Reclutamiento

1. Identify the anode, the cathode and calculate the net cell potentials, Eo

net, for the following cells? Show all your calculations!

A. _Cr(s)|Cr 2+

(aq)||Sn2+(aq)|Sn(s) E°net =

B. _C(s)|SO₄ 2-

(aq), H+(aq), H2SO3(aq))||Co 2+

(aq)|Co(s) E°net =

C. _Ag(s)|Ag +

(aq)||MnO4-_{(aq), H}+_{(aq), Mn}2+_(aq)|Pt(

s) E°net =

D. _Pt(s)|H₂(g),OH -

(aq)||O2(g),OH -

(aq)|Pt(s) E°net =

E. _Pt(s)|Cr₂O₇ 2-

(aq), H+(aq), Cr3+(aq)||Pb2+(aq)|Pb(s) E°net =

F. Fe(s)|Fe 2+

(aq)||Cr2+(aq)|Cr(s) E°net =

2. Draw complete diagrams of the following voltaic cells (include: electrolyte components; ion flows; electron flow; all half & net reaction equations; E°net ; anode/cathode evidence of reaction; anode/cathode

labels & charges). Use a salt bridge not a porous cup. A. _Cu(s)|Cu2+(aq)||Ag+(aq)|Ag(s)

B. _C(s)|NO3-(aq), H+(aq)||Cd2+(aq)|Cd(s)

C. _Sn(s)|Sn 2+

(aq)||Pb2+(aq)|Pb(s)

D. _Al(s)|Al 3+

Diploma Examination Practice

Use the following diagram to answer the next four questions.

73. The net equation and the predicted voltage for the operating cell are

Use your recorded answer from the previous Multiple Choice to answer the next Numerical Response.

74. During the operation of this cell, if 0.354 mol of MnO4–(aq) were

consumed, then the mass of the copper electrode would decrease by __________ g.

75. During the operation of this cell,

A. electrons flow from the copper electrode to the carbon electrode

B. cations migrate toward the copper electrode C. anions migrate toward the carbon electrode D. the concentration of sulphate ions decreases

76. Which of the following statements does not apply to the operation of this cell?

A. The oxidation state of the reducing agent changes from 0 to +2.

Use the following diagram to answer the next question.

77. For this cell, the potential is A. +1.10 V

B. +0.42 V C. –0.42 V D. –1.10 V

Use the following information to answer the next question.

78. The materials necessary to construct an operational voltaic cell are, in numerical order, _____ , _____ , _____ , and _____ .

Use the following diagram to answer the next question.

79. Identify the part of the electrochemical cell, as numbered above that corresponds to the terms listed below.

Cathode __________ External electron circuit __________ Oxidizing agent __________

Anode __________

Use the following diagram to answer the next question.

80. Given that the reading on the voltmeter for this cell is +1.74 V, which of the following statements is correct?

A. The reduction potential of Q2+_{(aq) is +2.50 V.}

B. Zn(s) is a weaker reducing agent than Q(s).

C. Q2+(aq) would react spontaneously with Cu(s).

81. In an experiment, a student compares several electrochemical cells. Each cell contains two metal strips in their metallic ion solutions. A voltmeter is connected by a wire between the metal strips, and a salt bridge connects the solutions. The dependent (responding) variable is the

A. voltage

B. concentration of the solution

C. reaction of a metal and a metallic ion D. metal and metallic ion solution selected 82. In a voltaic cell, there is a conversion of

A. chemical energy to electrical energy in a spontaneous change B. chemical energy to electrical energy in a non-spontaneous

change

C. electrical energy to chemical energy in a spontaneous change D. electrical energy to chemical energy in a non-spontaneous

change

Use the following information to answer the next two questions.

83. As this cell operates, electrons flow from

A. X(s) to the inert electrode and the pH in the hydrogen half-cell increases B. X(s) to the inert electrode and the pH in the hydrogen half-cell decreases C. the inert electrode to X(s) and the pH in the hydrogen half-cell increases D. the inert electrode to X(s) and the pH in the hydrogen half-cell decreases 84. If the voltmeter reads +0.45 V under standard conditions, then X(s) is

most likely A. Ni(s) B. Fe(s) C. Zn(s) D. Mg(s)

Use the following information to answer the next question.

85. A student attempted to replicate a traditional Daniell Cell by setting up the electrochemical cell shown above. Under standard conditions, the electrical potential of the cell should be +/– __________ V.

Use the following diagram to answer the next question.

86. The cell in the diagram was constructed and connected by a chemistry student. The voltage of the cell remained at 0.00 V trial after trial. One possible reason for the malfunction of the cell was that the

A. concentrations of the solutions were too low B. solution in the U-tube was a non-electrolyte C. redox reaction was non-spontaneous D. voltmeter was connected backward

Use the following information to answer the next four questions.

87. The student chose zinc for the anode because zinc A. gains electrons easily

B. can be easily reduced C. is an oxidizing agent D. is a reducing agent

88. If the cell generates a voltage of +1.24 V under standard conditions, the half-reaction occurring at the cathode will have an electrode potential of

A. +2.00 V B. –2.00 V C. +0.48 V D. –0.48 V

89. If the zinc anode loses 200 g of mass during the operation of the cell, then the number of moles of electrons transferred is

A. 1.53 mol B. 3.06 mol C. 6.12 mol D. 12.2 mol

Use your recorded answer from the previous Multiple Choice to answer the next Numerical Response.

90. If the charge on the unidentified metal ion is 3+, then the number of moles of the metal produced when the zinc anode decreases in mass by 200 g is __________ mol.

Use the following information to answer the next question.

91. Identify the part of the voltaic cell, as numbered above, that corresponds to each of the descriptors listed below.

Anode __________ Cathode __________ Electron flow __________ Electrolyte __________