneous, redox reactions

non-spontaneous, redox reactions

spontaneous, non-redox reactions

non-spontaneous, non-redox reactions

Which of the following half reactions correctly represents a reduction half reaction?

Fe →Fe²⁺+ 2e^-

Pb⁴⁺ + 2e^- →Pb²⁺

2O^-2→O₂ + 4e^-

Fe + 3e^- →Fe³⁺

What is an anode?

It is the electrode where oxidation takes place.

It is the electrode where reduction takes place.

It is an aqueous solution containing an electrode.

It is the salt bridge that connects half-cells.

What is a cathode?

It is the electrode where oxidation takes place.

It is the electrode where reduction takes place.

It is an aqueous solution containing an electrode.

It is the salt bridge that connects half-cells.

Which half-reaction correctly represents oxidation?

(Select all that apply)

Ag ⟶ Ag⁺ + e^-

F₂ ⟶ 2 F^- + 2e^-

Au³⁺ + 3e^- ⟶ Au

Fe²⁺ + e^- ⟶ Fe³⁺

Au ⟶ Au³⁺ + 3e^-

10.

The overall reaction in an electrochemical cell is

Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)

As the reaction in this cell takes place, the

mass of the Zn(s) electrode decreases

Zn²⁺(aq) concentration remains the same

mass of the Cu(s) electrode decreases

Cu²⁺(aq) concentration remains the same

11.

Which species is oxidized in the following reaction?

2 Ag⁺(aq) + Cu(s) ⟶ 2 Ag(s) + Cu²⁺(aq)

Ag⁺

Cu²⁺

12.

The overall reaction in a galvanic cell is

2 Ag⁺(aq) + Cu(s) ⟶ 2 Ag(s) + Cu²⁺(aq)

Which of the following statements are correct as the cell operates?

The mass of the silver electrode increases.

The mass of the copper electrod increases.

The concentration of the silver ions increases.

The concentration of the copper ions increases.

Copper is the anode.

13.

What is the role of the salt bridge in a voltaic cell? (Check all that apply)

To allow the movement of water molecules between the two half cells

To allow the movement of electrons between the half cells

To allow the movement of ions to maintain charge neutrality

14.

What happens to the cell voltage when the salt bridge is removed?

The cell voltage drops to zero.

The cell voltage increases.

The cell voltage becomes negative.

The cell voltage is unchanged.

15.

Reduction happens at the ____.

anode

cathode

salt bridge

voltmeter

16.

Oxidation happens at the ____.

anode

cathode

salt bridge

voltmeter

17.

This electrode in a voltaic cell becomes more massive as the cell operates.

anode

cathode

18.

This electrode becomes less massive as a voltaic cell operates.

anode

cathode

19.

Which of the following statements correctly describes the movement of electrons in a voltaic cell?

Electrons flow through the salt bridge from the cathode to the anode

Electrons flow from left to right as the cell operates.

Electrons flow through the external wire from the anode to cathode

Electrons flow from right to left as the cell operates.

20.

In a voltaic cell, anions flow from the salt bridge into the _____ compartment.

cathode

anode

21.

In a voltaic cell, cations flow from the salt bridge into the ____ compartment.

cathode

anode

22.

Consider the diagram of a voltaic cell represented here. What reaction occurs at the anode?

Ag⁺ + e^- →Ag

Ag → Ag⁺ + e^-

Ni²⁺ + 2e^- → Ni

Ni → Ni²⁺ + 2e^-

23.

A voltaic cell is established based on the redox reaction below.

Mg(s) + Fe²⁺(aq) → Mg²⁺(aq) + Fe(s)

Which statements are correct as the cell runs? (Select all that apply)

Magnesium atoms lose electrons.

The mass of the iron electrode decreases.

Electrons flow from the iron electrode to the magnesium electrode.

Anions flow into the iron half-cell.

Anions flow into the magnesium half-cell.

24.

Calculate the E_cell for the following galvanic cell.

using a zinc half cell with 1.0 M Zn(NO₃)₂ and a silver half cell with 0.1M AgNO₃

E_Ag⁺| _Ag = +1.08V and E_Zn²⁺|_Zn = -0.76V

0.32 V

0.33 V

1.84 V

1.85 V

25.

Calculate the cell potential, E_cell of the electrochemical cell in which reaction

Pb²⁺ (aq) + Cd (s) → Pb (s) + Cd²⁺ (aq)

Given that E^o_cell = +0.277 V,

[Cd²⁺] = 0.02M, and [Pb²⁺] = 0.2M.

0.207 V

0.255 V

0.307 V

0.355 V

26.

A voltaic cell was set up using a zinc electrode immersed in a zinc nitrate solution and a nickel electrode immersed in a nickel(II) nitrate solution.

Ni²⁺ + Zn ⟶ Ni + Zn²⁺

Which of the following would give a cell voltage that is greater than the standard cell potential?

Increase temperature

Decrease the concentration of Ni²⁺

Increase the concentration of Ni²⁺

Increase the concentration of Zn²⁺

27.

The standard electrode potential of Pb²⁺/ Pb and Cu²⁺/ Cu is -0.13V and +0.34 V respectively. Identify the anode and the cathode for the galvanic cell.

Anode: Pb²⁺, Cathode: Cu

Anode: Pb, Cathode: Cu

Anode: Pb, Cathode: Cu²⁺

28.

What is the Nernt Equation for the following reaction?

2Al (s) + 6H⁺ (aq) $\rightarrow$ 2Al³⁺ (aq) + 3H₂(g)

E_cell= E⁰_cell- $\frac{RT}{nF}$ ln $\frac{\left[Al^{3+}\right]^2}{\left[H^+\right]^6}$

E_cell = E⁰_cell - $\frac{RT}{nF}$ ln $\frac{\left[H^+\right]^6}{\left[Al^{3+}\right]^2}$

E_cell = E⁰_cell - $\frac{RT}{nF}$ ln $\frac{\left[H^+\right]^6}{\left[Al^{3+}\right]^2\ \left(P_{H_2}\right)^3}$

E_cell = E⁰_cell- $\frac{RT}{nF}$ ln $\frac{\left[Al^{3+}\right]^2\ \ \left(P_{H_2}\right)^3}{\left[H^+\right]^6}$

29.

Given the half-cell equation:

Cu²⁺ (aq) +2e $\rightarrow$ Cu (s)

Determine the coulombs required to produced 0.10 mol of Cu

19300 C

4825 C

482500 C

193000 C

30.

What is an anode?

It is the electrode where oxidation takes place.

It is the electrode where reduction takes place.

It is an aqueous solution containing an electrode.

It is the salt bridge that connects half-cells.

31.

What is a cathode?

It is the electrode where oxidation takes place.

It is the electrode where reduction takes place.

It is an aqueous solution containing an electrode.

It is the salt bridge that connects half-cells.

32.

Electrons always flow from

cathode to anode

anode to cathode

33.

Oxidation occurs at the

anode

cathode

34.

Electrons are gained at the

anode

cathode

35.

Given their standard reduction potentials, which of the species is going to be oxidized?

Cu²⁺/Cu = 0.34V

Zn²⁺/Zn = -0.76V

CuSO4

ZnSO4

36.

What reaction occurs at the anode?

Ag⁺/Ag = 0.80V

Ni²⁺/Ni = -0.25V

Ag⁺ + e^- →Ag

Ag → Ag⁺ + e^-

Ni²⁺ + 2e^- → Ni

Ni → Ni²⁺ + 2e^-

37.

A current of 5.0 A flows for 4 hours through 5.0L of a 2.0M aqueous solution of copper (II) sulfate. Calculate the mass of copper deposited at the cathode.

21.69 g

22.69 g

23.69 g

38.

When a certain amount of electric charge flows through an aqueous solution of silver nitrate, 3.24 g of silver is deposited on the cathode.

Calculate the mass of aluminium, Al that will be deposited by the same quantity of charge.

0.27 g

0.29 g

0.40 g

39.

Calculate the time taken to produce 18.0 g of silver from silver nitrate by a current of 0.900 A.

1.58 X 10⁴ s

1.68 X 10⁴ s

1.78 X 10⁴ s

40.

Cell potentials should be (a) for the reaction to be spontaneous.

41.

ΔG should be (a) , for the reaction to be spontaneous.

42.

In a copper plating experiment in which copper metal is deposited from copper (II) ion solution, the system is run for 2.600 hours at a current of 12.00 A. What mass of copper is deposited?

---

NOTE: Use Faraday Constant Value 96, 485 C

(Report your answer with 4 sig figs)

(a)

43.

If a current of 15.0 A is run through electrolysis cell for 2.00 hours, how many moles of electrons have moved? (Answer with "moles of e" as a UNIT, 3 sig figs)

(a)

44.

Consider the reaction

Pb(s) + 2Ag⁺(aq) ⟶ Pb²⁺(aq)+ 2Ag(s)

If E^o_cell = 0.93 V

Calculate ΔG° at 298.15 K for this reaction.

---

Ag⁺(aq) + e^- ⟶ Ag(s) [ E° =0.80 V]

Pb²⁺(aq) + 2e ⟶ Pb(s) [E° = - 0.13 V]

(Report your answer in kJ with 2 sig figs))

(a)

45.

A voltaic cell is made by connecting a Mn/Mn²⁺ half cell with a Pb/Pb²⁺ half-cell. Which statement is correct?

Mn²⁺ + 2 e- ⟶ Mn E^o = -1.19V

Pb²⁺ + 2 e- ⟶ Pb E^o = -0.13 V

Mn is oxidized and voltage is 1.06 V

Pb is oxidized and voltage is 1.06 V

Mn is oxidized and voltage is 1.32 V

Pb is oxidized and voltage is 1.32 V

46.

As an element is oxidized, its oxidation number

decreases as electrons are lost

increases as electrons are lost

decreases as electrons are gained

increases as electrons are gained

47.

A salt bridge is required to measure the cell potential of an electrochemical cell. The function of the salt bridge is to ____.

to provide large surface area for reactions to occur

to allow electrons to flow through from one cell to another cell

to allow ions to pass through and to maintain the ionic balance

to increase the voltage of the electrochemical cell

48.

What is an electrolytic cell?

a cell that converts chemical energy into electrical energy

a cell that converts electrical energy into electrical energy

a cell that converts electrical energy into chemical energy

A cell that converts kinetic energy into potential energy.

49.

Consider the cell reaction 2Al(s) + 3Mn²⁺(aq) → 2Al³⁺(aq) + 3Mn(s)

Predict whether E_cell is larger or smaller than E°_cell

if[Al³⁺] = 2.0 M, [Mn²⁺ ] = 1.0 M

E_cellissmaller than E°_cell

E_cellis larger than E°_cell

E_cellis the same as E°_cell

50.

Consider the cell reaction Pb(s) + Mn²⁺(aq) → Pb²⁺(aq) + Mn(s)

Predict whether E_cell is larger or smaller than E°_cell

if [Pb²⁺] = 0.50 M, and [Mn²⁺] = 0.50 M

E_cell is smaller than E°_cell

E_cell is larger than E°_cell

E_cell is the same as E°_cell

51.

Electrolytic cells are:

thermodynamically favorable (+Ecell)

thermodynamically non-favorable (-Ecell)

at equilibrium (Ecell = 0.00)

not a type of electrochemical cell

52.

How do we determine the number of moles of electrons transferred in a redox reaction?

balance the reaction for mass only

balance the reaction for charge only

balance the reaction for mass and charge and then cancel out the same number of electrons on both sides, this is the coefficient on electrons

balance the reaction for mass and charge and then add the number of electrons together

53.

Given the standard reduction potentials at 25℃ , calculate the standard cell potential, E_cell.

$Mg_{\left(aq\right)}^{2+}+2e^-\rightarrow Mg_{\left(s\right)}$ E°= -2.37V

$Al_{\left(aq\right)}^{3+}+3e^-\rightarrow Al_{\left(s\right)}$ E°= -1.66V

- 0.71V

- 4.03V

+0.71V

+4.03V

54.

Which of the following statements accurately describes the Nernst equation shown below?

At equilibrium, E_cell calculates to a value of 0 and the battery is considered dead because Q becomes K_eq and K_eq has a value of 0.

Increasing the concentration of the reactants will increase the value of E_cell.

This equation is used to figure out the standard cell potential at any concentration, partial pressure or temperature.

At standard conditions, E_cell = E°_cell because all the concentrations are 1 M at an ambient temperature of 273 K.

55.

What is the value of the equilibrium constant, K, if E°cell=+0.71V at 298 K.

Overall eq: $3Mg_{\left(s\right)}+2Al_{\left(aq\right)}^{3+}\rightarrow3Mg_{\left(aq\right)}^{2+}+2Al_{\left(s\right)}$ (F = 96485 C/ mol $\overline{e}$ ; R= 8.31 J/(mol.K))

$1.212\times10^{72}$

$-1.212\times10^{72}$

$1.101\times10^{36}$

$-1.101\times10^{36}$

56.

An AP chemistry student sets up a galvanic cell using two standard half-cells with half reactions.

Half-cell 1: Cr³⁺(aq)+e^-→Cr²⁺(aq)

Half-cell 2: Cr(s)→Cr²⁺(aq)+2e^-

Suitable materials for the electrodes of the two half-cells are

Half-cell 1: Platinum; Half-cell 2: Platinum

Half-cell 1: Platinum; Half-cell 2: Chromium

Half-cell 1: Chromium; Half-cell 2: Chromium

Half-cell 1: Chromium; Half-cell 2: Platinum

57.

Calculate the standard cell potential for a voltaic cell using a zinc half-cell and a cadmium half-cell.

Zn²⁺(aq) + 2e → Zn(s) Eº = – 0.76 V

Cd²⁺(aq) + 2e → Cd(s) Eº = – 0.40 V

E^o_cell = -0.36 V

E^o_cell= -1.16 V

E^o_cell = +1.16 V

E^o_cell = +0.36 V

58.

Which of the pairs give the highest value for the standard cell voltage?

Al³⁺(aq) + 3e → Al(s) E^o_cell = - 1.66 V

Cu²⁺(aq) + 2e → Cu(s) E^o_cell = + 0.34 V

Ni²⁺(aq) + 2e → Ni(s) E^o_cell = – 0.25 V

Br₂(l) + 2e → 2Br^-(aq) E^o_cell = + 1.07 V

Al and Ni

Cu and Br₂

Al and Br₂

Cu and Ni

59.

Calculate Ecell for the following reaction and predict whether the following reaction is thermodynamically favorable.

2Ag(s) + Br₂(g) ⟶ 2Ag⁺(aq) + 2Br^-(aq)

Eº_Ag+/Ag = + 0.80 V Eº _Br2/_Br-= + 1.07 V

Eº cell= + 0.27 V (not thermodynamically favorable)

Eº cell= + 0.27 V (thermodynamically favorable)

Eº cell= - 0.37 V (not thermodynamically favorable)

Eº cell= - 0.37 V (thermodynamically favorable)

60.

Consider the cell reaction

2Al(s) + 3Mn²⁺(aq) → 2Al³⁺(aq) + 3Mn(s) at non-standard conditions. Calculate the value of E_cell if the initial solutions concentrations were:

[Al³⁺] = 2.0 M [Mn²⁺ ] = 1.5 M

Al³⁺/Al E⁰= -1.66V

Mn²⁺/Mn E⁰= -1.19 V

0.699 V

0.50 V

0.469 V

0.741 V

61.

The electrolysis of molten NaCl with carbon electrodes was run for 30. minutes with current of 5.0 A . Find the mass of sodium deposited on the cathode.

2.14 gram

5.25 gram

3.95 gram

4.52 gram

62.

Calculate the mass of copper deposited at cathode during electrolysis using CuSO₄ for 20. minutes with a current of 3.0A.

1.79 g

0.79 g

1.18 g

9.71 g

63.

Two copper electrodes were immersed in a copper (II) sulfate solution. If 0.39 g of copper was deposited on the cathode after the cell was operated for 1.5 hours, calculate the average current used (in amperes) for this electrolysis process.

0.22 A

2.0 A

0.15 A

0.3 A

64.

Chromium (III) chloride solution was electrolysed using a current of 10. A for 50. minutes. Calculate the theoretical mass of chromium metal that will deposit on the cathode.

16.2 g

8.08 g

4.38 g

0.0898 g

5.38 g

65.

Will this reaction be thermodynamically favorable?

Fe²⁺(aq) + Co(s) ⟶ Fe(s) + Co²⁺(aq)

GIVEN:

Co²⁺_(aq) / Co_(s) E^o = -0.28 V

Fe²⁺_(aq) / Fe_(s) E^o= -0.44 V

The reaction is thermodynamically favorable because the value of E^o_cell is +0.16

The reaction is thermodynamically favorable because the value of E^o_cell is +0.72

The reaction is not thermodynamically favorable because the value of E^o_cell is -0.72

The reaction is not thermodynamically favorable because the value of E^o_cell is -0.16

66.

An aqueous solution of CuSO₄ is electrolysed

using a current of 0.150 A for 5 hours. Calculate the mass of copper deposited at cathode.

(Molar mass of Cu = 63.6 g/mol)

0.0140 g

0.8897 g

0.4449 g

1.7794 g

67.

A voltaic cell is constructed using a silver electrode immersed in a 0.10 M solution of silver nitrate and a copper strip immersed in a solution of 1.0M copper(II) nitrate. The mass of the silver electrode is observed to increase.

Which of the following correctly identifies the anode and the cathode in this cell?

Ag is the anode and Cu is the cathode

Cu is the anode and Ag is the cathode

Ag is the anode and Cu²⁺ is the cathode

Cu is the anode and Ag⁺ is the cathode

68.

What would be the theoretical cell potential of a galvanic cell constructed with a silver electrode immersed in 1M silver nitrate solution and a nickel electrode immersed in a 1.0M nickel(II) nitrate solution?

Ag⁺/Ag E^o = 0.80V

Ni²⁺/Ni E^o = -0.25V

1.05V

-1.05V

0.55V

-0.55V

69.

A galvanic cell was constructed with a zinc half cell with 1.0 M Zn(NO₃)₂ and a silver half cell with 0.1M AgNO₃

E_Ag⁺| _Ag = +1.08V and E_Zn²⁺|_Zn = -0.76V

Which of the following correctly compares the cell voltage to the standard cell potential and provides a correct explanation?

E_cell < E^o_cell, because Q > 1

E_cell < E^o_cell, because Q < 1

E_cell > E^o_cell, because Q < 1

70.

Consider the following reaction in a galvanic cell:

Zn+ Cu⁺² →Zn²⁺ + Cu E∘ =1.10V

What is the Gibb's free energy for the reaction under standard conditions?

106.15kJ/mol

212.3kJ/mol

−212.3kJ/mol

−106.15kJ/mol

71.

Suppose that a reaction with an equilibrium constant equal to 4.5∗10⁶ occurs while at standard state conditions.

Which of the following is true regarding this reaction?

The Gibbs free energy change for this reaction is negative and the reaction is spontaneous

The Gibbs free energy change for this reaction is positive and the reaction is nonspontaneous

The Gibbs free energy change for this reaction is negative and the reaction is nonspontaneous

The Gibbs free energy change for this reaction is positive and the reaction is spontaneous

72.

Given the electrochemical reaction shown, what is the standard free energy change ΔG° if

E˚ = +1.61 V?

Mg / Mg ²⁺_(aq) // Zn²⁺_(aq) / Zn

E˚ = +1.61 V

-311 kJ/mol

+311 kJ/mol

-155 kJ/mol

+155 kJ/mol

none of the above

73.

What is ΔG° for the following balanced reaction, if

E˚ = +2.431 V?

Al_(s)+ Fe³⁺_(aq) → Al³⁺_(aq) + Fe_(s) E˚ = +2.431 V

-704 kJ/mol

+704 kJ/mol

-235 kJ/mol

-469 kJ/mol

none of the above

74.

When a voltaic cell reaches equilibrium, __________

E= 0

E= K

E_cell= 0

Ec_ell = Q

E_cell = K

75.

ΔG should be (a) for the reaction to be spontaneous.

Choose from the below words

negative

positive

zero

76.

Calculate for the Gibbs free energy, answer in kJ.

(a)

77.

In a copper plating experiment in which copper metal is deposited from copper (II) ion solution, the system is run for 2.600 hours at a current of 12.00 A. What mass of copper is deposited?

---

NOTE: Use Farad Constant Value 96, 485 C

(Answer with "g Cu" as a UNIT, 4 sig figs)

(a)

78.

If a current of 15.0 A is run through electrolysis cell for 2.00 hours, how many moles of electrons have moved? (Answer with "moles of e" as a UNIT, 3 sig figs)

(a)

79.

The diagram shows the electrolysis of molten lead(II) bromide. What process occurs at the cathode in this cell?

2 Br- ⟶ Br₂ + 2e-

Br₂ + 2 e- ⟶ 2Br-

Pb²⁺ + 2 e- ⟶ Pb

Pb ⟶ Pb²⁺ + 2 e-

80.

Consider a voltaic cell, represented by the following net ionic equation

Pb²⁺ (aq) + Cd (s) → Pb (s) + Cd²⁺ (aq)

Given that E^o_cell = +0.277 V,

if the initial [Cd²⁺] is 0.02M and the initial [Pb²⁺] = 0.2M, which of the following correctly compares the cell voltage to the standard cell potential and provides a correct explanation?

E_cell< E^o_cell because Q < 1

E_cell < E^o_cell because Q < 1

E_cell > E^o_cell because Q < 1

E_cell < E^o_cell because Q < 1

E_cell = E^o_cell because Q = 1

81.

Consider the following reaction in a galvanic cell:

Zn+ Cu⁺² →Zn²⁺ + Cu E^∘ =1.10V

Which of the following correctly describes ΔG and K for this reaction?

ΔG > 0 and K > 1

ΔG < 0 and K < 1

ΔG < 0 and K > 1

ΔG > 0 and K < 1

82.

The diagram shows the electrolysis of molten lead(II) bromide.

Which of the following correctly describes ΔG and K for this reaction?

ΔG > 0 and K > 1

ΔG < 0 and K < 1

ΔG < 0 and K > 1

ΔG > 0 and K < 1

83.

Consider a voltaic cell, represented by the following net ionic equation

Pb²⁺ (aq) + Cd (s) → Pb (s) + Cd²⁺ (aq)

What happens to the concentration of the ions in each half cell?

(Select all that apply)

[Pb²⁺] increases in the cathode compartment

[Pb²⁺] decreases in the cathode compartment

[Cd²⁺] increases in the anode compartment

[Cd²⁺] decreases in the anode compartment

[Pb²⁺] decreases in the anode compartment

84.

Consider a galvanic cell with the following reaction.

Al_(s)+ Fe³⁺_(aq) → Al³⁺_(aq) + Fe_(s)

As the cell operates, the mass of the aluminum electrode decreases. Which of the following correctly explains this observation?

aluminum ions go into solution in the anode compartment

aluminum atoms deposit on the anode

aluminum ions travel through the wire to the cathode

iron(II) ions travel through the wire to the cathode

iron atoms deposit on the cathode

85.

A voltaic cell was set up using a zinc electrode immersed in a zinc nitrate solution and a nickel electrode immersed in a nickel(II) nitrate solution.

Ni²⁺ + Zn ⟶ Ni + Zn²⁺

Which of the following would give a cell voltage that is less than the standard cell potential?

Decrease temperature

Decrease the concentration of Ni²⁺

Increase the concentration of Ni²⁺

Increase the concentration of Zn²⁺

86.

What is the standard cell potential of Cell C?

1.05V

2.03V

0.93V

4.45V

87.

In galvanic cells A and B, which of the following takes place in half-cell 3?

Oxidation occurs in both cell A and cell B.

Reduction occurs in both cell A and cell B.

Oxidation occurs in cell A, and reduction occurs in cell B.

Reduction occurs in cell A, and oxidation occurs in cell B.

88.

In galvanic cells B and C, which of the following takes place in half-cell 1?

Oxidation occurs in both cell B and cell C.

Reduction occurs in both cell B and cell C.

Oxidation occurs in cell B and reduction occurs in cell C.

Reduction occurs in cell B and oxidation occurs in cell C.

89.

If the half-cell containing 1.00M Cr(NO₃)₃ in galvanic cells A and B is replaced with a half-cell containing 0.100M Cr(NO₃)₃, what will be the effect on the cell voltage of the two galvanic cells?

The voltage will increase in both cells.

The voltage will decrease in both cells.

The voltage will increase in cell A and decrease in cell B.

The voltage will decrease in cell A and increase in cell B.

90.

If the half-cell containing 1.00 M Ni(NO₃)₂ in galvanic cells 2 and 3 is replaced with a half-cell containing 0.100M Ni(NO₃)₂, what will be the effect on the cell voltage of the two galvanic cells?

The voltage will increase in both cells.

The voltage will decrease in both cells.

The voltage will decrease in cell B and increase in cell C.

The voltage will increase in cell B and decrease in cell C.

91.

A galvanic cell based on the reaction represented above was constructed from zinc and copper half–cells. The observed voltage was found to be 1.00 volt instead of the standard cell potential, E^o, of 1.10 volts. Which of the following could correctly account for this observation?

Zn(s) + Cu²⁺(aq) ⟶ Zn²⁺(aq) + Cu(s)

The copper electrode was more massive than the zinc electrode

The Zn²⁺ solution was more concentrated than the Cu²⁺ solution.

The solutions in the half–cells had different volumes.

The salt bridge was not in contact with the solutions in the half-cells

The Zn²⁺ solution was less concentrated than the Cu²⁺ solution.

92.

Cu(s) + 2 Ag⁺ (aq)⟶ Cu²⁺(aq) + 2 Ag(s)

If the equilibrium constant for the reaction above is 3.7x10¹⁵, which of the following correctly describes the standard voltage, E^o, and the standard free energy change, ΔG^o, for this reaction?

E^o is positive and ΔG^o is negative.

E^o and ΔG^o are both negative.

E^o is negative and ΔG^ois positive.

E^o and ΔG^o are both zero

E^o and ΔG^o are both positive

93.

Cu²⁺(aq) + 2 Ag(s) ⟶ Cu(s) + 2 Ag⁺ (aq)

If the equilibrium constant for the reaction above is 2.7x10^-16, which of the following correctly describes the standard voltage, E^o, and the standard free energy change, ΔG^o, for this reaction?

E^o is positive and ΔG^o is negative.

E^o and ΔG^o are both negative.

E^o is negative and ΔG^ois positive.

E^o and ΔG^o are both zero

E^o and ΔG^o are both positive

94.

Which of the following correctly describes the values of ΔG and K_eq as the electrolysis reaction proceeds?

ΔG is positive and K_eq is less than 1.

ΔG is positive and K_eq is greater than 1.

ΔG is negative and K_eq is less than 1.

ΔG is negative and K_eq is greater than 1.

95.

Which of the following correctly represents the balanced net ionic equation for the electrolysis reaction?

2 H₂O + 2 Cu²⁺ ⟶ 4 H⁺ + 2 Cu + O₂

4 H⁺ + 2 Cu + O₂(g) ⟶ 2 H₂O + 2 Cu²⁺

2 H₂O + Cu²⁺ ⟶

4 H⁺ + Cu + O₂

2H⁺ + 2 Cu + O₂ ⟶ H₂O + 2 Cu²⁺

96.

Which of the following correctly describes the electrochemical cell?

Copper ions are reduced at the cathode, and oxygen gas is generated at the anode.

Copper metal is reduced at the anode, and oxygen gas is generated at the cathode.

Copper ions are oxidized at the cathode, and water is oxidized at the anode.

Copper metal is oxidized at the anode, and water is reduced at the cathode.

97.

Which of the following changes will result in an increase in the cell voltage?

Adding 50.0 mL of 5.0M Cu(NO₃)₂ to the right beaker

Adding 50.0 mL of 5.0M Pb(NO₃)₂ to the left beaker

Increasing the mass of the copper strip

Decreasing the mass of the lead strip

98.

What will be the effect on the cell voltage if a 50.0 mL sample of 5M Pb(NO₃)₂ is added to the left beaker?

E_cell will increase.

E_cell will decrease but remain above zero.